Grammar Check by medialab
Free grammar checker for English writing. Private proofreading on web forms and docs with spelling and punctuation help. Core checking stays free.
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About this extension
Catch mistakes before you send or publish.
This add-on highlights grammar, spelling, and punctuation issues while you type in text boxes across the web.
Install once and write with more confidence every day.
This add-on highlights grammar, spelling, and punctuation issues while you type in text boxes across the web.
- Free core grammar and spell checking
- Works in email, docs, blogs, and comment fields
- Privacy-focused checking without sending your draft to a cloud editor
- Quick suggestions you can accept or ignore
Install once and write with more confidence every day.
Rated 4.3 by 6 reviewers
Permissions and data
Required permissions:
- Block content on any page
- Access browser tabs
- Access your data for all websites
Optional permissions:
- Access your data for writewithharper.com
More information
- Add-on Links
- Version
- 1.1.1
- Size
- 8.08 MB
- Last updated
- a month ago (Sep 29, 2026)
- Related Categories
- License
- Mozilla Public License 2.0
- Version History
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