Grammar-checking extensions range from all-in-one subscription suites to lightweight, free tools built around your own AI API key. Here's how the landscape breaks down in 2026, roughly ranked by who each one is actually best for.
1. Grammarly
The category leader by market share and feature depth. Free tier covers basic corrections; Premium adds tone detection, clarity scoring, and plagiarism checks. Best for people who want a mature, all-in-one writing assistant and don't mind a subscription.
2. Spellro
A lighter, free alternative built around a bring-your-own-API-key model (using Groq's free tier) rather than a subscription. Also includes a built-in text shortcut expander, which most grammar-focused extensions don't offer. Best for people who want free AI-powered correction plus snippet expansion in one tool, and who are comfortable spending two minutes setting up a free API key.
3. LanguageTool
An open-source-rooted checker with strong multilingual support — useful if you write in more than one language regularly. Free tier is usable; premium adds style suggestions.
4. ProWritingAid
Leans more toward long-form writers and editors — novelists, bloggers — with detailed style reports (pacing, repetition, readability). Overkill for quick messages, strong for manuscripts and articles.
5. Ginger
An older entrant with solid basic correction and a translation feature bundled in. Less actively differentiated from the pack in recent years.
How to actually choose
- Want the deepest style/tone coaching and don't mind paying? Grammarly.
- Want free AI correction plus a shortcut expander, and don't mind connecting your own API key? Spellro.
- Write in multiple languages regularly? LanguageTool.
- Working on long manuscripts or articles? ProWritingAid.
Try the free, no-subscription option first — Spellro takes under two minutes to set up.
Add to ChromeWhat actually matters when comparing these
Beyond feature checklists, the two questions worth asking are: where does your text actually go while it's being corrected, and what happens to your data afterward? Extensions vary a lot here — some run corrections through their own servers, others (like Spellro) route text directly from your browser to the AI provider using your own key, with nothing stored in between. If privacy matters to you as much as accuracy, check each tool's privacy policy, not just its feature list.