🆚 Cap vs. Cloudflare Turnstile

Cap is an open-source, self-hosted reCAPTCHA alternative that verifies visitors without visual puzzles, tracking, or third-party services.

It uses a two-layer verification model that combines proof-of-work challenges accelerated with WebAssembly and Web Workers, including SHA-256 hashing and optional GPU-resistant time-locks.

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Cloudflare Turnstile is a user-friendly CAPTCHA alternative that verifies human visitors without requiring them to solve interactive puzzles or identify objects.

It works by running invisible background tests such as proof-of-work calculations and checks for browser quirks to analyze the visitor's environment and behavior, supports Private Access Tokens (PATs) to validate devices without tracking, and offers a free API.

Popularity

Determined by the number of sites using each technology.

• 🥈 Second most popular in Japan in the Spam Protection category.
• 🥈 Second most popular in Japan in the Captchas category.
• 🥈 Second most popular in Turkey in the Captchas category.
• 🥈 Second most popular in Hungary in the Captchas category.
• 🥈 Second most popular in Slovakia in the Captchas category.

Top sites

Top-ranked sites that use these technologies.

Compare alternatives

Technologies with similar characteristics.

• Cap vs. reCAPTCHA
• Cap vs. hCaptcha
• Cap vs. Yandex SmartCaptcha
• Cap vs. Friendly Captcha
• Cap vs. Altcha

• Cloudflare Turnstile vs. reCAPTCHA
• Cloudflare Turnstile vs. hCaptcha
• Cloudflare Turnstile vs. Yandex SmartCaptcha
• Cloudflare Turnstile vs. Friendly Captcha
• Cloudflare Turnstile vs. Altcha

• Cap technology profile

• Cloudflare Turnstile technology profile
• Cloudflare company profile