Fix Grammar in 3 Simple Steps
Check, correct, and humanize your text in seconds
Paste Your Text
Copy any text with grammar issues into the editor - essays, emails, articles, or any written content.
Check Grammar
Our AI scans for grammar, spelling, and punctuation errors and generates a corrected version of your text.
Get Corrected & Humanized Text
Receive error-free text that's been humanized to sound natural and pass all AI detectors.
Why Use SupWriter's Grammar Checker?
More than grammar correction - a complete writing improvement and humanization tool
Comprehensive Grammar Fix
Catches and fixes grammar errors, subject-verb agreement, tense issues, and sentence structure problems.
AI Detection Safe
After fixing grammar, the humanization step ensures your text passes Turnitin, GPTZero, and all AI detectors.
Multiple Check Modes
Basic mode fixes errors. Thorough mode improves structure. Style mode enhances word choice and clarity.
110+ Languages
Check grammar in over 110 languages with language-specific rules and corrections.
Instant Corrections
Get your text checked, corrected, and humanized in seconds. No waiting or complex setup.
Spelling & Punctuation
Beyond grammar - fixes spelling mistakes, punctuation errors, and commonly confused words.
Frequently Asked Questions
More Grammar Tools
Explore specialized grammar and writing tools for your specific needs
Grammar Checker for Essays
Fix grammar, spelling, and punctuation in essays. Get humanized output that passes AI detectors.
Try it freeGrammar Checker for Students
Student-friendly grammar checker designed for assignments, coursework, and academic writing.
Try it freePunctuation Checker
Fix commas, periods, semicolons, and all punctuation errors. Get perfectly punctuated text.
Try it freeSpell Checker
Catch and fix spelling mistakes, typos, and commonly confused words in your writing.
Try it freeSentence Checker
Check sentence structure, grammar, and clarity. Fix run-on sentences and fragments.
Try it freeFree Grammar Checker
Try our free online grammar checker with 300 words free. No sign-up required.
Try it freeTested and Proven Across All AI Detectors
We test every rewrite against leading detection tools like GPTZero, Turnitin, ZeroGPT, and more. Our system is updated weekly to adapt to new detection methods and eliminate flagged patterns.
99%success rate across all major detection platforms
Reviews
What our users say
Thousands of writers trust SupWriter every day
I've been using SupWriter for weeks, and it's become essential to my academic writing and research workflow. As a Ph.D. student in environmental law, I'm constantly drafting, refining, and translating complex texts, and SupWriter makes the whole process far more efficient and less stressful.
It's so great and I love this app. Everyone should use it. It helped me pass my essay!
I really like this app. It rephrases my text so well that Turnitin doesn't pick it up. Pretty amazing.
What impressed me most is how seamlessly SupWriter polishes my drafts. My clients noticed the difference in quality and tone immediately.
Absolutely wonderful. The best AI humanizer I've used, especially for scientific writing.
This tool lets me do so many things faster, and its features are genuinely useful.
Really good. I didn't expect it to be this great. It genuinely enhanced my writing. Give it a try.
This product is so good. I'll choose it over and over again. It has my heart. ❤️
The Fix Selection feature is a game changer. I can select any text and improve it, fix the grammar, or make it shorter, and my content workflow has never been faster.
Excellent service, really helpful for job applications, and it even has an AI detector. I'd highly recommend it to students, professors, and writers. An amazing writing tool.
It was amazing. I upgraded, and since then my work has consistently scored high marks.
The best humanizer ever.
It was great, especially in a foreign language. It helped the adjectives come out smoother than I expected!
I'm on the Ultra Monthly plan and bought $20 in extra credits. This platform is super good, and I'm planning to switch to the Yearly plan soon.
Precisely written and a very nice app. I recommend everyone give it a try.
I was amazed to see the AI-flagged text identified so accurately. It really helps crack down on AI interventions.
My professor commended the uniqueness of my essay after I used SupWriter to make it sound natural. Strongly recommended for students!
The website is fantastic. It's clean, modern, and visually appealing. Navigation is intuitive, pages load fast, and everything works well on desktop and mobile. A smooth, enjoyable experience. I'm really impressed!
Really, the only one that passed the YouScan detector.
It's been a great tool to use, and very helpful.
My experience with the AI detector was great. The interface is simple and easy to navigate, and results came back quickly with useful detail.
This experience has been amazing, and the service is extremely helpful.
My experience was amazing. SupWriter is very easy to use, and it actually works!
Impressed by the quality, and cheaper than other platforms.
SupWriter is great. It helps me become a better writer and a better student overall.