cap — modern, lightning-quick PoW captcha

cap is a lightweight, modern open-source CAPTCHA alternative designed using SHA-256 PoW.

try cap →

why Cap?

⚡️ 250x smaller than hCaptcha
cap's widget library is extremely small, only 12kb minified and brotli'd.
🔒️ Private
cap's usage of proof-of-work eliminates the need for any tracking, fingerprinting or data collection.
🌈 Fully customizable
cap is self-hostable so you can customize both the backend & frontend — or you can just use CSS variables
🤖 PoW-based
cap uses proof-of-work instead of complex puzzles, making it easier for humans and harder for bots
🧩 Standalone mode
cap offers a standalone mode with Docker, allowing you to use it with languages other than JS.
💨 Invisible mode
cap can run invisibly in the background using a simple JS API.
☁️ Floating mode
floating mode keeps your CAPTCHA hidden until it's needed
🌳 Fully FOSS
completely open source under the Apache license 2.0 license

Name		Name	Last commit message	Last commit date
Latest commit History 121 Commits
.github		.github
assets		assets
demo		demo
docs		docs
server		server
solver		solver
standalone		standalone
widget		widget
.gitignore		.gitignore
CNAME		CNAME
LICENSE		LICENSE
LICENSE.md		LICENSE.md
README.md		README.md
TODO.md		TODO.md
package.json		package.json