AI Detector API vs GPTZero

TL;DR

• GPTZero is consumer-first. Polished web UI, dashboards, integrations, school-friendly reporting. API is a secondary product.
• AI Detector API is API-first. No dashboard cruft. Clean JSON, predictable rate limits, sentence-level scores by default.
• Pricing: GPTZero starts at $9.99/mo (Essential) or $14.99/mo (Premium). AI Detector API starts free (1,000 req/mo), Pro at $49/mo (50,000 req).
• For developers: AI Detector API is the simpler integration. GPTZero's API documentation is thinner.
• For schools / non-developers: GPTZero's dashboard is hard to beat.

Feature-by-feature comparison

When to pick AI Detector API

You're building a product that needs detection as a feature. A content moderation pipeline, an LMS, an editorial workflow, an SEO QA tool. You want a clean REST API, no sales call, and to start small.

When to pick GPTZero

You're a school administrator, journalist, or consumer-facing publisher who wants a polished web app with reporting, history, and team collaboration. Or you specifically need GPTZero's brand recognition for procurement reasons.

How the two products price their API

GPTZero ships a consumer subscription first, with the API bolted on as a feature of the Premium plan and above. The Essential tier at $9.99/month gives you a small monthly word allowance (around 150,000 words). Premium at $14.99/month raises the limit, and dedicated API plans start in the $30 to $50 range depending on volume. Pricing is by word, so long submissions burn quota faster than short ones.

AI Detector API takes the opposite shape. The free tier is 1,000 requests per month, no credit card, billed by request rather than by word. A 5,000 word essay and a 100 word tweet cost the same: one request. The Pro tier at $49/month covers 50,000 requests, and there is no minimum commitment.

The per-request model is friendlier when you cannot predict document size. A schools customer who scans full essays and a trust and safety customer who scans short forum posts get predictable monthly bills with AI Detector API, while GPTZero bills will move with content length.

Real latency and accuracy

AI Detector API targets sub-300ms median response on the detect endpoint, with p95 around 450ms. GPTZero's API has historically run 1 to 2 seconds for typical inputs and longer for long documents, partly because their pipeline is tuned for the web product first.

Accuracy is harder to compare cleanly. Both products publish marketing accuracy numbers in the 99 percent range against their own benchmarks. In practice, accuracy depends heavily on which language models you are trying to detect and how much editing the human did after generation. We test both detectors quarterly against fresh output from GPT, Claude, Gemini, Llama, and DeepSeek, and we publish methodology notes when we ship a major model update.

What it actually takes to integrate

AI Detector API publishes a clean REST endpoint, an OpenAPI spec, and official SDKs for Python and JavaScript. The authentication is a bearer token. Most teams have a working integration in under 5 minutes. The signup page issues a key immediately on the free tier, no sales call required.

GPTZero's developer docs are thinner than the consumer product would suggest. The API works, but you will spend more time reading example code in their support center than with our docs. Their key model is also tied to the subscription, which means provisioning a key for a teammate involves an extra step inside the dashboard.

Migrating from GPTZero to AI Detector API

The request shape is similar enough that most teams can switch with a one-file change. Replace the host and the auth header. The response keys differ slightly: AI Detector API returns score in the 0 to 1 range and a sentence-level sentences array by default. If you were already reading per-sentence data from GPTZero, your downstream code should need only a field rename.

// Old (GPTZero)
const r = await fetch("https://api.gptzero.me/v2/predict/text", {
  headers: { "x-api-key": process.env.GPTZERO_KEY },
  body: JSON.stringify({ document: text }),
});

// New (AI Detector API)
const r = await fetch("https://api.aidetectorapi.com/v1/detect/", {
  method: "POST",
  headers: {
    "Authorization": `Bearer ${process.env.AIDETECTORAPI_KEY}`,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({ text }),
});

FAQ

Related reading

• Best AI Detector APIs in 2026. Compared & Tested
• AI Detection APIs: Features & Integration Guide
• Quickstart. Detect AI Text in 5 Minutes