Every Chrome extension expands the code and permissions running beside email, documents and logged-in websites. Installing ten overlapping AI sidebars is a poor trade. For most people, only two extensions earn permanent access: Grammarly for writing and Perplexity’s official companion for source-aware research. Glasp is the optional third for people who actively annotate articles and YouTube transcripts.
The short list
| Extension | Keep it for | Useful free entry | Main reason to skip |
|---|---|---|---|
| Grammarly | Grammar, clarity and tone while typing | Core corrections and some AI assistance | Handles page content and communications to provide suggestions |
| Perplexity AI Companion | Summarizing and questioning the current page with sources | Basic companion/search access | Another research interface is redundant if the web app is enough |
| Glasp | Highlighting, annotating and summarizing web/YouTube research | Core annotation workflow | Creates a separate knowledge silo unless used consistently |
Prices and limits change. Install from the verified publisher listing in the Chrome Web Store, not an advertisement or similarly named clone. Review the current privacy disclosure and requested permissions before enabling it.
1. Grammarly: the one extension most writers will use daily
Grammarly for Chrome provides spelling, punctuation, grammar, clarity and tone suggestions in Gmail, Google Docs, LinkedIn and many other text fields. The extension’s 2026 listing also includes generative drafting and rewriting capabilities, with deeper rewrites, style and team controls in paid offerings. It is far more useful than an AI sidebar that waits for a prompt because it appears where writing happens.
Where it saves time
Use Grammarly for outbound email, proposals, support responses and form entries. It catches missing words, accidental tone and unclear sentences before they leave the browser. The explanation behind a suggestion is often more valuable than accepting the replacement.
Set the correct English variant and add product names to the dictionary. Business users should configure style guidance rather than relying on generic preferences. A legal, technical or brand-approved phrase may intentionally break a broad style rule.
Where it fails
Grammarly is an English-first editor, even as its multilingual features evolve. It cannot verify a factual claim, contract commitment, citation or recipient. A polished sentence can still be wrong. Generative rewrites may alter degree, negation or obligation, so compare the original.
The Chrome Web Store disclosure says the extension handles categories including personal communications, website content and user activity. That access is understandable for an inline editor but material for confidential work. Organizations should use approved plans and administrative policies, and users should disable the extension on sensitive sites if policy requires.
Best configuration
Turn off automatic acceptance and keep suggestions visible. Disable generative prompts if only proofreading is needed. Review site access in Chrome’s extension settings, remove unnecessary incognito permission and pause it for privileged admin, health, legal or financial portals.
Install it if: you write substantial English in the browser and will review suggestions rather than accept them blindly.
2. Perplexity AI Companion: the research extension
Perplexity’s browser companion lets users ask questions about the current page, summarize it and conduct web-grounded research without repeatedly copying text into another tab. Its value is not the summary itself; it is the ability to follow sources and ask a targeted question while preserving page context.
Where it saves time
Use it to orient yourself in a long policy, product documentation page or industry report. Ask for the main claims, stated limitations and terms requiring verification. For a product comparison, use the companion to locate official pricing or feature documentation, then open those sources.
It is also useful for unfamiliar terminology. A question such as “explain this paragraph and identify which claim comes from an external source” is more productive than “summarize everything.”
Where it fails
A citation link does not guarantee faithful interpretation. The cited page may be outdated, low quality or irrelevant to the sentence. Open the source, check its publication date and distinguish the vendor’s claim from independent evidence.
Summaries can omit tables, footnotes, interactive elements or content behind a login. Never use a browser assistant to make medical, legal or financial decisions without authoritative review. If the Perplexity web app or an organization’s approved AI already handles research, the extension may add little.
Best configuration
Grant access only where needed rather than automatically on every site if Chrome and the extension support that control. Do not run it on customer portals or confidential dashboards unless the organization has approved the data handling. Clear history and connected services according to policy.
Install it if: you research the open web several times a day and routinely inspect original sources.
3. Glasp: optional for active web annotators
Glasp is a web-highlighting and social annotation tool with AI-assisted summary and knowledge features. It can capture highlighted passages from articles and transcripts, organize them with tags and move research toward a personal knowledge workflow. Its YouTube transcript support is helpful for lectures, interviews and product demonstrations.
Where it saves time
Instead of saving an unread bookmark, highlight the specific evidence, write a note about why it matters and export or sync it to the chosen knowledge system. For a video, inspect the transcript, jump to relevant timestamps and preserve selected passages with the source URL.
Glasp earns its place only when annotation is a practiced workflow. A writer who publishes research-backed work every week may build a valuable source library. A casual user simply creates another inbox of highlights.
Where it fails
AI summaries can flatten nuance and are no substitute for watching the source context. Transcript accuracy varies with audio, names and accents. Highlights may contain copyrighted or confidential material, and social features can expose activity the user expected to be private. Review privacy and visibility settings.
Install it if: you consistently convert web and video research into cited notes. Otherwise, use browser bookmarks or the web clipper in your existing notes app.
Why the other AI extensions stay uninstalled
All-in-one assistants such as Monica, Sider, HARPA AI and Merlin can offer chat, summaries, translations and writing across pages. They may be useful for a particular workflow, but their features overlap heavily with ChatGPT, Claude, Gemini, Perplexity and built-in browser capabilities. The deciding question is not which has the longest toolbar; it is which publisher, permissions, model, retention terms and workflow the user can govern.
Extensions that inject into every page can see more context than a web app opened intentionally. Free products may rely on restrictive quotas, upsells or changing providers. Avoid extensions that request broad permissions without a clear need, have a recently changed publisher, imitate a famous brand or lack a credible privacy policy.
A five-minute security review
Open chrome://extensions, select Details and inspect site access, incognito access and file URL access. Choose “on click” or selected sites when continuous access is unnecessary. Remove extensions not used in the last month.
On the Chrome Web Store listing, verify the developer, website, update date, privacy disclosure and user base. Reviews can expose recent breakage but do not prove safety. Enterprise users should follow the browser allowlist and data-loss-prevention policy rather than self-install.
Use a separate browser profile for privileged administration and keep AI extensions out of it. Multi-factor authentication does not prevent an authorized extension from reading page content. Never paste secrets, recovery codes or customer data into an AI prompt.
A one-week usefulness test
Install one extension at a time. Record the specific action it replaces and minutes saved. Count incorrect suggestions, source-checking time and interruptions. At week’s end, keep it only if it supported at least three real tasks and did not duplicate an existing tool.
For Grammarly, test ten emails and one document. For Perplexity, test five research questions and verify every cited claim. For Glasp, confirm that highlights actually reach the note system and are reused in published work.
Verdict
Grammarly is the best general-purpose AI Chrome extension because it improves writing at the point of composition. Perplexity AI Companion is the second choice for users who conduct source-based web research. Glasp is worth adding only for disciplined web and video annotation.
Our pick: install Grammarly and Perplexity; stop at two. Add Glasp only when highlighting and transcript capture already form part of a repeatable research process. A smaller extension set is easier to trust, maintain and remember to use.