TUR.ID. Example

TURing IDentification test to distinguish between humans and computers

A valid and funnier alternative to visual CAPTCHAs, without any accessibility issue.

Please complete the following text with the correct words.

Rome became the pre-eminent Christian city (vis-a-vis  and
Alexandria, and later  and Jerusalem) based on the tradition
that Saint Peter and Saint Paul were martyred in the city during the 1st
century, coupled with the city's political importance
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Take another TUR.ID. test


Download TUR.ID. implementation (PHP) v 0.1 by Daniele C. (aka legolas558)


This example uses (randomly) the following sources to create TUR.ID. tests:

Your users are unlikely to understand and complete the Divina Commedia's or the Paradise Lost's texts, so it is strongly suggested to use a wide range of common texts (e.g. from online newspapers, if you have the permission) to implement your tests.

The class is enough extensible and powerful (it is initalized passing a custom callback to the constructor) to allow the usage of any custom source for the random senteces:

You can of course customize everything else, the number of replaced words and the number of alternatives.

Give a look to the current source code (SVN)


TUR.ID. is free software, released under the GNU/LGPL license (read it)

If you are using TUR.ID. in your software a line of credits would be nice to be seen.


Please use the SourceForge.net based forums to discuss about TUR.ID. and related topics.

The SF.net project page contains also other open source project facilities

TUR.ID. is Copyright © 2007 by legolas558
This software is licensed under the GNU/LGPL license