# Capcat, the invisible open-source CAPTCHA No Google, no ad tracking, no image puzzles. Proof of work runs silently in the browser — sign up and protect your forms and APIs in 5 minutes. - [Get started](https://capcat.ai/guide/index.md) - [Live demo](https://capcat.ai/demo/index.md) - [Open console](https://console.capcat.ai) > Give it a click — this talks to the real production service. Switch the style and the widget adapts on its own. ## Why Capcat: Verification, without giving up privacy Single-use computational proofs are the default. Optional Account Defense processes bounded, signed security aggregates without uploading raw trajectories or building advertising or cross-site profiles. ### 01 / Data minimization The widget uses no advertising cookies and creates no cross-site identity. When risk evaluation is enabled, collection is capped at 15 seconds and 128 samples; raw coordinates and event sequences never leave the browser. ### 02 / Invisible to users Users just tick a checkbox while a SHA-256 proof of work completes silently in the background — no more squinting at traffic lights and crosswalks. ### 03 / Fully hosted Nothing to deploy or operate: create a site in the console to get your keys, global edge nodes respond nearby, and domain binding plus usage dashboards work out of the box. ### 04 / reCAPTCHA-compatible The siteverify endpoint is compatible with the reCAPTCHA / hCaptcha API — migrate by changing one URL on the server and swapping in the Capcat widget on the frontend. --- - [Docs](https://capcat.ai/guide/index.md) - [Live Demo](https://capcat.ai/demo/index.md) - [About](https://capcat.ai/guide/about.md) - [Console](https://console.capcat.ai) - [中文](https://capcat.ai/cn/index.md) Built on [Cap](https://github.com/tiagozip/cap) (Apache 2.0) · © 2026 capcat.ai