Sapling AI Detector for Developers: 8 Languages and a 200,000-Character Limit (2026)
Sapling's AI detector API: the eight languages and 200,000-character request limit on its agent page, eesel AI's plan prices, and the 97% figure that remains a vendor claim.
Verdict: Sapling is the one detector in this set that is built for developers first. Its API documentation is clear on languages and request size, and its enterprise security claims are stated on its own site. Its 97% detection figure is a vendor claim, and this article does not treat it as a measured result.
Source: Sapling’s pricing notes.
What the API page states
Sapling’s agent-facing page at sapling.ai/llms.txt lists the AI Detector API for English, Spanish, Portuguese, French, German, Italian, Dutch and Japanese. It says that non-English text is scored by a multilingual model, and it sets the maximum at 200,000 characters per request. The same page says the detector returns scores at the document, sentence and token level. Source: Sapling’s price guide.
The page also lists SDKs for JavaScript and Python, an MCP server for coding assistants, and a self-hosted deployment option. It links to security and HIPAA pages, which describe SOC 2 Type II and business associate agreement coverage, according to the page’s own summary.
Source: Sapling’s plan breakdown, checked 2026-10-14.
What the review says about price
eesel AI’s June 2026 review puts Sapling’s paid plans at $25 per month, or $12 per month billed annually, with 100,000 characters per query. It lists Enterprise from $15 per seat per month with a 10-seat minimum, and an API rate of $0.005 per 1,000 characters for the first 10 million characters a month. Source: Sapling’s tier list.
The review also gives Sapling’s free tier as 2,000 characters per query. Sapling’s agent page does not state a free quota, so the review and the vendor do not line up on this point. Check the current terms before you design a free-tier workflow. Source: Sapling’s cost roundup.
Source: eesel AI’s cost roundup, updated June 15, 2026.
The 97% figure is a vendor claim
eesel AI reports that Sapling claims a detection rate of 97% or more, with a false-positive rate under 3% on longer texts. The review marks that as the vendor’s claim, and its own table lists Sapling as not independently tested. This article keeps the same split: the 97% belongs to the vendor, and the review found no independent result to set beside it. Source: Sapling’s feature table.
The review also reports that Sapling names the models it retrains on, including GPT-5, Claude 4.5, Gemini 2.5, Qwen3 and DeepSeek-V3. That is a useful disclosure to ask for, but it is still the vendor’s statement about its own training.
Who should build on it
- Developers adding detection to a product, who need a documented request size, a language list and programmatic scores at the sentence and token level.
- Compliance teams who need a vendor with a published security page and a HIPAA page to review.
- Teams with multi-language text that fits the eight languages on the list. Check any other language on your own samples before you rely on it.
Who should look elsewhere
Individuals who want a free check on one document may find the free tier too small, since the review describes it as 2,000 characters per query. Writers and teachers who want a web interface may prefer a tool built around that workflow. Teams who need a published benchmark may want to compare Sapling with a vendor that cites one. Source: Sapling’s comparison page.
Before you build
Test the detector on a sample of your own text, both human and AI-generated, and record the results at the sentence level. Check that your longest document fits the 200,000-character limit, or split it. Confirm the plan that includes the rate limits and the data-retention terms you need. Ask for the current free quota in writing, since the sources disagree.
What this article cannot tell you
This article did not call the Sapling API, so it does not report measured latency, error rates or accuracy. The language list and request limit come from Sapling’s own page. The prices and the 97% figure come from eesel AI’s review. Our handling of vendor figures is explained on the method page. Source: Sapling’s product roundup.
FAQ
Which languages does Sapling's AI detector API support?
Sapling's agent page lists English, Spanish, Portuguese, French, German, Italian, Dutch and Japanese for the AI Detector API. Other languages are scored by a multilingual model, according to the same page.
What is the largest request Sapling's detector accepts?
Sapling's AI Detector API page gives a maximum of 200,000 characters per request. The same page says it returns document-, sentence- and token-level scores.
How much does Sapling cost?
eesel AI's June 2026 review lists Sapling Pro at $25 per month, or $12 per month billed annually, with 100,000 characters per query. It also lists an API rate of $0.005 per 1,000 characters for the first 10 million characters a month. The review gives the free tier as 2,000 characters per query, while Sapling's agent page does not state a free quota, so check the current terms.