Grammarly: AI Writing and Grammar Checker App Firefox

Grammarly: AI Writing and Grammar Checker App

By: Grammarly Add-on
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.

Overview

Firefox Add-ons Store
Daily users
506,447 ▼ 4.18K
Data as of 2026-07-31
Rating:
4.09
(3,210)
Version:
8.937.0
Last updated: 2026-04-24
Download
Ranking
#28
Overall
Category rank
#8
Language Support

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

Manifest V2 Add-on Writing AI Communication Education Privacy & Security
By:
Grammarly
Daily users:
506,447 -4,184
Rating:
4.09
(3,210)
Version:
8.937.0 Last updated: 2026-04-24
Version code:
6230053
Creation date:
2014-12-17
Risk:
Very high risk impact Low risk likelihood
Permissions:
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
    • See more
Size:
40.64MB
URLs:
Privacy policy
Full description:
See detailed description
Source:
Firefox Add-ons Store
Data ingested on:
2026-07-31
Compare stats and ranking:

Ranking

# 28
Other rankings
Upgrade to see more rankings

Other platforms

Chrome
Grammarly: AI Writing Assistant and Grammar Checker App (v14.1316.0)
35,000,000 4.50 (43,101)
Android
Grammarly-AI Writing Assistant (v2.112.100047)
60,015,232 4.25 (262,177)
Edge
Grammarly: AI Writing and Grammar Checker App (v14.1140.0)
11,778,786 3.90 (1,172)

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
In itself, extremely useful plugin that I use daily. However, newer versions are totally unusable. Clicking a suggestion does not change the text anymore. That is like the most basic thing it should do. I had to downgrade to an older version to get this working again. Currently using 8.899.0. More or less random older version that still works.
by Fi*****, 2026-07-21
No funciona en català.
by Fi*****, 2026-07-16
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
  • Low This extension was updated more than 6 months ago. Older versions are more likely to be stable and safe.
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