🆚 Altcha vs. Friendly Captcha

Type

Captcha service
Captcha service

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.

Friendly Captcha is a European captcha service that protects websites from bots and automated abuse while prioritizing user privacy, security, and accessibility.

It uses a proof-of-work approach that runs in the background without image challenges or tracking cookies, complies with GDPR by avoiding personal data collection, works without user interaction in most cases, and supports WCAG accessibility requirements.

Headquarters

Brno, Czech Republic
Woerthsee, Germany

Website

Pricing

Free version ✔️ Open source
ALTCHA Sentinel €99+/month
Free version ✔️ Non-commercial use, 1K requests/month
Starter (1 domain, 1K requests) €9/month
Growth (5 domains, 5K requests) €39/month
Advanced (50 domains, 50K requests) €200/month
Enterprise Custom

Categories

Captchas › Rank #6
Captchas › Rank #5
Spam Protection › Rank #9
Spam Protection › Rank #8

Popularity

Determined by the number of sites using each technology.

The Friendly Captcha service is 1.7 times more popular than Altcha.
Total websites

Market share

Captchas
Spam Protection

Popularity by country

Determined by the number of sites detected from each country.

Friendly Captcha is more popular in Germany, Austria, and the Netherlands, while Altcha is more popular in France, the United States, and the United Kingdom.
Germany
Austria
France
Netherlands
Switzerland
United States
United Kingdom
Sweden
Spain
Czech Republic

Awards

Popularity by domain category

Determined by the number of sites in each category.

Friendly Captcha is more popular among sites focused on business, marketing and merchandising, and online shopping, while Altcha is more commonly used on real estate, travel, and general news sites.
Business
Marketing/Merchandising
Online Shopping
Finance/Banking
Health
Education/Reference
Internet Services
Non-Profit/Advocacy/NGO
Real Estate
Software/Hardware

Top sites

Top-ranked sites that use these technologies.

Name
Rank
#5,726
#15,520
View more ➝
Name
Rank
xvideos.com
#59
xnxx.com
#99
xvideos.es
#629
xnxx.es
#639
xnxx-arabic.com
#709
View more ➝

See also

🗃️ About This Data