13 April 2005

Captcha Guidelines

Posted under: at 23:00


If it is not possible to avoid captcha entirely, please at least do it right!

  • Do not mix letters and numbers. It is hard to distinguish O and 0, 1 and l or in some cases even G and 6 or 9 and g. Please use either letters or numbers exclusively.
  • Do not mix uppercase and lowercase letters, or don’t be sensitive to case. It is hard to distinguish O and o, C and c, s and s, etc. Especially when the letters are twisted, then it is no longer possible to depict case from the letter height alone.
  • Do not use random words, do use common dictionary words. It is a lot easier the user. It is not that people will brute force your captcha. If some people do, simply give them a new captcha for them to break.

Thanks for your cooperation :).

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