Free · No signup required

Grammar checkerthat keeps you human.

Most grammar tools get your writing flagged as AI. Walter keeps it human, like Grammarly without the AI.

Used by 2.1M writers

80+ languages

What our grammar checker catches

The checker covers the four error categories that account for 96% of writing mistakes, and a fifth, AI-style "sloppiness," that's become the dominant problem in 2026.

Tone control, target-detector optimization, and 1.4s median latency. Built for production, not just demos.

Grammar mistakes

Agreement, tense, pronouns, modifiers. Each fix explains the rule.

Spelling errors

Homophones, typos, and regional variants across five English dialects.

Punctuation issues

Commas, splices, dashes, apostrophes, and quotation marks.

Style and clarity

Passive voice, wordiness, and readability across four style guides.

New · 2026

AI-tone cleanup

AI-assisted drafts read like AI. We rewrite tell-tale phrases in plain English.

Try our AI Humanizer

The grammar checker that won't get your writing flagged as AI

Whether you are writing an essay, a client email, or a hundred articles a week, Walter fixes the grammar without flattening your voice into something that reads like AI.

Students and academic writing
Fix grammar, spelling, and clarity in essays, theses, and research papers, without making them read like AI.
Non-native English writers (ESL)
Catch the grammar and phrasing mistakes that trip up non-native writers, with support across 80+ languages.
Business and email
Polish grammar and clarity in emails, reports, and client messages so they read professional and human.

Walter Writes vs. Grammarly, ProWritingAid, and LanguageTool

Free tier limits, style guide support, AI-tone cleanup, and API access, compared side by side.

GRAMMAR CHECKER	Walter Writes	Grammarly	ProWritingAid	LanguageTool
Style guide support		Business plan		Limited
Real-time browser check			Partial
AI-tone cleanup
API access	Soon	Enterprise only
Trains on your text		(Default on)
Local / offline mode	Browser-side for short text			Paid
Free			Trial	Limited

Grammar checker questions, answered

Privacy, accuracy, and how the score actually works.

Does using a grammar checker get your writing flagged as AI?

It can. Many grammar tools rewrite your sentences into polished, uniform phrasing that AI detectors associate with machine writing. Walter fixes grammar, spelling, and clarity while keeping your natural sentence patterns, so the corrected text still reads as human.

How is Walter different from Grammarly?

Grammarly often standardizes your writing until it sounds generic or AI-generated. Walter, built by the team behind a leading AI humanizer, corrects errors while preserving your voice and natural rhythm. It is a grammar checker designed not to make your text look AI-written.

Is Walter's grammar checker free?

Yes. You can check grammar, spelling, and clarity for free with no signup required. Paste or type your text and corrections appear automatically. Paid plans add higher limits and tools like the AI humanizer and AI detector.

How accurate is Walter's grammar checker?

Walter catches grammar, spelling, punctuation, and clarity issues and explains each suggestion so you can accept or reject it. Because you approve every change, your final text stays correct and authentically yours instead of being rewritten into a uniform style.

Will a grammar checker change my writing style or voice?

It can if the tool rewrites whole sentences. Walter is built to preserve your voice: it fixes errors and improves clarity without flattening your phrasing into generic or robotic prose, so the result still sounds like you wrote it.

What languages does Walter's grammar checker support?

Walter checks grammar in over 80 languages, including English, Spanish, French, German, Portuguese, Italian, and Dutch. The same voice-preserving correction applies across every supported language.