🆚 Altcha vs. Yidun Captcha
- 📈 Altcha is five times more popular than Yidun Captcha.
- 🌎 Altcha is more popular in Germany, France, and the United States.
- 🌍 Yidun Captcha is more popular in China and Hong Kong.
AltchaType
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.
Yidun is a captcha service provided by the Chinese company NetEase.
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.
- ⭐ 5th most popular in China in the Captchas category.
- ⭐ 6th most popular in China in the Spam Protection 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.
reCAPTCHA
hCaptcha
Cloudflare Turnstile
Friendly Captcha
Tencent Captcha🗃️ 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.