Fix grammar, spelling and punctuation. 100% free, no signup required.
Grammar Checker is a free online AI-powered tool from Promptnoter that helps you fix grammar, spelling and punctuation without any signup or software download. It works entirely in your web browser, which means your data stays private and never leaves your device. Whether you are a text professional, student, freelancer or content creator, this tool saves you time and effort.
Promptnoter is home to over fifty free AI tools across categories including Text & Writing, writing, coding, SEO, productivity and more. Our grammar checker is one of the most popular tools in the Text & Writing collection, alongside AI Prompt Improver and AI Prompt Library and AI Essay Writer. All tools share the same fast-loading, mobile-friendly design so you can move between them seamlessly.
Fill in the form fields above with your information, preferences or content.
Hit the generate button and the AI tool will process your input instantly.
Review the output, then copy to clipboard, download or share as needed.
The grammar checker is ideal for anyone who needs to fix grammar, spelling and punctuation. Students use it to improve their work, professionals rely on it to save hours of manual effort, and freelancers trust it to deliver high-quality results for clients. Since the tool is completely free, there is no risk in trying it out.
Promptnoter stands out because every tool is free, requires no account, and processes all data locally in your browser. There are no hidden fees, no premium tiers and no data collection. You can use the grammar checker on your phone, tablet or desktop with the same high-quality experience. For more text & writing tools, explore AI Prompt Improver, AI Prompt Library — all free and available right now.
The grammar checker catches common errors including double spaces, repeated words, missing punctuation, capitalization issues, and common spelling mistakes.
The grammar checker works best with English. It also handles basic checks for Spanish, French, German and other Latin-script languages.