Overview
Private, on-device grammar checking. Runs entirely in your browser — your writing never leaves your device.
Sidecar Grammar checks your writing as you type — privately, and entirely on your own device. Your text is never sent to a server and never leaves your browser. All grammar and spelling checking runs locally using the open-source Harper engine, compiled to run right inside Chrome. No account, no sign-in, no tracking, no analytics. HOW IT WORKS Turn it on with one click. Sidecar Grammar underlines likely spelling and grammar issues in text fields as you write. Hover an underline to see the suggestion, click to apply it. It's a lighter touch than most checkers — it flags the specific words that need attention rather than rewriting your sentences for you. WHERE IT WORKS Standard text boxes and text areas across the web, plus Gmail compose. You control it per site: a master on/off switch, and a "this site" toggle so you can turn it off anywhere you don't want it. PRIVATE BY DESIGN - Runs 100% on your device — nothing is uploaded - No data collected, stored remotely, or shared - Site access is only requested after you click Enable - Your settings stay in your browser Note: if underlines don't appear right after enabling on a page, reload the tab once. Powered by the open-source Harper grammar engine (github.com/Automattic/harper).
Details
- Version0.0.1
- UpdatedJuly 30, 2026
- Offered bySidecar Tools
- Size7.88MiB
- LanguagesEnglish
- Developer
Email
simonwork378@gmail.com - Non-traderThis developer has not identified itself as a trader. For consumers in the European Union, please note that consumer rights do not apply to contracts between you and this developer.
Privacy
This developer declares that your data is
- Not being sold to third parties, outside of the approved use cases
- Not being used or transferred for purposes that are unrelated to the item's core functionality
- Not being used or transferred to determine creditworthiness or for lending purposes
