Grammafy — On-Device Grammar Checker

Private, on-device grammar and spelling corrections as you type. Click an underlined word to fix it. Your writing stays local.

Grammafy checks grammar and spelling where you write, using Chrome's built-in on-device AI. No separate editor. No Grammafy account. Your writing stays on your device. FIX IT INLINE • Type in a supported textarea or rich-text editor. • See colored underlines for possible grammar, spelling, punctuation, and capitalization issues. • Click an underline to see a suggestion, then click the replacement to update your text in place. • Dismiss a suggestion to keep your original wording, or click the field's suggestion count to apply the current suggestions together. YOU STAY IN CONTROL • Turn checking on or off from the popup. • Pause Grammafy on a particular site. • Optionally enable checking in single-line text and search fields. • Password inputs and fields marked to opt out are excluded. PRIVATE PROOFREADING The extension processes writing locally through Chrome's built-in AI APIs. It does not send your writing to a Grammafy server, and it contains no advertising or analytics. Chrome may synchronize your preferences, paused-site list, and accepted-suggestion count when browser sync is enabled. The writing itself is never placed in that sync storage by Grammafy. BEFORE YOU INSTALL Grammafy requires Chrome 138 or newer and a device supported by Chrome's built-in AI. Chrome may need to download Gemini Nano once; this can require several gigabytes. The popup shows whether the model is ready and offers setup when supported. Proofreading is focused on English. Suggestions are generated by AI and can miss issues or be incorrect; you choose which suggestions to apply. Grammafy works in supported editable fields on regular web pages. Some custom editors, protected browser pages, and fields that opt out are not supported. Better writing. On your device.