Grammarly: AI Writing and Grammar Checker App

Name: Grammarly: AI Writing and Grammar Checker App
Rating: 4.0917 (3207 reviews)
Author: Grammarly

From blank page to polished draft, Grammarly’s AI helps you write faster and stronger. Get real-time grammar fixes, tone transformations, and instant content generation right where you write in Firefox.

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Features & Capabilities

Grammarly for Firefox is an always-on AI writing assistant that helps you write faster and with greater confidence. It provides real-time grammar, spelling, and punctuation corrections, suggests clarity and tone improvements, and can generate one-click drafts to overcome writer’s block. Integrated directly into your browser, Grammarly works across Google Docs, Gmail, LinkedIn, and hundreds of thousands of other sites so you can improve text wherever you write.

Free users get essential grammar and clarity suggestions plus basic AI drafting and auto-citations, while Pro users unlock advanced sentence rewrites, tone and formality control, audience insights, plagiarism detection, and team style features. Backed by privacy and trust commitments, Grammarly also offers desktop apps and a dedicated Docs writing surface for deeper composition and strategic feedback.

User Growth & Download Statistics

Add-on Writing AI Communication Education Privacy & Security

By:

Grammarly

Daily users:

549,452 -23,965

Rating:

4.09

(3,207) 2 new ratings

Version:

8.937.0 Last updated: 2026-04-24

Version code:

6230053

Creation date:

2014-12-17

Risk:

Permissions:

http://*/*
https://*/*
tabs
notifications
cookies
identity
storage

Content scripts matches:

<all_urls>
*.atlassian.net
mail.google.com
*.mail.google.com
quora.com
*.quora.com
*.slack.com
*.blackboard.com
*.blogger.com
publish.buffer.com

Size:

40.64MB

URLs:

Full description:

Source:

Firefox Add-ons Store

Data ingested on:

2026-06-21

Compare stats and ranking:

Ranking

# 29

Other rankings

#8 in Language Support

#16 in Social & Communication

#1 in ai grammar keyword 72

#1 in ai grammar check keyword 78

#1 in ai grammar checker keyword 71

Upgrade to see more rankings

Other platforms

Grammarly: AI Writing Assistant and Grammar Checker App (v14.1304.0)

37,000,000 4.50

(43,093)

Grammarly-AI Writing Assistant (v2.109.58711)

59,681,431 4.23

(260,887)

Grammarly: AI Writing and Grammar Checker App (v14.1138.0)

12,133,000 3.90

(1,161)

For Developers

Monetize with App Pass Boost with Extension Booster

Contact the developer

Chrome-Stats does not own this Firefox add-on. Please use these information below to contact the Firefox add-on developer.

Developed by:

Grammarly

Firefox Add-ons Store

https://addons.mozilla.org/firefox/addon/grammarly-1/

Permission Change History

2026-04-25: Version 8.936.0 → 8.937.0

Add Optional permissions: nativeMessaging clipboardRead

2025-05-14: Version 8.929.0 → 8.931.0

Add Permissions: identity

2022-07-20: Version 8.852.2307 → 8.901.0

Add Permissions: http://*/* https://*/*

Remove Permissions: <all_urls> clipboardWrite

Remove Optional permissions: clipboardRead

User Reviews

Users note solid basic grammar corrections and daily-writing usefulness, but the extension is hampered by recurring issues: you must sign in to use it, there are privacy concerns and data-collection practices, AI-driven features can worsen suggestions and push upgrades, and reliability problems like UI freezes or slow loading.

Pros

Core grammar corrections remain helpful for simple edits.
Useful for daily writing and general writing tasks.
Overall extension is good/useful despite issues.

Cons

Sign-in requirements and frequent login prompts create friction.
Privacy concerns and data collection on websites.
AI features degrade accuracy and come with upgrade/nagging prompts.
Reliability and performance issues, including UI freezing and slow loading.

Recent reviews

by Fi*****, 2026-06-19

DO NOT INSTALL THIS

by Ig*****, 2026-06-15

I used to love Grammarly. I tend to type too fast for my brain to process sometimes and I miss common things often. It always helped me out so I didn't have to reread everything again. But in the last 6 months or so, it's fixes don't even make sense. It wants me to change a word here and there that doesn't even make sense. It gives me incorrect spellings and insists my spelling is wrong, when I know it's not. I wish it were as great as it used to be, but it's gone downhill and I'll have to find something new.

by Em*****, 2026-06-12

View all user reviews ›

Is Grammarly: AI Writing and Grammar Checker App Safe?

Risk impact

Risk impact measures the level of extra permissions an extension has access to. A low risk impact extension cannot do much harms, whereas a high risk impact extension can do a lot of damage like stealing your password, bypassing your security settings, and accessing your personal data. High risk impact extensions are not necessarily malicious. However, if they do turn malicious, they can be very harmful.

Grammarly: AI Writing and Grammar Checker App requires a lot of sensitive permissions. Exercise caution before installing.

Risk impact analysis details

Critical Allows access to all websites, posing a significant security risk as it can monitor and modify data from any visited site.
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Risk likelihood

Risk likelihood measures the probability that a Firefox add-on may turn malicious. This is determined by the publisher and the Firefox add-on reputation on Firefox Add-ons Store, the amount of time the Firefox add-on has been around, and other signals about the Firefox add-on. Our algorithms are not perfect, and are subject to change as we discover new ways to detect malicious extensions. We recommend that you always exercise caution when installing a Firefox add-on.

Grammarly: AI Writing and Grammar Checker App has earned a fairly good reputation and likely can be trusted.

Risk likelihood analysis details

Medium This extension was updated in the past 3 months. New updates may not be stable or safe.
Low **** ********* *** ***** **** **** * ****** **** ***** ********** *** **** ****** ** ** ****** *** *****
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