TL;DR: The best AI Firefox extensions ranked by real adoption are Grammarly: AI Writing and Grammar Checker App (502,948 daily users, quality score 94/100), DeepL: AI translator and writing assistant (157,006 users, 84/100), and 划词翻译 (26,686 users, 70/100). Across all 89 AI Firefox add-ons we track, one add-on holds 56.9% of the audience and none carry Mozilla’s Recommended badge.
Last updated: 7 August 2026. Data snapshot: 7 August 2026, pulled from the Mozilla Add-ons (AMO) public API. Add-ons ranked: 89. Combined daily active users: 883,480.
Most “best AI Firefox extensions” lists are somebody’s opinion with affiliate links attached. This one is a measurement. Every number below comes from Mozilla’s own public API, and I have been snapshotting it daily since 18 July 2026 so I can show you not just who is big, but who is actually growing.
I have tested more than 500 AI and SaaS tools with my own money over 15 years in software and SEO, and the pattern I keep finding is that adoption and opinion disagree more often than vendors would like. Firefox is the clearest example I have seen yet. Read on for the full ranked directory, the formula behind it, and the five things the raw data says that no editorial roundup will tell you.
The Numbers Worth Quoting
- 89 AI Firefox add-ons met the inclusion bar as of 7 August 2026, with 883,480 combined daily active users.
- Grammarly: AI Writing and Grammar Checker App alone accounts for 56.9% of all AI add-on usage on Firefox (502,948 of 883,480 daily users).
- Language & Translation is 79.7% of the audience from just 13 add-ons, while Search Tools has the most add-ons (20) and only 6.9% of users.
- Zero of the 89 carry Mozilla’s Recommended badge, the label Mozilla gives add-ons that pass extra human review.
- 43 of 89 add-ons are built around ChatGPT, 22 reference Claude, and 16 reference Gemini.
- The median AI Firefox add-on has 1,572 daily users. Only three clear 10,000, and 31 sit under 1,000.
- 24 of 89 have not shipped an update in over 12 months, including eight with more than 2,000 daily users.
- Over 21 consecutive days of snapshots, 28 add-ons grew and 57 shrank. The fastest riser gained 75.8%.
- 7,195 total reviews across all 89 add-ons, from 86 distinct developers.
Every one of those figures is reproducible from the tables further down this page. If you want to cite them, the methodology and attribution line is at the bottom.
What Counts as an AI Firefox Add-on?
An AI Firefox add-on is a browser extension distributed through Mozilla Add-ons that adds AI capability directly into Firefox, usually as a sidebar, a toolbar button, or a right-click menu, so you do not need a separate tab or desktop app. Typical jobs are chat, writing help, summarizing, and translation.
The inclusion rule for this directory is deliberately strict, and it is the reason the count is 89 rather than several hundred. An add-on qualifies only if it is a genuine AI tool: either an AI term appears in its name, or a specific AI product such as ChatGPT, Claude, or Gemini appears in its description. Two categories get removed by hand:
- Anti-AI utilities. Extensions whose whole purpose is to hide, block, or strip AI features answer a different question than “which AI tools should I add?”
- Incidental AI mentions. Ad blockers, password managers, VPNs, and screenshot tools that name-drop AI in their store copy but do not do anything with it.
That means popular Firefox extensions you might expect to see are missing on purpose. This is an AI-only directory, not a general “best Firefox extensions” list.
The 10 Best AI Firefox Add-ons Right Now
| Rank | AI Firefox add-on | What it does | Rating | Daily users | Quality score |
|---|---|---|---|---|---|
| 1 | Grammarly: AI Writing and Grammar Checker App | Language & Translation | 4.1/5 (3,211) | 502,948 | 94/100 |
| 2 | DeepL: AI translator and writing assistant | Language & Translation | 4.2/5 (1,028) | 157,006 | 84/100 |
| 3 | 划词翻译 | Language & Translation | 4.3/5 (335) | 26,686 | 70/100 |
| 4 | Page Assist - A Web UI for Local AI Models | Other | 4.7/5 (76) | 8,673 | 62/100 |
| 5 | Simplify Copilot - Autofill job applications | Other | 4.2/5 (144) | 9,562 | 61/100 |
| 6 | ChatGPT to PDF | Other | 4.5/5 (51) | 9,344 | 60/100 |
| 7 | chessvision.ai Chess Position Scanner | Games & Entertainment | 4.8/5 (79) | 4,234 | 58/100 |
| 8 | Definer: Word Translator, Ask AI, Popup Dictionary | Search Tools | 4.6/5 (144) | 3,398 | 57/100 |
| 9 | AI Side Bar Go | Search Tools | 4.3/5 (23) | 6,880 | 55/100 |
| 10 | Freespoke - AI Search Tool | Search Tools | 4.7/5 (45) | 4,130 | 55/100 |
Three things stand out in that top ten.
First, the top three are all language tools, and they are not close to the rest. Grammarly: AI Writing and Grammar Checker App and DeepL: AI translator and writing assistant together hold 75% of every daily user in the directory. Everything from rank four down operates at a completely different scale.
Second, quality score drops off a cliff. Rank one scores 94/100, rank four scores 62/100, and rank ten scores 55/100. There is no crowded race at the top of AI on Firefox. There is one giant, one strong runner-up, and then a long tail.
Third, the middle of the top ten is genuinely surprising. A chess position scanner and a job-application autofill tool outrank most of the ChatGPT sidebars, because they have real user bases and better ratings than the sidebar category average.
Here is what I would actually say about the six add-ons in this directory I have used enough to have an opinion on:
Grammarly (rank 1) The default pick for most people. The free tier alone catches the errors that matter; the paid tier is really about tone and rewriting, not correctness. Works the same on Firefox as Chrome.
DeepL (rank 2) The translation quality is the reason to install this over a generic translator. Free tier is generous for occasional use; the writing-assistant side is newer and less essential than the core translate.
Page Assist (rank 4) The standout for privacy-minded users: it gives you a chat UI for local models (Ollama and friends) so your prompts never leave your machine. Needs a local model running, so it is not a plug-and-play pick for everyone.
WebChatGPT (rank 14) Adds live web results and a prompt/preset library to ChatGPT. Genuinely useful, but it is a companion to ChatGPT, not a standalone assistant. Check permissions before installing any ChatGPT add-on.
AI Subtitles & Immersive Translate (rank 15) Best-in-class for bilingual subtitles and inline video/page translation while you learn a language. Freemium, and the free limits are enough to try before you commit.
Superpower ChatGPT (rank 50) A power-user layer over ChatGPT: folders, search, bulk export, prompt history. Only worth it if you live in ChatGPT daily; casual users will not miss it.
How Is the Quality Score Calculated?
The Quality Score is a 0 to 100 composite of three public Mozilla Add-ons metrics: adoption at 45% weight, rating quality at 35%, and review-volume trust at 20%. No add-on can pay to raise its score or its placement, and the same formula runs on all 89 entries so the numbers are directly comparable.
The three inputs each answer a different question:
- Adoption (45%) uses average daily active users as reported by the AMO API, log-scaled and normalized across the dataset. Log-scaling matters: without it, Grammarly: AI Writing and Grammar Checker App’s half-million users would flatten every other add-on to zero and the ranking would just be a user-count list.
- Rating quality (35%) is the star rating out of 5, scaled to 100.
- Review-volume trust (20%) is the log of review count, normalized across the dataset. This is what stops a 5.0 rating from two reviews outranking a 4.5 from two thousand.
Two honest limitations. We do not compute a security score, because Mozilla publishes no per-add-on vulnerability feed comparable to the one we use for AI WordPress plugins. And the last-updated date in our tables comes straight from AMO with no adjustment.
The weighting is identical to the one behind our AI Chrome extensions leaderboard, which means a score of 62 means the same thing on both pages and you can compare a Firefox add-on against its Chrome counterpart directly.
Which Categories Hold the Most AI Firefox Add-ons?
Search Tools holds the most AI Firefox add-ons at 20, followed by Developer Tools at 15 and Language & Translation at 13. Adoption tells the opposite story: Language & Translation accounts for 703,850 of the 883,480 daily users, or 79.7% of the audience, from those 13 add-ons alone.
| Category | Add-ons | Combined daily users | Share of all users | Busiest add-on |
|---|---|---|---|---|
| Search Tools | 20 | 60,950 | 6.9% | Copilot Launcher Button (7,137) |
| Developer Tools | 15 | 23,779 | 2.7% | Speed Booster for ChatGPT - Fix Lag & Export (3,324) |
| Language & Translation | 13 | 703,850 | 79.7% | Grammarly: AI Writing and Grammar Checker App (502,948) |
| Other | 12 | 43,395 | 4.9% | Simplify Copilot - Autofill job applications (9,562) |
| News & Blogging | 11 | 20,973 | 2.4% | YouTube Summary with ChatGPT & Claude (4,573) |
| Appearance | 7 | 11,361 | 1.3% | Claude Usage Tracker (3,474) |
| Download Management | 4 | 7,035 | 0.8% | AI Exporter - Gemini to PDF & Sync to Notion (3,972) |
| Privacy & Security | 2 | 1,430 | 0.2% | Duck.ai Chat on Sidebar (888) |
| Games & Entertainment | 1 | 4,234 | 0.5% | chessvision.ai Chess Position Scanner (4,234) |
| Social & Communication | 1 | 3,518 | 0.4% | ChatGPT Export (3,518) |
| Tabs | 1 | 1,547 | 0.2% | Pinned ChatGPT (1,547) |
| Photos, Music & Video | 1 | 770 | 0.1% | Save ChatGPT as PDF (770) |
| Bookmarks | 1 | 638 | 0.1% | AI Chat Exporter (638) |
| All 13 categories | 89 | 883,480 | 100% | Grammarly (502,948) |
The gap between those two rankings is the single most useful thing in this dataset. Developers keep building AI search assistants and ChatGPT sidebars because they are the obvious thing to build. Firefox users keep installing writing and translation tools because that is what they actually need in a browser.
Look at the ratio. Language & Translation averages 54,142 daily users per add-on. Search Tools averages 3,047. Developer Tools averages 1,585. If you are shipping an AI extension, the crowded category and the profitable category are not the same category.
Category coverage also thins out fast. Six of the 13 categories contain one or two add-ons each, together holding under 1.4% of users. Privacy and Security has exactly 2 AI entries, which is striking given how much of the AI-in-browser conversation is about privacy.
How Concentrated Is AI Add-on Usage on Firefox?
Extremely. One add-on, Grammarly: AI Writing and Grammar Checker App, holds 56.9% of all AI add-on daily users on Firefox. The top three hold 77.7%. The 79 add-ons ranked eleventh and below share 16.0% between them, which averages out to roughly 1,800 daily users each.
This is a winner-take-most market, and it changes how you should read any AI Firefox extension recommendation, including this one.
If a list tells you an add-on is “popular,” ask what that means numerically. On Firefox, an AI add-on with 5,000 daily users is in the top ten of its entire category. That is a real audience, but it is 1% of Grammarly: AI Writing and Grammar Checker App’s. The median add-on here has 1,572 users, and 31 of the 89 have fewer than 1,000.
The practical takeaway: outside the top three, you are choosing from small projects, often maintained by one developer. 86 distinct developers publish these 89 add-ons, so there is almost no consolidation. That is not a reason to avoid them. It is a reason to check the last-updated date and the review count before you install, which is exactly what the two sections below are for.
Do Star Ratings Help You Pick an AI Firefox Extension?
Barely. Ratings on Mozilla Add-ons are clustered so tightly that they cannot separate good from bad on their own: 52 of the 89 AI add-ons (58%) sit at 4.0 stars or above, and the unweighted average across the whole directory is 4.03 out of 5.
The bigger problem is thin review bases. 22 of the 89 add-ons carry fewer than 10 reviews, and 1 has none at all. eight add-ons show a perfect 5.0: the best-supported of those has 18 reviews, and the remaining seven run on fewer, down to 1. A 5.0 from four people tells you almost nothing.
Weighting by review count moves the average from 4.03 to 4.11, which confirms that the heavily reviewed add-ons are slightly better than the lightly reviewed ones, but not dramatically so. Across all 89 add-ons there are only 7,195 reviews in total, and Grammarly: AI Writing and Grammar Checker App holds 3,211 of them. Seven add-ons have 100 or more reviews. The other 82 are working with sample sizes a statistician would laugh at.
This is precisely why review volume gets its own 20% slice of the Quality Score rather than being folded into the rating. Rating tells you how people felt. Review count tells you whether to believe them.
One more absence worth naming: none of the 89 add-ons carry Mozilla’s Recommended badge. Mozilla awards that badge to extensions that pass additional human security and functionality review, and as of this snapshot not a single AI add-on has one. If you were hoping to use the Recommended filter as a safety shortcut for AI extensions, it does not currently help you.
Which AI Firefox Add-ons Are Growing Fastest?
Claude grew 75.8% over the 21 days to 7 August 2026, from 3,738 to 6,573 daily users, the fastest growth in the directory. Overall the market shrank: of the 87 add-ons present in both the first and last snapshot, 28 gained users and 57 lost them.
Mozilla does not publish historical daily-user counts, which is why nobody else can show you this. The only way to get it is to snapshot the API every day and keep the file, which is what we have been doing since 18 July 2026.
The fastest-growing AI Firefox add-ons:
| Add-on | Daily users 2026-07-18 | Daily users 2026-08-07 | Change | % change |
|---|---|---|---|---|
| Claude | 3,738 | 6,573 | +2,835 | +75.8% |
| ChatGPT in Sidebar | 1,506 | 2,028 | +522 | +34.7% |
| AI Chat Export | Export ChatGPT, Claude and others | 579 | 743 | +164 | +28.3% |
| ClaudeCodeBrowser | 1,179 | 1,417 | +238 | +20.2% |
| Janitor AI Scraper | 1,346 | 1,572 | +226 | +16.8% |
| Gemini | 2,803 | 3,265 | +462 | +16.5% |
| Claude Counter | 906 | 1,011 | +105 | +11.6% |
| Claude Chat Exporter | 608 | 676 | +68 | +11.2% |
four of the eight fastest risers are Claude-specific or Gemini-specific tools, and only one is ChatGPT-specific. That is a meaningful split in a directory where 43 of 89 add-ons are built around ChatGPT: the ChatGPT extension category is saturated and flat, while Claude and Gemini tooling is where new installs are going.
And the biggest losses in the same window:
| Add-on | Daily users 2026-07-18 | Daily users 2026-08-07 | Change | % change |
|---|---|---|---|---|
| Grammarly: AI Writing and Grammar Checker App | 523,381 | 502,948 | -20,433 | -3.9% |
| DeepL: AI translator and writing assistant | 167,195 | 157,006 | -10,189 | -6.1% |
| 划词翻译 | 28,283 | 26,686 | -1,597 | -5.6% |
| AI Side Bar Go | 7,447 | 6,880 | -567 | -7.6% |
| Copilot Launcher Button | 7,632 | 7,137 | -495 | -6.5% |
| WebChatGPT: ChatGPT with internet access | 7,450 | 7,048 | -402 | -5.4% |
Grammarly: AI Writing and Grammar Checker App shed 20,433 daily users, DeepL: AI translator and writing assistant 10,189. The incumbents that hold most of the audience both lost ground, which is what pulls the whole directory down 4.4% over the period. Read that carefully, though: a 3.9% decline on a half-million-user base is normal seasonal churn, not collapse. 21 days is a trend hint, not a verdict.
Which AI Firefox Add-ons Look Abandoned?
Sixteen add-ons with more than 1,000 daily users have not shipped an update in over 12 months. Browser APIs, AI provider endpoints, and site layouts all change; an AI extension that has not been touched in years is very likely partly broken, and it still holds your page-access permissions either way.
| Add-on | Last updated by its developer | Daily users | Rating |
|---|---|---|---|
| Export ChatGPT | 2022-12-17 | 1,667 | 2.4/5 |
| Chat GPT for Google | 2023-02-25 | 1,973 | 2.6/5 |
| ChatGPT Sidebar for Fire Fox | 2023-09-10 | 2,953 | 3.8/5 |
| Copilot Launcher Button | 2024-02-19 | 7,137 | 4.0/5 |
| Youtube ChatGPT summarization | 2024-04-27 | 1,482 | 3.1/5 |
| Bing AI for Firefox | 2024-05-01 | 1,384 | 3.8/5 |
| Gemini for Google | 2024-05-19 | 3,760 | 3.5/5 |
| 划词翻译 | 2024-08-12 | 26,686 | 4.3/5 |
| ChatGPT search | 2024-11-01 | 2,096 | 3.8/5 |
| Freespoke - AI Search Tool | 2024-12-18 | 4,130 | 4.7/5 |
| Copilot Sidebar | 2025-02-24 | 2,045 | 3.6/5 |
| WebChatGPT: ChatGPT with internet access | 2025-04-03 | 7,048 | 3.7/5 |
| Wordtune: AI Writing, Paraphrasing & Grammar Tool | 2025-04-09 | 1,331 | 3.4/5 |
| ChatGPT Ctrl+Enter Sender | 2025-05-18 | 1,599 | 4.6/5 |
| Youtube Transcript AI Summary | 2025-06-25 | 1,128 | 2.8/5 |
| Browser Control MCP | 2025-07-15 | 1,337 | 5.0/5 |
For context, 32 of the 89 add-ons shipped an update in the last 30 days and 44 in the last 90, so the healthy half of this directory is genuinely active. The oldest entry still listed was last updated in October 2021.
I would treat anything in that table as install-at-your-own-risk, and I would look hardest at the ones with big user counts and old dates. 划词翻译 has 26,686 daily users on a August 2024 build. Copilot Launcher Button has 7,137 users on a February 2024 build, which makes it the number 7 most-installed AI add-on on Firefox running code over 2 year old.
The check takes ten seconds: open the add-on’s Mozilla Add-ons page, look at “Last updated,” and if it is over a year old, read the recent reviews before installing.
Best AI Firefox Add-ons by Use Case
Rankings are useful, but nobody installs “the highest quality score.” They install a translator, or a summarizer, or something to stop losing their ChatGPT history. These groups are organised by the job you are trying to do, with each group sorted by quality score.
Best AI writing and grammar assistants
The highest-adoption tools for grammar, paraphrasing, and tone, which is the most-used AI category on Firefox by a wide margin.
| Add-on | Rating | Daily users | Quality score |
|---|---|---|---|
| Grammarly: AI Writing and Grammar Checker App | 4.1/5 (3,211) | 502,948 | 94/100 |
| DeepL: AI translator and writing assistant | 4.2/5 (1,028) | 157,006 | 84/100 |
| Wordtune: AI Writing, Paraphrasing & Grammar Tool | 3.4/5 (14) | 1,331 | 37/100 |
| Grammar Checker and Writing Assistant by Sapling | 3.8/5 (28) | 692 | 37/100 |
Best AI chatbot sidebars
Bring ChatGPT, Claude, Gemini, or Copilot into a sidebar so you can ask AI about the page you are on without switching tabs.
| Add-on | Rating | Daily users | Quality score |
|---|---|---|---|
| AI Side Bar Go | 4.3/5 (23) | 6,880 | 55/100 |
| ChatGPTBox | 4.4/5 (98) | 2,199 | 52/100 |
| ChatGPT in Sidebar | 4.1/5 (14) | 5,956 | 51/100 |
| Voila - AI Assistant, Copilot and AI Writer | 4.2/5 (30) | 2,894 | 49/100 |
| Copilot Sidebar | 3.6/5 (11) | 2,045 | 41/100 |
Best AI translators
Inline, AI-powered translation for web pages, PDFs, subtitles, and manga, side by side with the original text.
| Add-on | Rating | Daily users | Quality score |
|---|---|---|---|
| DeepL: AI translator and writing assistant | 4.2/5 (1,028) | 157,006 | 84/100 |
| 划词翻译 | 4.3/5 (335) | 26,686 | 70/100 |
| AI Subtitles & Immersive Translate - Trancy | 4.0/5 (62) | 4,870 | 53/100 |
| Dual Subtitles & AI Translation - InterSub | 3.9/5 (20) | 1,332 | 41/100 |
| TransorAI - AI Translator | Web, PDF, Images | 4.8/5 (5) | 668 | 40/100 |
| NextAI Translator | 2.6/5 (25) | 509 | 26/100 |
Best AI summarizers for YouTube, web, and PDF
Feed these a video, article, or PDF and get the key points back in seconds instead of reading or watching the whole thing.
| Add-on | Rating | Daily users | Quality score |
|---|---|---|---|
| YouTube to NotebookLM - YouTube to Gemini Notebook | 4.6/5 (17) | 3,918 | 53/100 |
| Clarify AI: YouTube Summaries | 4.3/5 (90) | 814 | 44/100 |
| YouTube Summary with ChatGPT & Claude | 2.5/5 (30) | 4,573 | 40/100 |
| Youtube Transcript AI Summary | 2.8/5 (26) | 1,128 | 33/100 |
| Mapify - AI Mind Map and Youtube Summary | 3.5/5 (2) | 885 | 31/100 |
Best AI chat exporters and savers
Save, back up, and share your ChatGPT, Claude, and Gemini conversations as PDF, Markdown, or a synced note.
| Add-on | Rating | Daily users | Quality score |
|---|---|---|---|
| ChatGPT to PDF | 4.5/5 (51) | 9,344 | 60/100 |
| ChatGPT Export | 4.3/5 (36) | 3,518 | 52/100 |
| Claude Exporter | 3.6/5 (12) | 1,795 | 40/100 |
| Save my Chatbot - AI Conversation Exporter | 3.9/5 (29) | 697 | 38/100 |
| AI Chat Exporter | 3.4/5 (7) | 638 | 31/100 |
| IdeaPi: Chat Exporter for ChatGPT, Gemini & Claude | 3.2/5 (4) | 691 | 29/100 |
Best ChatGPT power-user add-ons
Extensions that upgrade the AI chat interface itself: web access, prompt libraries, folders, and speed fixes for long chats.
| Add-on | Rating | Daily users | Quality score |
|---|---|---|---|
| WebChatGPT: ChatGPT with internet access | 3.7/5 (107) | 7,048 | 54/100 |
| Speed Booster for ChatGPT - Fix Lag & Export | 4.4/5 (44) | 3,324 | 52/100 |
| Superpower ChatGPT | 3.4/5 (132) | 1,563 | 43/100 |
| AI Prompt Genius | 3.0/5 (20) | 893 | 32/100 |
Best AI extensions for developers
Local-model UIs, code discovery, and browser automation built for people who work in the console as much as the browser.
| Add-on | Rating | Daily users | Quality score |
|---|---|---|---|
| Page Assist - A Web UI for Local AI Models | 4.7/5 (76) | 8,673 | 62/100 |
| chessvision.ai Chess Position Scanner | 4.8/5 (79) | 4,234 | 58/100 |
| Browser Control MCP | 5.0/5 (6) | 1,337 | 46/100 |
| AI Code Finder & Alerts for Papers: CatalyzeX | 4.8/5 (20) | 850 | 44/100 |
The Full Directory: All 89 AI Firefox Add-ons Ranked
Every AI Firefox extension in this build, ranked by Quality Score, with the raw inputs shown so you can check the maths yourself. Rating is out of 5, reviews is the count behind that rating, daily users is AMO’s average_daily_users, and last updated is the developer’s most recent release.
| # | AI Firefox add-on | Developer | Category | Rating | Reviews | Daily users | Quality score | Last updated |
|---|---|---|---|---|---|---|---|---|
| 1 | Grammarly: AI Writing and Grammar Checker App | Grammarly | Language & Translation | 4.1 | 3,211 | 502,948 | 94 | 2026-04-24 |
| 2 | DeepL: AI translator and writing assistant | DeepL | Language & Translation | 4.2 | 1,028 | 157,006 | 84 | 2026-07-10 |
| 3 | 划词翻译 | 划词翻译 | Language & Translation | 4.3 | 335 | 26,686 | 70 | 2024-08-12 |
| 4 | Page Assist - A Web UI for Local AI Models | Muhammed Nazeem | Other | 4.7 | 76 | 8,673 | 62 | 2026-08-05 |
| 5 | Simplify Copilot - Autofill job applications | Simplify | Other | 4.2 | 144 | 9,562 | 61 | 2026-08-03 |
| 6 | ChatGPT to PDF | PDFCrowd | Other | 4.5 | 51 | 9,344 | 60 | 2026-07-17 |
| 7 | chessvision.ai Chess Position Scanner | Pawel Kacprzak | Games & Entertainment | 4.8 | 79 | 4,234 | 58 | 2026-04-08 |
| 8 | Definer: Word Translator, Ask AI, Popup Dictionary | Lumetrium | Search Tools | 4.6 | 144 | 3,398 | 57 | 2026-07-08 |
| 9 | AI Side Bar Go | Landy | Search Tools | 4.3 | 23 | 6,880 | 55 | 2026-07-13 |
| 10 | Freespoke - AI Search Tool | Freespoke.com | Search Tools | 4.7 | 45 | 4,130 | 55 | 2024-12-18 |
| 11 | AI Toolbox | Arash Yoosefdoost | Search Tools | 4.6 | 52 | 3,789 | 55 | 2026-02-25 |
| 12 | Claude Usage Tracker | lugia19 | Appearance | 4.9 | 34 | 3,474 | 55 | 2026-08-01 |
| 13 | Complexity | Perplexity AI Supercharged | Duong Pham Ngoc | News & Blogging | 4.8 | 48 | 2,993 | 55 | 2026-06-20 |
| 14 | WebChatGPT: ChatGPT with internet access | Extensions Hub | Search Tools | 3.7 | 107 | 7,048 | 54 | 2025-04-03 |
| 15 | AI Subtitles & Immersive Translate - Trancy | Trancy | Language & Translation | 4.0 | 62 | 4,870 | 53 | 2026-08-04 |
| 16 | YouTube to NotebookLM - YouTube to Gemini Notebook | Dima | News & Blogging | 4.6 | 17 | 3,918 | 53 | 2026-08-03 |
| 17 | Gemini | AI Allstar | Search Tools | 4.8 | 15 | 3,265 | 53 | 2026-05-30 |
| 18 | Copilot Launcher Button | SYS64738 | Search Tools | 4.0 | 18 | 7,137 | 52 | 2024-02-19 |
| 19 | AI Exporter - Gemini to PDF & Sync to Notion | Colin | Download Management | 4.1 | 43 | 3,972 | 52 | 2026-05-26 |
| 20 | ChatGPT Export | Enes Saltik | Social & Communication | 4.3 | 36 | 3,518 | 52 | 2026-06-28 |
| 21 | Speed Booster for ChatGPT - Fix Lag & Export | BGSN | Developer Tools | 4.4 | 44 | 3,324 | 52 | 2026-08-05 |
| 22 | Gemini Voyager | Nagi-ovo | Developer Tools | 4.8 | 16 | 3,297 | 52 | 2026-07-31 |
| 23 | ChatGPTBox | josStorer | Search Tools | 4.4 | 98 | 2,199 | 52 | 2026-06-29 |
| 24 | ChatGPT in Sidebar | semanticdata | Search Tools | 4.1 | 14 | 5,956 | 51 | 2025-09-05 |
| 25 | ChatGPT in Sidebar | All In AI | Appearance | 5.0 | 18 | 2,028 | 51 | 2026-05-20 |
| 26 | Claude | Claude Search | Other | 3.9 | 11 | 6,573 | 50 | 2026-06-15 |
| 27 | ChatGPT Reader & Transcriber: Free AI Text↔Speech | Democratic Developer | Language & Translation | 3.9 | 40 | 3,724 | 50 | 2026-07-29 |
| 28 | AI Anywhere for ChatGPT | Juraj Mäsiar | Search Tools | 4.6 | 38 | 1,862 | 50 | 2026-02-27 |
| 29 | Summarize and Translate with Gemini | Sadao Hiratsuka | Language & Translation | 4.6 | 46 | 1,679 | 50 | 2026-08-02 |
| 30 | Voila - AI Assistant, Copilot and AI Writer | Browser extensions | News & Blogging | 4.2 | 30 | 2,894 | 49 | 2025-10-16 |
| 31 | ChatGPT Bulk Delete | User_425 | Other | 4.8 | 13 | 1,596 | 48 | 2026-05-16 |
| 32 | Google Reader: Free Natural AI Text to Speech, TTS | Democratic Developer | Other | 4.7 | 15 | 1,636 | 47 | 2026-07-29 |
| 33 | Pinned ChatGPT | ChatGPT | Tabs | 4.5 | 31 | 1,547 | 47 | 2026-03-11 |
| 34 | Torii Image Translator - AI Manga Translator | stringie | Language & Translation | 3.6 | 77 | 2,439 | 46 | 2026-08-01 |
| 35 | LightSession Pro for ChatGPT | Emil K | Developer Tools | 4.2 | 23 | 2,121 | 46 | 2026-04-09 |
| 36 | ChatGPT Ctrl+Enter Sender | masachika.kmd | Appearance | 4.6 | 14 | 1,599 | 46 | 2025-05-18 |
| 37 | Ai Chat everywhere | khashayar | Search Tools | 4.1 | 61 | 1,500 | 46 | 2026-07-04 |
| 38 | Browser Control MCP | EyalZ | Search Tools | 5.0 | 6 | 1,337 | 46 | 2025-07-15 |
| 39 | Gemini for Google | tudoujun | Search Tools | 3.5 | 17 | 3,760 | 45 | 2024-05-19 |
| 40 | ChatGPT Sidebar for Fire Fox | HamzaDev | Developer Tools | 3.8 | 21 | 2,953 | 45 | 2023-09-10 |
| 41 | Janitor AI Scraper | Weary Galaxy | Other | 4.3 | 23 | 1,572 | 45 | 2026-06-20 |
| 42 | AI answer in Google | OptiSearch | Developer Tools | 4.0 | 53 | 1,311 | 44 | 2026-01-11 |
| 43 | AI Detector for text and images - Winston AI | Winston AI | News & Blogging | 4.4 | 35 | 1,061 | 44 | 2026-07-22 |
| 44 | Claude Counter | pauljones0 | Developer Tools | 5.0 | 4 | 1,011 | 44 | 2026-03-20 |
| 45 | RTL All Fixer (Right To Left Fixer) | Dr.FATAL | News & Blogging | 5.0 | 7 | 925 | 44 | 2025-01-30 |
| 46 | AI Code Finder & Alerts for Papers: CatalyzeX | CatalyzeX | Developer Tools | 4.8 | 20 | 850 | 44 | 2025-05-03 |
| 47 | Clarify AI: YouTube Summaries | Clarify AI | News & Blogging | 4.3 | 90 | 814 | 44 | 2026-08-01 |
| 48 | ChatGPT search | ars3nb | Search Tools | 3.8 | 20 | 2,096 | 43 | 2024-11-01 |
| 49 | Claude Usage & Fable 5 Limit Tracker - UsageMeter | Pilote Code | Developer Tools | 4.3 | 6 | 1,790 | 43 | 2026-07-19 |
| 50 | Superpower ChatGPT | Saeed Ezzati | Search Tools | 3.4 | 132 | 1,563 | 43 | 2026-08-05 |
| 51 | Duck.ai Chat on Sidebar | Koala Yeung | Privacy & Security | 4.9 | 8 | 888 | 43 | 2026-02-28 |
| 52 | ChatGPT Timestamp | Yiwei Dai | Developer Tools | 5.0 | 9 | 721 | 43 | 2026-03-15 |
| 53 | Bing AI for Firefox | Patrik Martinko | Search Tools | 3.8 | 41 | 1,384 | 42 | 2024-05-01 |
| 54 | Save ChatGPT as PDF | AI Power | Photos, Music & Video | 4.5 | 17 | 770 | 42 | 2026-01-24 |
| 55 | Copilot Sidebar | Yashjit | Search Tools | 3.6 | 11 | 2,045 | 41 | 2025-02-24 |
| 56 | Dual Subtitles & AI Translation - InterSub | InterSub | Appearance | 3.9 | 20 | 1,332 | 41 | 2026-07-01 |
| 57 | NotebookLM Tools for Gemini Notebook™ | trungpv | News & Blogging | 5.0 | 2 | 852 | 41 | 2026-07-29 |
| 58 | YouTube Summary with ChatGPT & Claude | Glasp | News & Blogging | 2.5 | 30 | 4,573 | 40 | 2026-08-05 |
| 59 | Claude Exporter | agoramachina | Download Management | 3.6 | 12 | 1,795 | 40 | 2026-05-19 |
| 60 | Gemini next to Google results | OptiSearch | Developer Tools | 3.9 | 36 | 964 | 40 | 2026-01-11 |
| 61 | AI Chat Export | Export ChatGPT, Claude and others | Covai Labs | Developer Tools | 4.8 | 5 | 743 | 40 | 2026-08-06 |
| 62 | TransorAI - AI Translator | Web, PDF, Images | Transor AI | Language & Translation | 4.8 | 5 | 668 | 40 | 2025-12-05 |
| 63 | Youtube ChatGPT summarization | ai fan | News & Blogging | 3.1 | 83 | 1,482 | 39 | 2024-04-27 |
| 64 | Claude Helper | Mert | Download Management | 5.0 | 2 | 571 | 39 | 2024-07-24 |
| 65 | Save my Chatbot - AI Conversation Exporter | Hugo COLLIN | Download Management | 3.9 | 29 | 697 | 38 | 2025-11-20 |
| 66 | Wordtune: AI Writing, Paraphrasing & Grammar Tool | AI21 | Language & Translation | 3.4 | 14 | 1,331 | 37 | 2025-04-09 |
| 67 | Tailwind - AI marketing content assistant | Tailwind | News & Blogging | 3.9 | 16 | 770 | 37 | 2021-10-22 |
| 68 | Grammar Checker and Writing Assistant by Sapling | Sapling.ai | Language & Translation | 3.8 | 28 | 692 | 37 | 2026-08-04 |
| 69 | editGPT | jiconaar | Language & Translation | 4.2 | 17 | 538 | 37 | 2025-11-07 |
| 70 | Fydub: YouTube Translator with AI Voice Dubbing | Daniel Perlera | Language & Translation | 5.0 | 1 | 519 | 37 | 2026-08-03 |
| 71 | Claude Chat Exporter | sylvester1979 | Developer Tools | 4.1 | 8 | 676 | 36 | 2026-03-19 |
| 72 | Claude QoL | lugia19 | Appearance | 4.1 | 7 | 535 | 35 | 2026-08-05 |
| 73 | Chat GPT for Google | Chat GPT for Google | Developer Tools | 2.6 | 14 | 1,973 | 34 | 2023-02-25 |
| 74 | AI Chat WEB3.0 - ChatGPT 4.1 | AI Chat WEB3.0 | Other | 3.3 | 12 | 975 | 34 | 2025-07-27 |
| 75 | Export ChatGPT | Mohalobaidi | Appearance | 2.4 | 37 | 1,667 | 33 | 2022-12-17 |
| 76 | Youtube Transcript AI Summary | RSpark | Other | 2.8 | 26 | 1,128 | 33 | 2025-06-25 |
| 77 | AI Prompt Genius | bennyfi4 | Other | 3.0 | 20 | 893 | 32 | 2026-07-29 |
| 78 | SayAI - Audio for ChatGPT | Nodetics | Search Tools | 3.5 | 16 | 572 | 32 | 2024-11-29 |
| 79 | Mapify - AI Mind Map and Youtube Summary | XMIND LIMITED | Other | 3.5 | 2 | 885 | 31 | 2026-03-19 |
| 80 | Comic Translator - Manga translator using AI | liquiddev99 | Language & Translation | 3.5 | 4 | 750 | 31 | 2026-08-05 |
| 81 | Claude in Sidebar | Jadon Mason | Appearance | 3.3 | 7 | 726 | 31 | 2026-07-13 |
| 82 | AI Chat Exporter | Hamza | Bookmarks | 3.4 | 7 | 638 | 31 | 2026-07-20 |
| 83 | YourAIScroll - AI Chat History Exporter | Kareverie | Developer Tools | 3.3 | 13 | 628 | 31 | 2026-07-26 |
| 84 | IdeaPi: Chat Exporter for ChatGPT, Gemini & Claude | IdeaPi.ai | News & Blogging | 3.2 | 4 | 691 | 29 | 2026-04-18 |
| 85 | DeniedPixels | DeniedPixels | Privacy & Security | 3.1 | 7 | 542 | 28 | 2026-08-01 |
| 86 | NextAI Translator | yetone | Search Tools | 2.6 | 25 | 509 | 26 | 2023-12-19 |
| 87 | Madomi - Manga Translator | Pawaka Labs | Other | 2.7 | 7 | 558 | 25 | 2026-08-03 |
| 88 | ChatGPT for Gmail | Dolevf | Search Tools | 3.0 | 2 | 520 | 24 | 2023-03-16 |
| 89 | ClaudeCodeBrowser | nanogenomic | Developer Tools | n/a | 0 | 1,417 | 7 | 2025-12-16 |
How Do You Install an AI Firefox Add-on?
Open the add-on’s Mozilla Add-ons link from the table above, click “Add to Firefox,” then confirm the permissions prompt. The extension’s icon appears in your toolbar, where you can right-click to pin or manage it. Most AI sidebar and assistant add-ons then work straight away from that button or a right-click menu.
Before you confirm that permissions prompt, read it. Nearly every AI assistant asks for permission to read and change data on the pages you visit, because that is genuinely how it works: it cannot summarize a page it cannot see. That is not automatically a red flag, but it does mean an AI extension is one of the most privileged things you can install in a browser.
My install checklist, in order:
- Check the last-updated date. Over 12 months old and I do not install it. That rule alone removes 24 of the 89 add-ons on this page.
- Check the review count, not just the rating. Under 10 reviews means the rating is noise. Prefer add-ons with an established base.
- Read the permissions prompt. If a tool that only reformats one website asks for access to all sites, close the tab.
- Prefer a local model if the content is sensitive. Page Assist exists precisely so your prompts can stay on your machine.
- Install one at a time. Two AI sidebars fighting over the same keyboard shortcut is a bad afternoon.
Are AI Firefox extensions free? Nearly all install at no cost from Mozilla Add-ons. Most then run a freemium model: core features are free, and heavier usage such as higher limits or premium models needs a paid plan the add-on itself sells. Pricing changes independently of this directory, so check the add-on’s own listing for current numbers.
What This Data Says About AI on Firefox
Five conclusions I would stand behind, all of them falsifiable from the tables above:
- AI on Firefox is a translation and writing story, not a chatbot story. 79.7% of usage sits in one category, and it is not the one developers are building for.
- The market is a monopoly with a long tail. One add-on at 56.9%, then 79 add-ons sharing 16.0%.
- Ratings are close to useless as a filter here, with 58% of add-ons above 4.0 and 22 carrying fewer than 10 reviews.
- Claude and Gemini tooling is where the growth is. four of the eight fastest risers, against one ChatGPT-specific add-on, despite ChatGPT tools being 48% of the directory.
- Maintenance is the real risk, not quality. Sixteen add-ons with real user bases are running code over a year old, and no AI add-on has Mozilla’s Recommended badge to fall back on.
“The most useful thing about ranking add-ons on public data instead of opinion is how often it embarrasses the consensus. Every roundup I read said AI browsing on Firefox was about ChatGPT sidebars. The install numbers say it is about Grammarly and DeepL, and the growth numbers say the next wave is Claude. You only see that if you commit to the same formula for every entry and then publish the formula.”
Alston Antony, founder of zplatform.ai and Senior Digital Marketing Manager at Brainstorm Force
If you also run Chrome, our AI Chrome extensions leaderboard is scored on the identical formula, so you can compare the two ecosystems directly. To add AI inside your own site rather than your browser, start with the best AI WordPress plugins. For AI that plugs into your coding tools instead, see our ranked MCP servers directory. And for more data-backed roundups like this one, browse the full set of best AI tools lists.
Frequently Asked Questions
What is the best AI extension for Firefox?
By combined adoption, rating, and review volume, Grammarly is the best AI extension for Firefox with a quality score of 94/100 and 502,948 daily active users. For translation specifically, DeepL scores 84/100. For private, local AI, Page Assist scores 62/100 and keeps your prompts on your own machine.
Are AI Firefox extensions safe to install?
Safety depends on the add-on’s permissions and its developer, not on it being AI. Mozilla reviews add-ons before listing them, but you should still read the permissions prompt, prefer add-ons with a large established review base, and avoid anything not updated in over a year. Note that none of the 89 AI add-ons currently hold Mozilla’s Recommended badge.
How many AI add-ons are there for Firefox?
There are 89 genuine AI add-ons on Mozilla Add-ons as of 7 August 2026, holding 883,480 combined daily active users. That count applies a strict AI-only rule: extensions that merely mention AI in passing, and extensions built to block AI features, are excluded by hand.
Why is my favourite Firefox add-on not on this list?
This is an AI-only directory. Ad blockers, password managers, VPNs, and screenshot tools are excluded even when their store copy mentions AI, and so are extensions whose purpose is to remove AI features. If an add-on is genuinely AI-first and missing, it most likely fell outside the AMO search terms this build uses.
How often is this AI Firefox add-ons list updated?
The underlying dataset is rebuilt from the Mozilla Add-ons API and republished here, with the snapshot date shown at the top of the page. Daily user counts have been captured every day since 18 July 2026, which is what makes the growth and decline figures in this report possible.
Methodology and How to Cite This Data
Source: Mozilla Add-ons (AMO) public API v5, plus 21 first-party daily snapshots of user counts taken between 18 July 2026 and 7 August 2026.
Sample: 89 AI-first Firefox extensions, 883,480 combined daily active users, 7,195 reviews, 86 distinct developers, 13 Mozilla categories.
Ranking formula: Quality Score = 45% adoption (log of average daily active users, normalized 0 to 100 across the dataset) + 35% rating score (rating out of 5, scaled to 100) + 20% trust score (log of review count, normalized 0 to 100 across the dataset).
Inclusion: AI-first only. An add-on is listed when an AI term appears in its name, or a specific AI product such as ChatGPT, Claude, or Gemini appears in its description. Anti-AI utilities and incidental AI mentions are removed by hand.
Not measured: Security. Mozilla publishes no per-add-on vulnerability feed, so no security score is computed. Last-updated dates are passed through from AMO unmodified.
No paid placement: No add-on paid for inclusion, position, or a higher score. Ranking is entirely formula-driven from public metrics, which you can verify against any add-on’s Mozilla Add-ons listing.
Cite as: zplatform.ai, “Best AI Firefox Add-ons (Extensions): Real Usage Numbers Report,” data snapshot 7 August 2026.
Every figure on this page is drawn from the tables above, so if you quote a number you can point a reader at the row it came from. That is the whole point of publishing the formula alongside the ranking: the best AI Firefox extensions for you depend on the job you need done, and you should be able to check my working rather than take my word for it.
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