MTcaptcha
Enterprise Captcha solutions
18 Alternatives To MTcaptcha
Akismet
Akismet is a spam fighting service that protects millions of WordPress sites from comment and contact form spam.
Confident Captcha
Confident Technologies provides free CAPTCHA security software called Confident CAPTCHA, a picture…
FeedCaptcha
FeedCaptcha is a new captcha system, easy to integrate and with meaning for your product.
GeeTest CAPTCHA
GeeTest protects your websites, mobile Apps and APIs from bot threats.
Humans Not Invited
CAPTCHA that filters out humans and only lets programs pass
Metal Captcha
A captcha form for metal fans
Mollom
Mollom is a freemium web service to get rid of spam, unwanted content and fake users on your…
Negative Captcha
A plugin to make the process of creating a negative captcha in Rails much less painful
NoMoreCaptchas
What Does NoMoreCaptchas Do?
PHPMailer
Email sending library for PHP.
Sblam!
Open-source implementation of server-side spam filtering of blog comments and forum posts.
Securimage
Securimage is a script for generating complex images and CAPTCHA codes to protect forms from spam…
Sumo
Free tools to grow your email list.
UniqPin
UniqPin is a free for non-commercial use service which destiny improve ability of interfaces detect…
Virusdie
All-in-One cloud-based, simple, powerful and gorgeous website security tools built for everyone.
hCaptcha
Do you use a captcha to keep out bots? hCaptcha is a drop-in replacement for reCAPTCHA that earns website owners money and helps companies get their data labeled.
phpformmailer
Easy to use - Nothing stupid your visitors have to type before the form submits.
reCAPTCHA
reCAPTCHA is a free security service that protects your websites from spam and abuse.