A private AI detector you can check for yourself
IsThisAiWritten is a private AI detector: paste your text below and the analysis runs inside your browser tab, so the text you check is never uploaded. It is free, needs no account and has no word limit. You don't have to take our word for the privacy part. Further down, this page shows how to confirm it with your browser's developer tools in about a minute, and what other detectors do with the text you give them.
Why use a private AI detector
- Free, with no sign-up. No account, no email and no credit card, so there is nothing that links a check to you. No credits, no daily cap, no paywall and no premium tier.
- No word or character limit. Paste a whole thesis or novel and check it in one go.
- Nothing is uploaded. The text never leaves your device; the check runs in your browser.
- Your text is never stored, shared, sold or used to train anything. We never receive it, so there is nothing to store.
- Every word is scanned, never a sample.
- A report that explains itself: an AI-likeness score, sentence-by-sentence highlights, style notes with one-click plainer wording, a hidden-character and look-alike-letter cleaner, and a narrative fingerprint for fiction.
- Opens .txt and .docx files right in the browser. The file is read on your device, never sent anywhere.
- No ads where you paste text.
What happens to your text during a check
When you paste text and press Check for AI, the page first cleans it, setting aside invisible and look-alike characters, and splits it into sentences. It then hands the text to a detection model running in a background worker inside the same tab. The model scores overlapping windows of the text, and the page turns those scores into a result. All of this happens in your device's memory. Close the tab and the text is gone. We never receive it, so there is nothing for us to store or share.
What the page downloads, and from where
Model and code downloads only go one way, from these hosts to your browser. None of them ever receives your text:
| Host | What it sends you | When |
|---|---|---|
| isthisaiwritten.com | The page, its styles, scripts and small data files | Every visit |
| cdn.jsdelivr.net | The open-source library that runs the model in the browser | First full check, then cached |
| models.isthisaiwritten.com | The open detection model, from our own copy | First full check, then cached |
| huggingface.co | The same model, only if our copy is unavailable | Backup only |
| openrouter.ai | A public list of AI model names, used to show the newest releases on the home page | At most once a day, with no text attached |
The model is TMR, an open RoBERTa-based classifier published on Hugging Face, so anyone can see exactly what is being run. The full list is on the privacy page, including Google Analytics, which counts page views, pauses while a scan runs and never sees your text or results.
How to verify the private AI detector in DevTools
- With this page open, open your browser's developer tools: F12 on Windows and Linux, or Option-Command-I on a Mac. Choose the Network tab.
- Paste some text into the box above that includes a word nobody else would use, such as a made-up surname like “Quillfeather”. Press Check for AI.
- Watch the requests appear. On a first check you'll see the model files arrive from models.isthisaiwritten.com (or huggingface.co, if our copy is unavailable) and the runtime library from cdn.jsdelivr.net.
- Use the search in the Network panel to look for your made-up word across all requests. Nothing matches, because no request carries your text.
How other AI detectors handle your text
Most detectors run on the company's servers, so your text is sent there. What happens next differs a lot. We read each company's privacy policy and help pages in October 2026; this is what they say they do, not the result of an audit.
| Tool | Kept after the check | Used to train models |
|---|---|---|
| IsThisAiWritten | Nothing: the text never leaves your browser | Never, because the text is never uploaded |
| Pangram | Saved to your history until you delete it; zero retention on enterprise plans | Never |
| ZeroGPT | FAQ: discarded after the result; policy: kept only as long as reasonably necessary | No |
| Winston AI | While the report exists; removed within 30 days of deletion, backups up to 90 days | Only with opt-in consent |
| GPTZero | Dashboard text kept; API text not stored | Dashboard inputs used in aggregate to improve the service |
| Turnitin | The institution chooses whether papers are stored | May train its detection classifier |
| Copyleaks | As long as necessary | Yes, unless you opt out |
| Originality.ai | As long as reasonably necessary | Yes, unless you opt out |
| QuillBot | While your account is open | Yes by default; opt-out in its browser extension |
| Grammarly | Varies by data type | On by default for individual users |
In the table above, IsThisAiWritten is the only tool that never receives your text at all.
Product pages and policies don't always agree. Quetext's detector FAQ says scans are not stored or used for training, while its privacy policy, updated in October 2026, says user content may be included in AI training. When the two differ, the policy is the one to read.
The other way to keep text on your own machines is to host an open-source detector. Binoculars, from an ICML 2024 paper, is free to run, but it loads two Falcon-7B models, so it needs serious hardware, and its authors describe it as for academic purposes only.
When a private AI detector matters
Running locally removes the question of what a server does with your text, which matters in situations like these:
- An unpublished novel or a pitch you don't want sitting in someone else's database.
- A client report or contract draft covered by a confidentiality agreement.
- Student essays, where a school's rules may limit sending work to outside services.
- A message you received and want to check without forwarding it anywhere.
Because nothing is uploaded, there is also no sign-up and no stored history of what you checked. The publishers page covers handling submissions this way.
Tips for keeping any check private
Because the analysis runs on your device, your own computer is the only place the check happens. A few habits keep everything around it private too, on this site or any other:
- Browser extensions with permission to read pages can see what you paste into any site, so review which ones you have installed.
- On a shared computer, close the tab when you're done and leave Save scans on this device switched off (it is off by default).
- For your own peace of mind, repeat the DevTools check above whenever you like. It takes about a minute.
The site's host, Cloudflare Pages, processes ordinary request data such as your IP address to deliver the page, as any web host does, and never the text you check. Our methodology page explains how the detector is tested.
Sources
- TMR AI text detector (ONNX) on Hugging Face, checked October 2026
- Pangram, Does Pangram train on my data?, checked October 2026
- Pangram privacy policy, checked October 2026
- Pangram, Can Pangram not store my data?, checked October 2026
- ZeroGPT FAQ, checked October 2026
- ZeroGPT privacy policy, checked October 2026
- Winston AI privacy policy, checked October 2026
- GPTZero, Are you storing data from API calls?, checked October 2026
- GPTZero, Do I retain ownership of the work?, checked October 2026
- GPTZero, Privacy and security, checked October 2026
- Turnitin, Standard assignment settings, checked October 2026
- Turnitin Trust Center, checked October 2026
- Copyleaks privacy policy, checked October 2026
- Originality.ai privacy policy, checked October 2026
- QuillBot, How does QuillBot use my data?, checked October 2026
- Grammarly, Product Improvement and Training control, checked October 2026
- Grammarly privacy, checked October 2026
- Quetext privacy policy, checked October 2026
- Binoculars repository and licence, checked October 2026
- Hans et al., Spotting LLMs With Binoculars, checked October 2026
Questions
Does it keep a history of what I checked?
Only if you ask it to. Save scans on this device is off by default; switched on, it keeps your scans in your own browser's storage, never on a server. Clear this site's data in your browser settings to remove them.
Is there a word limit on private checks?
No. There is no word or character limit, so a whole manuscript, report or thesis goes in as one check, and every word is scanned on your device.
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