A QuillBot AI detector alternative without the 1,200-word cap

IsThisAiWritten is a free QuillBot AI detector alternative for longer work: no word limit, no daily cap and no account, and it runs in your browser, so nothing you paste is sent to us. QuillBot's AI detector is free to try, but the free version stops at 1,200 words per scan and six scans a day, and QuillBot says user inputs are used for training to improve its services.

IsThisAiWritten vs QuillBot for AI detection

QuillBot's limits and features are from its own pages at the time of writing.

Why look for a QuillBot AI detector alternative?

QuillBot cites a 99% detection rate from independent RAID evaluations, and says that when a result is unclear its model leans towards calling the text human, to cut down on false positives. The free limits are the sticking point. Do the arithmetic on a long piece. A 10,000-word undergraduate dissertation needs nine separate scans at 1,200 words each, and with six free scans a day, that takes two days. A 3,000-word essay fits in three scans, so checking it once, revising and checking again uses all six for the day.

Splitting also works against the detector. QuillBot's own advice is to analyse your entire text at once for the most accurate result, and a 1,200-word slice gives any model less context than the full document. You end up with several percentages that may not agree.

Then there is training. QuillBot's help center says your inputs and usage data are used to provide the service and for training to improve it. In the browser extension, anyone can switch off storage of text inputs and account holders can also switch off training. Team Plan inputs are never used for training. If you are checking a client's draft or a student's essay, you may not want it in that pool by default.

How IsThisAiWritten handles the same job

One check for the whole document

Paste the full essay or chapter and you get a single outcome (Human, Mixed, AI or Inconclusive), an AI-likeness score and one sentence map across the text. No chunking, and no daily scan count, so the 10,000-word dissertation above is one check instead of two days of scans. See AI detector for essays.

No training switch to look for

QuillBot's switches for storage and training sit in its browser extension. We have no such switch because we have nothing to switch off: the check runs inside your browser and the text never reaches us. The private AI detector page explains how.

Style notes with plainer wording

Besides the sentence map and an AI-likeness score, the report adds style notes on your phrasing, each with a one-click plainer wording you can take or leave. They explain the result; they don't decide it. If you want to know whether paraphrasing tools hide AI writing from detectors, the article on AI humanizers looks at that question. How our detector is tested is on the methodology page.

A note on paraphrasing, scores and disclosure

A lot of people who check text with QuillBot also write with QuillBot, and the temptation is to keep paraphrasing until the score drops. QuillBot's own detector page advises against that: if you used AI in your work, it says, disclose it rather than revising to change a score. We agree. A detector score is a rough signal, and chasing a lower number tells you nothing about whether the work meets your course's or client's rules.

What a detector can do is point at passages that read as flat or generic, which are worth rewriting for their own sake. Our article on the signs of AI writing covers what to look for by eye, and the student guide covers what to keep (drafts, notes, sources) in case your work is ever questioned.

Other QuillBot AI detector alternatives

Scribbr also caps each check at 1,200 words, but allows unlimited checks with no sign-up and says it does not store submissions (Scribbr alternative). GPTZero takes 10,000 characters per scan without an account, and up to 150,000 with a free one (GPTZero alternatives). Grammarly has a free detector with a 25,000-character box, with sentence detail in its Pro plan (Grammarly alternative). See also QuillBot vs GPTZero.

Sources

1. QuillBot AI Detector (free vs Premium limits, languages, accuracy claim), checked October 2026
2. QuillBot Premium plans, checked October 2026
3. QuillBot blog: QuillBot's AI Detector (no sign-up under 1,200 words), checked October 2026
4. QuillBot Help Center: How does QuillBot use my data?, checked October 2026
5. Scribbr AI Detector, checked October 2026
6. GPTZero FAQ, checked October 2026
7. Grammarly AI Detector, checked October 2026