Platform & Safety
AI text detection
Estimates whether text was written by a model, for schools, publishers and trust & safety.
Cheapest right now
As of October 2026, the cheapest API for ai text detection is Sapling AI Detector API from Sapling at $0.03 per 1K words, then Originality.ai AI detector API from Originality.ai at $0.119. Prices verified Oct 18, 2026 against each provider's pricing page; confirm there before you buy.
What it is
AI text detectors read a piece of writing and estimate how likely it is that a language model produced it, often highlighting the sentences that look generated. Some also check for plagiarism or guess which model wrote it. Results are probabilities, not proof.
How pricing works
Billed per word or in credits per number of words, usually inside a monthly plan with an API add-on. We list the price for 1,000 words on the cheapest plan that includes API access.
We compare everything in one unit: USD per 1K words.
Typical uses
- Checking student essays and assignments
- Screening submitted articles and reviews
- Spotting generated spam and fake reviews
- Auditing content bought from writers or agencies
- Research on how much web content is generated
What to compare
- Accuracy and false-positive rate on human writing
- Sentence-level highlighting
- Languages
- Plagiarism checking in the same call
- Minimum text length for a reliable score
Watch out for
- False positives happen, especially for non-native writers and very formal text; never treat a score as proof on its own.
- Lightly edited or paraphrased model output is much harder to detect.
- Short texts give unreliable scores.
All 4 APIs, cheapest first
Free to browse| API | $ / 1K words | Sentence highlights | Plagiarism check | Names the model | Quality | Price data | Compare |
|---|---|---|---|---|---|---|---|
| Copyleaks AI Detector Copyleaks | $0.0266 | Yes | — | — | – | Unverified sample | |
| Sapling AI Detector API Sapling | $0.03 | Yes | — | — | – | Verified Oct 18, 2026 | |
| Winston AI detection API Winston AI | $0.09 | Yes | — | — | – | Unverified sample | |
| Originality.ai AI detector API Originality.ai | $0.119 | Yes | Yes | — | – | Verified Oct 18, 2026 |
Questions
- What is the cheapest API for ai text detection?
- Sapling AI Detector API from Sapling at $0.03 per 1K words, verified Oct 18, 2026. Proxlai ranks 2 verified offerings in this market in the same unit.
- How is API pricing for ai text detection compared?
- Billed per word or in credits per number of words, usually inside a monthly plan with an API add-on. We list the price for 1,000 words on the cheapest plan that includes API access. Proxlai converts every offering to one unit, USD per 1K words, so prices can be ranked side by side.
- How current are these prices?
- Each price shows the date it was last checked against the provider's own pricing page and links to it. In this market, prices were verified Oct 18, 2026. Sample prices that have not been checked yet are left out of this summary.