🆚 Altcha vs. Cloudflare Turnstile
- 📈 Cloudflare Turnstile is much more popular than Altcha.
- 🌍 Cloudflare Turnstile is more popular in all countries.
- ⭐ Altcha is particularly popular in Germany.
Type
About
Altcha is an open-source, privacy-first, self-hosted captcha alternative that uses a proof-of-work mechanism to protect websites, APIs, and online services from spam and unwanted content.
It performs client-side computational challenges based on hashing and memory-hard algorithms such as Argon2 and Scrypt, adds headers and signatures for verification, operates without cookies, fingerprinting, or external requests, and supports more than 50 languages to meet accessibility and privacy requirements.
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.
Headquarters
Pricing
Categories
Popularity
Determined by the number of sites using each technology.
Market share
Popularity by country
Determined by the number of sites detected from each country.
Awards
- ⭐ 4th most popular in France in the Captchas category.
- ⭐ 4th most popular in the United Kingdom in the Captchas category.
- ⭐ 4th most popular in the Czech Republic in the Captchas category.
- ⭐ 4th most popular in Poland in the Captchas category.
- ⭐ 5th most popular in Germany in the Captchas category.
- 🥈 Second most popular in Japan in the Captchas category.
- 🥈 Second most popular in Japan in the Spam Protection 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.
Popularity by domain category
Determined by the number of sites in each category.
Top sites
Top-ranked sites that use these technologies.
Compare alternatives
Technologies with similar characteristics.
See also
🗃️ About This Data
- We evaluate the popularity of technologies based on the number of websites where we detect their usage.
- Technologies without a detectable web footprint, and those we do not track, are not reflected in the calculated market share.
- This report is based on the analysis of 3,511,995 websites.
- Statistics were last calculated on .
- For more details, see our methodology and disclaimer.
hCaptcha