PHP Captcha Script: Securimage
Securimage is an free PHP captcha script used for protecting web forms from spam and abuse.
It can be easily installed and very well documented.
Different than the famous reCAPTCHA, which is web-based, Securimage is a downloadable solution that requires PHP and GD library to work.
Some feature of this captcha solution:
- Show an image in just 3 lines of code
- Validate submitted entries in less than 6 lines of code
- Customizable code length
- Choose the character set
- TTF font support
- Use custom GD fonts when TTF is not available
- Easily add background images
- Multi colored, angled, and transparent text options
- Arched lines through text
- Generates audible CAPTCHA files in wav format
- Use a word list for creating CAPTCHA codes
You can find a demo of the captcha here.