Grammarly vs ChatGPT for editing and proofreading
The always-on inline proofreader against the blank-page editor that can rewrite anything. Seven rounds, scored from current documentation and major reviews. Grammarly wins proofreading; ChatGPT wins editing; the margin is one round.
Grammarly
8.5 / 10
Catches errors where you type, one suggestion at a time, without touching your voice. Plagiarism and authorship tools ChatGPT lacks.
ChatGPT
8.3 / 10
Best at rewriting, restructuring and explaining why a passage fails. Free tier now unlimited for text.
Final score: Grammarly 4 — ChatGPT 3
Grammarly wins the proofreading rounds; ChatGPT wins the editing rounds.
Plain outbound links, no paid vendor relationships. Scores are editorial assessments of documented capabilities as of September 2026, based on Grammarly's and OpenAI's official plan pages and help centres plus major reviews. We did not run a lab test. See our disclosure.
Round by round
| Round | Grammarly | ChatGPT | Winner |
|---|---|---|---|
| 1. Catching errors | Reliable spelling, grammar and punctuation; PCMag calls it superb at exactly this | Catches the same errors when prompted, but bundles them with unrequested rewrites | Grammarly |
| 2. Rewrites and clarity | Full-sentence rewrites and tone adjustment on Pro; style suggestions are hit and miss | Rewrites, restructures, cuts word count, changes register on request | ChatGPT |
| 3. Working where you write | Browser extension, Google Docs sidebar, Word, Outlook, desktop apps; corrections appear as you type | Paste into chat or canvas; a separate window, a separate step | Grammarly |
| 4. Preserving your voice | Accept or dismiss each suggestion; the draft stays yours | Tends to smooth everything toward its own cadence unless tightly prompted | Grammarly |
| 5. Explaining and teaching | Short rule notes on each flag | Will explain why a paragraph fails, offer three fixes and argue with your structure | ChatGPT |
| 6. Integrity tools | Plagiarism checker on Pro; Authorship tracks human, AI and agent contributions | None built in | Grammarly |
| 7. Price and free tier | Free is basic; Pro about $12 a month annually or $30 monthly | Free tier has unlimited text chats on GPT-5.6 Luna; Plus $20; Go roughly $8 | ChatGPT |
Why Grammarly takes the belt for proofreading
Grammarly does one narrow job at scale: it watches the text box you are already typing in, flags what is wrong, and lets you accept or dismiss each fix. It runs as a browser extension in Chrome, Safari, Firefox and Edge, opens as a sidebar in Google Docs, and installs into Word, Outlook and the desktop. PCMag's January 2026 review rates it 4.0 and calls it superb at catching spelling and punctuation errors, with the caveat that its style suggestions are not always useful. That caveat is fair and it is also the point: for proofreading, you want a tool that is reliable on mechanics and quiet on style.
The company is now called Superhuman, having folded Grammarly, Coda and Superhuman Mail into one suite in late 2025, and the 2026 additions lean into trust rather than generation. Grammarly Authorship records which parts of a document were typed, pasted, or produced by an AI agent, with agent-specific attribution added in March 2026. The AI Rewriter agent shows students what an AI detector would flag and suggests phrases to revise in their own words. Pro still bundles a plagiarism checker. None of that exists inside ChatGPT.
Why ChatGPT wins the editing rounds
Editing is not proofreading. When a paragraph is grammatically fine and still bad, Grammarly has little to say and ChatGPT has plenty. Ask it why an opening drags and it will diagnose the problem, propose three alternatives at different lengths, and rewrite for a specific reader. Canvas, ChatGPT's side-by-side editing window, lets you highlight a passage and ask for a targeted change, then compare versions and restore an earlier one. Independent write-ups in 2026 keep reaching the same conclusion: Grammarly is better at catching mistakes silently in the background, ChatGPT is better at rewriting awkward sentences, adjusting tone and restructuring.
The trade-off is control. In one published comparison test, ChatGPT found every planted grammar error but attached eight extra stylistic rewrites that nobody asked for. If you use ChatGPT to proofread, tell it explicitly to fix mechanics only and list its changes; otherwise it will edit your voice out along with your typos.
What it costs
Grammarly Free covers basic grammar, spelling, punctuation and tone detection. Grammarly Pro is about $12 a month when billed annually, roughly $144 a year, or $30 month to month, and includes full-sentence rewrites, tone adjustment, brand voice and 2,000 generative AI prompts. ChatGPT's free tier gained unlimited text chats on GPT-5.6 Luna in August 2026, which makes it the most generous free editor available; Plus is $20 a month and Go roughly $8. Many people already pay for ChatGPT for other reasons, so the honest price of using it as an editor is often zero.
The verdict
Students, professionals and anyone writing all day in email and Docs: Grammarly. Always-on inline checking earns its keep, and Authorship matters if your school or employer asks how much was AI. Writers, marketers and editors reworking drafts: ChatGPT. Diagnosis, rewrites and structural feedback are where it is unmatched, and canvas keeps the process tidy. Occasional writers on a budget: ChatGPT Free, prompted to fix mechanics only. Non-native English writers: both, Grammarly for the daily catch and ChatGPT to explain the rule you keep tripping on.
Grammarly
- Inline corrections in every app and tab
- Accept fixes one at a time, voice intact
- Plagiarism checker and Authorship tracking
- Style suggestions are uneven; Pro is $30 monthly
ChatGPT
- Best rewrites, restructuring and explanations
- Canvas for targeted, versioned edits
- Free tier with unlimited text chat
- Over-edits unless tightly prompted; no inline mode
The verdict: Grammarly to catch it, ChatGPT to fix it.
The tools overlap less than the marketing suggests. Grammarly polices the text you have written; ChatGPT rebuilds it. Most serious writers end up with both, which costs about $12 a month if you already pay OpenAI. If you can only keep one, keep the one that matches your failure mode: typos, Grammarly; flat prose, ChatGPT.
Quick answers
Is Grammarly or ChatGPT better for proofreading?
For proofreading, Grammarly. It flags errors inline as you type, lets you accept fixes one at a time, and does not rewrite sentences you did not ask it to touch. ChatGPT catches the same errors but tends to bundle them with stylistic rewrites you must then unpick.
Can ChatGPT replace Grammarly?
For occasional writers, often yes: ChatGPT's free tier now has unlimited text chats, and canvas handles paragraph-level editing well. Heavy writers who live in Gmail, Docs and Word usually keep Grammarly for the always-on inline checking and plagiarism tools ChatGPT does not offer.
How much do Grammarly Pro and ChatGPT Plus cost?
Grammarly Pro is about $12 a month billed annually (roughly $144 a year) or $30 month to month, and includes 2,000 generative AI prompts. ChatGPT Plus is $20 a month, with a Go tier at roughly $8. Both have free tiers; ChatGPT's free tier is the more generous.
