Free AI Grammar Checker
That Explains Every Fix
Most free grammar tools fix your text and move on. NotchTutor explains why every correction is right — and tracks the mistakes you repeat so you stop making them. Free, private, and built for Mac.
Download Free for MacNo account. No credit card. No catch.
Free doesn't have to mean basic
Most free grammar tools are either paywalled, data-harvesting, or limited to spellcheck. NotchTutor is free because it's a native Mac app — and everything that makes it useful is included at no cost.
Most free tools
Free tier limits explanations to "see Premium"
NotchTutor
Every correction includes a full explanation
Most free tools
Free tools often store your text or use it for training
NotchTutor
Your writing is never stored — corrections are returned to your Mac and never retained by NotchTutor
Most free tools
Pattern tracking and history are locked behind a paywall
NotchTutor
Mistake pattern tracking is fully free, always
Everything you get, free
No tiers. No trials. No upsells. Here's exactly what NotchTutor gives you at no cost.
Real-time AI grammar correction
Catches errors in grammar, syntax, word choice, and sentence structure as you type — across every Mac app.
Plain-English explanations
Every correction includes a clear explanation of the rule, written so anyone can understand it — not grammar textbook labels.
Mistake pattern tracking
NotchTutor monitors which errors you repeat most and shows you your personal pattern report over time.
System-wide Mac coverage
Works in Mail, Slack, Pages, Notion, and every browser tab without extensions or copy-pasting.
Private by design
Your writing is never stored or used to train models. Corrections are generated via OpenAI's API and returned to your Mac. No account required, no usage tracking.
No account required
Download, install, and use NotchTutor without signing up for anything or sharing any personal information.
This is what "explains every fix" actually looks like
Not a red underline. Not a vague label. A real explanation you can learn from — every single time.
Before
"She is more smarter than him."
After
"She is smarter than him."
NotchTutor explains
"More smarter" is a double comparative — "more" and "-er" both signal comparison, so you only need one. Use "-er" for short adjectives (smart → smarter) and "more" for longer ones (intelligent → more intelligent).
Before
"I have been working here since 3 years."
After
"I have been working here for 3 years."
NotchTutor explains
"Since" is used with a specific point in time (since 2021, since Monday). "For" is used with a duration (for 3 years, for a long time). This is one of the most common preposition errors for non-native English speakers.
Before
"The report needs to be submitted on Monday till 5 PM."
After
"The report needs to be submitted by Monday at 5 PM."
NotchTutor explains
"Till" expresses a continuous action up to a point, while "by" sets a deadline. "On" is used for days, but "by" is correct here because you're giving a deadline, not a recurring event. "At" is correct for specific times.
Want to understand the deeper patterns? Read why grammar mistakes keep repeating and how to improve your business English fast . Also see our full guide for non-native English professionals .
Free and private — not "free" in exchange for your data
Many free tools fund themselves by analysing your writing, selling data, or pushing aggressive premium upsells. NotchTutor doesn't. Your writing is never stored, and there's no account to create.
Do you collect my writing?
No. Your writing is never stored or retained. Corrections are generated and returned to your Mac.
Do you track my usage?
No. NotchTutor does not monitor what you write, how often, or what you accept.
Do you show ads or upsell Premium?
No. There is no premium tier. The full tool is free.
Frequently asked questions
Is NotchTutor really free?
Yes. NotchTutor is free to download and use on macOS. The core features — real-time AI grammar correction, plain-English explanations for every fix, and mistake pattern tracking — are all available at no cost. There is no premium tier gating the features that actually make you a better writer.
What does a free AI grammar checker do that regular spellcheck doesn't?
Regular spellcheck catches misspelled words. An AI grammar checker understands sentence structure, context, and meaning — catching grammatical errors, awkward phrasing, incorrect word forms, and style issues that spellcheck misses entirely. NotchTutor also explains each correction and tracks recurring patterns, which no basic spellcheck does.
Does the free version of NotchTutor include explanations?
Yes. Explanations are not a premium feature — every grammar correction NotchTutor makes includes a clear explanation of why the original was wrong and why the fix works. This is the core of what makes NotchTutor useful for learning, not just correcting.
Does NotchTutor collect my data since it's free?
No. NotchTutor is free because it's a native Mac app, not because it monetises your data. Your writing is never stored, there is no usage tracking, and no account is required. Corrections are generated via OpenAI's API and returned to your Mac.
How is NotchTutor's free AI grammar checker different from Grammarly's free tier?
Grammarly's free tier offers basic grammar and spelling correction with limited feedback. NotchTutor's free offering includes explanations for every correction and pattern tracking — features that Grammarly limits to its paid Premium tier. For Mac users who want to improve their English, NotchTutor's free version provides more learning value.
Does NotchTutor store or share my writing?
No. NotchTutor never stores your writing, never uses it to train models, and never shares it. Corrections are generated via OpenAI's API and returned to your Mac. An internet connection is required, but nothing you write is retained.
The best things in grammar checking are free
Real corrections. Real explanations. Real privacy. Download NotchTutor and see what a free AI grammar checker looks like when it's designed to actually help you.
Download NotchTutor — Free for MacNo account. No credit card. No catch.