# Free AI detector that shows how sure it is

Textlume reads your text sentence by sentence and gives you a likely range, a High, Medium or Low confidence rating and a mark on every sentence. This AI checker is free with no account: up to 250 words per check, one check a day.

## How it works

The AI detector gives its clearest reading on a full passage, like an essay section or a blog draft.

1. **Paste or upload your text**
   Paste a few paragraphs or upload a Word file or PDF. The language is read from the text, and you can change it under Language.
2. **Run the check**
   Press Check for AI. One plain sentence at the top says what the reading means.
3. **Start with the marks**
   Open Most AI-like sentences to jump to the strongest signals, then read each one in context.

## Free limits

| Tool | No account | Free account |
| --- | --- | --- |
| Before you submit | Up to 250 words per run, 1 run per day | Up to 250 words per run, 1 run per day |

## Frequently asked questions

### Is there a free AI detector?

Yes. Textlume gives you one free check a day without an account, each up to 250 words. A free check gets the full reading: the range, the confidence rating and a mark on each sentence. The [pricing page](/pricing) shows what paid plans add, such as more words and batch checks.

### Do AI detectors actually work?

As a signal, yes. As proof, no. Every detector misses some AI text and flags some human text. In our October 2026 test, Textlume caught 68 of 75 English machine texts and flagged none of 150 native English human texts. None in 150 is not a promise of never: for a sample that size, the honest ceiling on false flags is about 2.5 percent. That is why each reading comes with a range and a confidence rating. The [accuracy page](/accuracy) has the counts for every language, weak spots included.

### Can it check text from ChatGPT, Gemini or Claude?

Yes. Textlume reads the text the same way whichever assistant produced it, so it works as a ChatGPT detector and for the others too. It looks at the writing, not where it came from, so it won't tell you which assistant wrote a passage.

### Can teachers use an AI detector on student essays?

Yes, as one input to a conversation and never as the final word. Textlume shows which sentences read as AI and how confident the reading is. Put that next to the student's drafts and version history, and be extra careful with a Low rating or with a writer still learning English.

### Which languages can it check?

Textlume is calibrated for 13 languages: English, Spanish, German, French, Italian, Portuguese, Dutch, Polish, Russian, Turkish, Arabic, Hindi and Indonesian. It reads the language from your text, and you can set it yourself. A text in any other language gets no calibrated figure. The accuracy page has the results for each language.

### How many words do I need to paste?

At least 50 words, and more is better. Anything shorter is turned away. From 50 to 99 words, Textlume gives a reading but holds the rating at Low and tells you why. A full essay section or a complete email gives a clearer picture.

### Is the text I paste saved?

Not if you're signed out. The text is read for the check and nothing is kept. Signed in, each check stays in your history for up to one year, and you can delete entries or turn history off. Checks sent through the API aren't kept either.

### Why would my own writing be flagged as AI?

Plain, polished, predictable prose can look like model output, and detectors have a known habit of flagging non-native English writers, which Textlume measures and publishes. Editing tools matter too. A grammar checker that fixes spelling and commas leaves your sentences as you built them, while a tool that rewrites whole sentences hands the wording to a model, and that wording is what a detector reads. If a flag seems wrong, check a longer sample and keep your drafts ready.

### Can it show which parts of a text are AI-written?

It marks each sentence as AI, human or unclear, but it can't prove who wrote any one of them. Textlume says Mixed only when marks land on both sides. The overall figure reads the whole text and is not a count of AI sentences.

### Does it catch paraphrased or humanized AI text?

Sometimes. Reworded AI writing can still read as AI, but we publish no separate figure for humanized text, so don't read a human result on a reworked draft as a clean bill. For English text, Textlume also adds a note when its second model sees signs of AI editing or a humanizer.

### Can it tell which AI model wrote a text?

No. Textlume reads whether a text looks machine-written, not which model wrote it. Our test set covers 9 current chat models, plus continuations and paraphrases. One known weak spot: a text where a model carries on from a human-written opening is caught far less often.

- [View this page on the site](https://textlume.com/)
- [Pricing](https://textlume.com/pricing.md)
- [How we measure accuracy](https://textlume.com/accuracy)