The Grammar Checker
That Keeps Your Voice
Fix grammar, spelling, and style — without losing what makes your writing yours. Powered by 7-stage AI that understands your unique voice.
10,000+ writers • 1M+ corrections • Voice preserved 94% of the time
How HumanGrammar Works
Paste Your Text
Drop in any text — an email, essay, message, or document.
AI Corrects Grammar
Our 7-stage pipeline fixes grammar, spelling, and style issues.
Your Voice Stays Intact
Voice Lock technology ensures corrections match your natural writing style.
See the Difference: Grammar Fixed, Voice Preserved
Original
“i been thinking bout how we aint never gonna get this done if yall keep procrastinating”
Typical Grammar Checker
“I have been thinking about how we are never going to get this done if you all keep procrastinating.”
HumanGrammar
“I've been thinking about how we're never gonna get this done if y'all keep procrastinating.”
Built for Every Writer
Students
Fix essays without losing your authentic voice
Professionals
Polish emails while keeping your personal tone
Writers
Clean up drafts without an editor rewriting your style
Developers
Fix docs and comments — API access included
Non-Native Speakers
Correct grammar while preserving your unique expressions
Content Creators
Edit posts without sounding like everyone else
Powerful Features for Better Writing
Voice Preservation Technology
Our Voice Lock system ensures corrections match your natural writing style. Your text, your voice — always.
7-Stage AI Pipeline
From rule-based fixes to constrained semantic rewrites, each stage is purpose-built for accuracy.
Adjustable Aggressiveness
Dial correction intensity from 0 (minimal) to 3 (full rewrite). You control how much changes.
Voice Drift Scoring
Every correction is measured on a 0.0-1.0 scale. See exactly how much your voice shifted.
API Access for Developers
Full REST API with async job support. Integrate grammar checking directly into your product.
Real-time Processing
Get corrections in under 2 seconds for most texts. Async jobs handle longer documents.
Writers Love HumanGrammar
“Finally, a grammar checker that doesn't make me sound like a robot. My emails still sound like ME.”
Sarah K.
Marketing Manager
“I was skeptical, but the voice drift score convinced me. 0.04 drift on my last essay. Incredible.”
James T.
Graduate Student
“We integrated the API into our CMS. Our writers are much happier — corrections without the corporate tone.”
Priya M.
Engineering Lead
Frequently Asked Questions
While Grammarly and similar tools aggressively rewrite your text into a uniform, polished tone, HumanGrammar is built around voice preservation. Our 7-stage pipeline fixes errors without stripping your personality, slang, or stylistic choices. Every correction is scored for voice drift so you always know how much changed.
Voice preservation means your corrected text still sounds like you wrote it. We measure this with a Voice Drift Score (VDS) — a 0.0 to 1.0 scale where 0.0 means the text is identical in voice and 1.0 means a complete rewrite. Our Voice Lock technology automatically reverts corrections that drift too far from your original style.
Yes! The free plan includes 50 grammar checks per day with full voice preservation. No credit card required. For higher volumes, API access, and advanced features like custom style guides, check out our paid plans.
Absolutely. HumanGrammar provides a full REST API with synchronous and asynchronous endpoints. You can integrate grammar checking directly into your app, CMS, or workflow. See our API documentation for details, example clients, and SDKs.
The Voice Drift Score (VDS) is a composite metric from 0.0 to 1.0 that measures how much your text's voice changed after correction. It combines five sub-scores: lexical drift, contraction drift, sentence length drift, formality drift, and punctuation drift. A score below 0.15 means virtually no voice change. Above 0.35 triggers automatic fallback to safer corrections.
Currently, HumanGrammar supports English (US and UK variants, configurable per account). Spanish, French, German, and Portuguese are on our v1.1 roadmap. Community-contributed language packs are planned for v2.
The pipeline processes text through: (1) rule-based grammar fixes via LanguageTool, (2) model-based grammatical error correction, (3) clarity rewrites for ambiguous sentences, (4) Voice Lock to revert over-corrections, (5) drift scoring to measure voice change, (6) selection logic that falls back to safer outputs if drift is too high, and (7) final response assembly with structured diffs.
By default, text is stored temporarily for job processing and is deleted according to your retention settings. You can set retention to zero for immediate deletion after processing. Local-only mode ensures your text never leaves our infrastructure. We never use your text for model training.
Start Writing Better —
Without Losing Your Voice
No signup required. Start checking grammar instantly.