GPTZero vs Grammarly (2026): which should you pick?
As of Nov 13, 2026, we pick Grammarly: it is second in our ranking of writing tools, and it grades higher too, 3.0 against 2.4.
Checked Oct 5, 2026 and Nov 13, 2026 · graded Oct 10, 2026 and Nov 13, 2026 by ToolGPA
Grammarly grades higher on the free plan, ease of use and platforms. They get the same grade on value for money and features.
Price, platforms and features side by side. The table says where each price was read and when.
GPTZero
AI-writing detector with plagiarism, writing replay and an API
Grammarly
Writing assistant for grammar, tone and rewrites in any app
Which one is for you
Pick GPTZero if
- Fits if you grade or review writing and want to check it for AI
- Works for teachers whose classes run on Canvas or Google Classroom
Look elsewhere if
- Tight if you check a lot: the free plan stops at 10,000 words a month
- Skip it if you want one clear price, because paid prices vary by region and by test
- Pricey if you want a team: two-seat minimum, and the API is priced separately
- Watch out: the vendor's own wording suggests a detector is a guide, not proof
Pick Grammarly if
- Fits if you write in lots of places and want the same checks in each
- Works for people writing English as a second language, and students who want citation and plagiarism checks in one place
Look elsewhere if
- Skip it if a spell checker is all you need, as your browser has one
- Pricey if you pay month to month: $30, against $12 on yearly billing
- Not for you if you write in a language outside its main six, which only get spelling and basic grammar
- Tight if you lean on AI for free, with 100 prompts a month and no full-sentence rewrites or tone changes
- Watch out: Pro stops at 149 seats, Enterprise has no public price, and reviewers say it flags correct text and nags you to upgrade
How we grade them
| 2.4GPAGPTZeroFair | 3.0GPAGrammarlyVery good | |
|---|---|---|
| Value for money | CNo single US dollar list price could be read, and prices vary by region. Left in the middle of the category. | C$12 a member a month on yearly billing is the top of this category's normal range, where the dearer quarter starts at $12.00. Pay month to month and it's $30, nearly four times the $8.33 middle. LanguageTool, on its own list of rivals, asks less. |
| Free plan and trial | CA free plan up to 10,000 words a month, which a regular user will hit. | BFree lasts as long as you like, and the checking isn't capped: spelling, grammar and tone detection on everything you write. Rewrites are Pro only, AI stops at 100 prompts a month, and reviewers say it nags you to upgrade. |
| Features | BAI detection, writing replay, plagiarism, grammar feedback, a hallucination checker and an API. Nothing in the listing shows a gap in the core job. | BSpelling, grammar and tone everywhere you type, full-sentence rewrites, AI drafting, plagiarism and AI-text checks, Docs with agents that find citations and guess reader reactions, and team style guides. Advanced suggestions only cover six languages, and Docs is English only. |
| Ease of use | CNo store rating on record. You make an account and connect it to Docs or a class system. | B4.66 on the App Store from 225,387 ratings. That's a B, not an A, because an A wants 4.7, and 4.66 is 4.66. There's nothing to learn, mind: install it, type as normal, click what it underlines. |
| Platforms and integrations | BWeb and a Chrome extension, with Google Docs, Canvas, Google Classroom, Gmail and an API. | AWindows, Mac, four browsers, iPhone, iPad and Android, so every device type, and it works inside Gmail, Google Docs, Word, Outlook, Slack, Salesforce, Zendesk and Jira. No Linux app is listed. |
| Best for | checking whether text looks AI-written | checking your writing in every app |
The GPA is the average of the five grades: an A is 4 points, an F is none. The full reasons are on each tool's page: GPTZero and Grammarly. How we grade
Where they differ
- Grammarly also covers AI agents, citations and documents.
At a glance
| GPTZero | Grammarly | |
|---|---|---|
| Pricing | Free plan | Free plan |
| Starts at | Not published | $12 per member / month, billed annually |
| Free plan | Free plan covering up to 10,000 words per month, according to the vendor's pricing FAQ. | Spelling and grammar corrections, tone detection and 100 AI prompts a month. Docs is free to use, though some of its agents are limited to Pro. |
| Free trial | None listed | 7-day free trial of Pro for eligible individuals and teams, with $0 due at sign-up and an email reminder 2 days before it ends. |
| Web | ||
| macOS | ||
| Windows | ||
| iOS | ||
| Android | ||
| Browser extension | ||
| Made by | GPTZero | Superhuman Platform Inc. |
| Price read from | Not confirmed | grammarly.com |
| Checked | Nov 13, 2026 | Oct 5, 2026 |
Worth knowing
GPTZero
- Paid individual plan prices vary by region and by test; no single US dollar list price could be read.
- The free plan stops at 10,000 words a month.
- The team plan has a two-seat minimum and gives 500,000 words per member each month.
- The API is priced separately from the individual and team plans.
Grammarly
- The Free plan is capped at 100 AI prompts a month and leaves out full-sentence rewrites and tone adjustments.
- Pro costs $30 per member a month on monthly billing, against $12 a month when billed annually.
- Pro stops at 149 seats; larger organizations need Enterprise, which is priced through sales.
- Advanced grammar, clarity and tone suggestions cover six languages; the other supported languages get spelling and basic grammar only.
Key features
GPTZero
- AI detection
- Classifies text from models such as ChatGPT, Claude, Gemini and Llama; an Advanced Scan shows how different sentences score.
- Writing replay in Google Docs
- The Chrome extension records a replay of a document being written, including copy and pastes and unusual typing patterns.
- Plagiarism checker
- Checks whether content was copied from outside sources without attribution.
- Writing feedback and grammar check
- Gives feedback on clarity, tone and wordiness beyond a basic grammar check.
- Hallucination detector
- A separate checker aimed at hallucinated content in AI-written text, listed beside the AI detector.
- Classroom and API integrations
- Connects to Canvas and Google Classroom, and offers an API with code samples in 17 languages.
Grammarly
- Grammar, spelling and tone checks
- Corrects spelling and grammar and shows the tone of a message on every plan. Full-sentence rewrites and one-click tone adjustments are part of Pro.
- Works inside other apps
- Desktop apps for Windows and Mac, extensions for Chrome, Safari, Firefox and Edge, and iPhone, iPad and Android apps bring suggestions into tools such as Gmail, Google Docs, Word and Slack.
- Docs and AI agents
- Docs is a browser-based document editor with agents including AI Grader, Citation Finder, Reader Reactions, Humanizer and Paraphraser. Some agents are limited to Pro.
- Generative AI prompts
- Drafts and reworks text from a prompt. The allowance is 100 prompts a month on Free, 2,000 per member on Pro and unlimited on Enterprise.
- Plagiarism and AI detection
- Scans a document for text that matches other sources and for passages likely to be AI-generated. The plans page lists both checks under Pro.
- Team style controls
- Pro team accounts get style guides, brand tones, knowledge share, snippets and usage analytics, so a group writes with the same terms and voice.
Plans
GPTZero
Pricing could not be confirmed. See gptzero.me.
Grammarly
Free$0
Spelling and grammar corrections, tone detection and 100 AI prompts a month, for individuals.
Pro$12
per member / month, billed annually ($30 billed monthly)
Full-sentence rewrites, tone adjustments, style guides and brand tones, and 2,000 AI prompts a month. Sold for 1 to 149 seats.
EnterpriseCustom
Unlimited members and AI prompts, dedicated support, confidential mode, granular roles and data loss prevention. Sold through Superhuman Go.
Ways to pay less
GPTZero
No public discounts listed.
Grammarly
- Annual discount
Save up to 60% with yearly billing
Pro is $12 per member a month when billed annually and $30 when billed monthly. The plan toggle advertises a saving of up to 60% on yearly billing.
- Education
Discounts for educational institutions
The plans page FAQ says Grammarly offers discounts for educational institutions. Grammarly for Education is quoted through its education sales team.
Common questions
Which is cheaper, GPTZero or Grammarly?
As of Nov 13, 2026, GPTZero has no price we could confirm, and Grammarly starts at $12 per member / month, billed annually.
Which has a free plan, GPTZero or Grammarly?
As of Nov 13, 2026, both GPTZero and Grammarly have a free plan.
Which platforms do GPTZero and Grammarly run on?
As of Nov 13, 2026, only Grammarly lists macOS, Windows, iOS and Android apps. Both list a web app and a browser extension. A platform missing from a listing is one its maker's pages did not mention.
More comparisons
How this page was made
- The verdict at the top follows a fixed rule. When both tools are in the same category and either is in our top three for it, the verdict follows that ranking: the higher-placed tool is our pick. The top three weigh who each tool suits as well as its grades, so a pick can go against the GPA. Otherwise the page does not pick one and says which grades higher: the higher GPA first; on a tie, the one with a free plan, then the one that starts cheaper in dollars a month, counted the same way for both; if they are still level, what the choice depends on.
- The grades are our own, from each tool’s review or report card. The GPA is their average.
- Prices, plans and platforms come from each tool’s listing. The table above says where each price was read and when.
- The differences and the answers to the questions are worked out from those listings.