Alternatives to Cap

CAPTCHA	Open-source	Free	Private	Fast to solve	Easy for humans	Small error rate	Checkpoints	Widget support	GDPR/CCPA Compliant	Customizable	Hard for bots	Easy to integrate
Cap	✅	✅	✅	✅	✅	✅	✅	✅	✅	✅	🟨	✅
Cloudflare Turnstile	❌	✅	🟨	🟨	✅	❌	🟨	✅	✅	❌	🟨	✅
reCAPTCHA	❌	🟨	❌	✅	❌	🟨	❌	✅	🟨	❌	❌	✅
hCAPTCHA	❌	🟨	🟨	❌	❌	🟨	❌	✅	🟨	❌	🟨	✅
Altcha	✅	✅	✅	✅	✅	✅	❌	✅	✅	✅	🟨	🟨
FriendlyCaptcha	❌	❌	✅	🟨	✅	✅	❌	✅	✅	✅	🟨	🟨
MTCaptcha	❌	🟨	🟨	❌	❌	🟨	❌	✅	✅	❌	❌	🟨
GeeTest	❌	❌	❌	🟨	🟨	🟨	❌	✅	✅	❌	🟨	🟨
Arkose Labs	❌	❌	❌	❌	❌	❌	❌	❌	✅	🟨	❌	❌

Note

"Hard for bots" does not consider commercial solvers like BrightData, as I cannot verify their legitimacy myself.

All alternatives

Cloudflare Turnstile

Cloudflare Turnstile is a great alternative to Cap, but unfortunately it is known for having an extremely high error rate and relies a lot on fingerprinting, especially for users using private browsers such as Brave or Librewolf. Additionally, unlike Turnstile, Cap is open-source and self-hosted.

reCAPTCHA

Not only is Cap significantly smaller and faster than reCAPTCHA, it's open-source, fully free and is significantly more private. Cap doesn't require you to check traffic signs or solve puzzles, and it doesn't track users or collect data.

Additionally, reCAPTCHA v2 challenges can be solved trivially by multi-modal LLMs, especially audio challenges.

hCAPTCHA

Pretty much the same as reCAPTCHA, however while it's significantly more resistant to bots, it is also extremely annoying for users to solve when prompted with a visual challenge compared to reCAPTChA. It also has a significantly bigger bundle size.

Additionally, hCAPTCHA is prohibitively expensive for many users, while Cap is completely free and self-hosted.

Altcha

Cap is slightly smaller than Altcha and includes extra features like progress tracking, and a simpler dashboard. if you don't need these, Altcha is a still a solid choice.

mCAPTCHA

While mCAPTCHA is similar to both Cap and Altcha, it seems to have been deprecated and has a significantly larger widget bundle.

FriendlyCaptcha

Unlike FriendlyCaptcha, Cap is completely free and self-hosted (FriendlyCaptcha is €39/month for 5k requests and 5 domains).

MTCaptcha

Cap is more lightweight, doesn't rely on users solving an image puzzle that LLMs and OCR can easily solve and is open-source and self-hostable.

GeeTest

Cap is free, self-hosted and open-source, while GeeTest is a paid service. Cap is also more private and doesn't rely on tracking users or collecting data. GeeTest is also china-based, which may be a concern for some users.

Arkose Labs

Arkose's CAPTCHA is known for being hard, slow and annoying for humans to solve. It is also a paid, closed-source service.

Anubis

While Anubis is a great scraper deterrent and uses the same proof-of-work concept as Cap, it uses a low difficulty by default (which is easier for bots to solve) and does not provide a standalone CAPTCHA.