GPTZero vs ZeroGPT

Updated November 2026 · AppBreakup editorial

GPTZero

AI detector that estimates how much of a text was written by ChatGPT, Claude or Gemini.

Free plan + paid

Visit GPTZero GPTZero profile

ZeroGPT

Free web-based AI text detector with a set of add-on writing tools.

Free plan + paid

Visit ZeroGPT ZeroGPT profile

The short answer

Both estimate how likely a text is AI-written and highlight suspect sentences. GPTZero is built for schools, with Google Docs, Classroom and Canvas integrations and Writing Replay to show how a document was typed. ZeroGPT is a broader free web toolkit with a higher free character limit, messaging-app bots and a humanizer. Teachers will usually prefer GPTZero; quick one-off checks suit either.

GPTZero or ZeroGPT: our take

The detectors do the same basic job: paste text, get a probability that it was machine-written, and see the sentences that triggered it. Neither score is proof, and both vendors' tools can flag human writing as AI, so results are best treated as a reason to look closer. The real differences are in who each product is built for.

GPTZero started in January 2023 as a tool for teachers and is still aimed at education. It plugs into Google Docs, Google Classroom, Canvas and Zapier, has a Chrome extension, and adds Writing Replay, which plays back how a Google Doc was typed over time as evidence of authorship. It also offers a plagiarism checker and a grammar and feedback tool, and supports English, German, Portuguese, French and Spanish. Short texts under 10,000 characters can be checked without an account; longer scans and extras need a free account or paid plan, and teams can buy shared word allowances.

ZeroGPT is a general web tool. Its free detector works without an account and allows 15,000 characters per check, and it has a large bundle of extras: plagiarism checker, paraphraser, summarizer, grammar checker, translator, AI image and video detector, and a humanizer that rewrites AI text to read more naturally. It also works through WhatsApp and Telegram bots. Paid plans add batch uploads and PDF reports, and its business API is pay-as-you-go. It quotes a 98.4% accuracy figure, but that is the vendor's own number. Selling a humanizer next to a detector is an awkward fit for educators trying to enforce academic honesty.

For teachers and schools that want detection inside the tools they already use, plus authorship evidence, GPTZero is the clearer fit. For an individual who just wants a quick free check of a longer passage, or wants access from a phone chat app, ZeroGPT is convenient. Organisations building detection into their own systems can use either API.

Choose GPTZero if…

Teachers and schools that want an AI check built into Google Docs, Classroom and Canvas
You need Browser extension, which ZeroGPT doesn't list
Short texts can be checked without signing up
Writing Replay shows how a document was actually typed

Choose ZeroGPT if…

Students, teachers and editors who want a quick free AI-text check without signing up
Basic detector works free and without an account
Highlights the specific sentences it flags as AI-written

What is GPTZero?

GPTZero checks a piece of writing and estimates how likely it is to be AI-generated, highlighting the sentences that look machine-written. It started in early 2023 as a tool for teachers worried about ChatGPT essays and is still aimed mostly at education, with integrations for Google Docs, Google Classroom and Canvas plus a Chrome extension. Around the core detector it has added a plagiarism checker, a grammar and feedback tool, and Writing Replay, which shows how a Google Doc was typed over time as evidence of authorship. You can paste short texts without an account; longer scans and the extra tools need a free account or a paid plan, and teams can buy shared word allowances. A developer API lets schools and platforms build detection into their own products. Like every AI detector, its scores are probabilities rather than proof, so results are best used as a prompt for a conversation rather than as a verdict.

What is ZeroGPT?

ZeroGPT is a web tool that estimates whether a piece of text was written by an AI model such as ChatGPT, Gemini or Claude. You paste text or upload files, and it returns an overall percentage along with the sentences it thinks are machine-written, highlighted in the text. Around the detector it has grown a bundle of extras: a plagiarism checker, paraphraser, summarizer, grammar checker, translator, an AI image and video detector, and a humanizer that rewrites AI text to read more naturally. The basic detector is free without an account and has a per-check character limit; paid personal and business plans raise limits, add batch uploads and PDF reports, and a pay-as-you-go API serves organisations that want to build detection into their own systems. It can also be used through WhatsApp and Telegram bots. Like every AI detector, its scores are probabilistic, so a result is a signal to look closer rather than proof of who wrote something.

Side by side

Attribute	GPTZero	ZeroGPT
Pricing	Free plan + paid	Free plan + paid
Open source	No	No
Self-hostable	No	No
Platforms	Web, Browser extension	Web
Best for	Teachers and schools that want an AI check built into Google Docs, Classroom and Canvas	Students, teachers and editors who want a quick free AI-text check without signing up
Status	Active	Active

Verified facts, compared

Facts both apps publish, checked on each vendor's own site.

Fact	GPTZero	ZeroGPT
API	Yes	Pay-as-you-go business API