Best AI Chrome Extensions (2026)
AI extensions do four different jobs — answering, summarising, writing and archiving — and most disappointment comes from asking one tool to do all four. These eight are grouped by the job they actually do well, with ratings synced from the Chrome Web Store.
How we picked
- • Does one job well rather than everything vaguely
- • Free tier usable at real daily volume, not just for a demo
- • Clear about what page data leaves your device
- • Shows sources where the answer needs verifying
- • Actively updated against a fast-moving model landscape
At a glance
| # | Extension | Best for | Rating | Users | Pricing |
|---|---|---|---|---|---|
| 1 | Monica AI | An all-round AI sidekick | 4.9 | 3M+ | Freemium |
| 2 | Merlin AI | Summaries and research | 4.8 | 900K+ | Freemium |
| 3 | Perplexity | Answers you need to verify | 3.8 | 400K+ | Freemium |
| 4 | Grammarly | Everyday writing polish | 4.5 | 36M+ | Freemium |
| 5 | Wordtune | Rephrasing and tone | 4.6 | 1M+ | Freemium |
| 6 | YouTube Summary with ChatGPT | Skipping to the useful part of a video | 4.3 | 1M+ | Free |
| 7 | Scholarcy | Reading papers faster | 4.0 | 80K+ | Freemium |
| 8 | Glasp | Building a reading archive | 4.5 | 500K+ | Free |
Ratings and install counts are synced daily from each extension's Chrome Web Store listing.
1. Monica AI
One sidebar for chat, summarising, translating and rewriting on whatever page you are on, with a choice of underlying models.
Best for: An all-round AI sidekick
4.9~3M+ usersFreemium2. Merlin AI
Condenses long pages, videos and PDFs, then answers follow-up questions in the same panel instead of a separate tab.
Best for: Summaries and research
4.8~900K+ usersFreemium3. Perplexity
Every claim comes with clickable sources, which is the difference between something you can cite and something you merely hope is right.
Best for: Answers you need to verify
3.8~400K+ usersFreemium4. Grammarly
Grammar, clarity and tone suggestions in place, in almost every text field — correction rather than rewriting.
Best for: Everyday writing polish
4.5~36M+ usersFreemium5. Wordtune
Restates a sentence several ways so you can pick the register you meant, which is what you want when the meaning is already right.
Best for: Rephrasing and tone
4.6~1M+ usersFreemium6. YouTube Summary with ChatGPT
Turns a long talk into a timestamped outline you can scan, then jumps you to the section that matters.
Best for: Skipping to the useful part of a video
4.3~1M+ usersFree7. Scholarcy
Breaks an academic PDF into claims, methods and references so you can judge relevance before committing an hour.
Best for: Reading papers faster
4.0~80K+ usersFreemium8. Glasp
Saves highlights with AI summaries in one searchable place, so the reading you did last month is still usable.
Best for: Building a reading archive
4.5~500K+ usersFree
What to know before choosing
AI extensions do four distinct jobs: answering, summarising, writing and archiving. Most frustration comes from asking one tool to cover all four. Pick by the job you actually repeat.
If the work is answering questions about the page in front of you, a sidebar assistant such as Monica or Merlin fits — the page is already the context, so nothing gets copy-pasted. If the answer will end up in a document someone else checks, prefer a tool that shows sources. Summarisers still drop caveats and occasionally invert a conclusion on dense material, and citations are how you catch that.
For writing, separate correction from rewriting. Grammarly fixes grammar, clarity and tone in place, which is what you want in email and forms. Wordtune restates a sentence several ways, which is what you want when the meaning is right but the register is wrong. Together they cover most drafting; either alone leaves an obvious gap.
Research is the quiet win. A video summariser turns a forty-minute talk into something scannable, Scholarcy reduces a paper to claims and methods, and Glasp keeps highlights with summaries so old reading stays retrievable.
Two cautions. These extensions see the pages you use them on, so check what leaves your machine before pointing one at client or patient data, and read the data-use terms of the tier you are actually on. And free quotas are the real differentiator: several of these are delightful for a week and metered after that, so test with your genuine daily volume before paying.
Compare the shortlist head-to-head
Narrowed it to two? These side-by-side comparisons settle it with a feature table and a verdict.
Alternatives to the top picks
Frequently asked questions
Which AI extension is best if I only install one?
An all-round sidebar such as Monica, because it covers chat, summarising, translating and rewriting on any page. If your work depends on being able to verify answers, choose a cited-answer tool like Perplexity instead.
Are AI Chrome extensions safe to use with confidential work?
Assume the page content you act on is sent to a model provider. That is fine for public research and a problem for client, medical or internal data. Read the data-use terms of your tier, and prefer tools that let you switch off automatic page reading.
Do these extensions need a paid ChatGPT or Claude subscription?
Usually not — most bundle model access into their own free and paid tiers. The catch is quota: free tiers are generous for occasional use and metered quickly once you rely on them daily.
Can AI extensions summarise YouTube videos and PDFs?
Yes. Dedicated summarisers pull the transcript and produce a timestamped outline, and several assistants read PDFs opened in the browser. Accuracy drops on poor auto-captions and on scanned PDFs with no text layer.
Will an AI writing extension work inside Gmail and Google Docs?
Grammarly and Wordtune both work in Gmail and most rich text fields. Google Docs support is more limited and sometimes lags behind editor changes, so check the current store listing rather than an older review.