Free AI Grammar Checker

GPTINF's Grammar Checker scans your writing for spelling mistakes, punctuation errors, and grammar issues, then underlines each one directly in your text — red for spelling, blue for grammar — so you can see exactly where a problem is without losing the surrounding context. Every flagged issue comes with a suggested fix you can apply with one click, or you can accept every suggestion at once when you are working through a longer document like an essay, email, or blog post.

Unlike a simple spellchecker, GPTINF evaluates syntax patterns across full sentences, which means it can catch subject-verb agreement problems, misused homophones, awkward phrasing, and punctuation errors that basic tools miss. The checker shows you an improvements list summarizing every issue found, so you can quickly judge whether a suggestion fits the tone and meaning you intended before accepting it. Your judgment always stays in control: the tool proposes a fix, but you decide whether it preserves the voice and terminology of your piece.

A grammar pass works best as one step in a complete editing routine. After cleaning up mechanics here, run the same text through the Readability Checker to make sure sentence length and complexity match your audience, or use the Paraphrasing Tool if a sentence is grammatically correct but still reads awkwardly and needs a full rewrite. Students and professionals checking AI-assisted drafts can also run text through the AI Detector first, since grammar correctness and AI-writing patterns are two separate signals worth reviewing independently.