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An independent captcha that does not feed any AI and takes arbitrary lists of words
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Emancipate yourselves from CAPTCHA slavery,

None but ourselves can free our web services!

Today is your day to let go of things that no longer serve you.


indyCaptcha is a minimal and independent C99 implementation of a CAPTCHA generator using configurable fonts and list of words. This software is a response to the growing adoption of Google's reCaptcha and its annoying usage to mock humans to prove they are not AI by training other AIs.


indyCaptcha was originally made in 2013 as an off-line and non-spying implementation to be used in the subscription mechanism of the Italian Pirate Party, subsequently published as a stand-alone portable software in 2018 following the inspiration given by reading James Swineson's comments on reCaptcha.

Further motivation to the development and adoption of this software can be found in the Algorithmic Sovereignty discourse.

Tech details

indyCaptcha only dependency is from libGD2, the aim is that of making it portable and embeddable into any platform (MS/Win, Apple/OSx, GNU/Linux, Android, iOS, nodeJS, WASM) and compilable as a fully static and isolated software that can be deployed on-chip (unikernel).


indyCaptcha is Copyright (C) 2013-2018 by foundation

Designed, written and maintained by Denis Roio

The painting "Holding Space" is by Adam Scott Miller.

Upcoming contributions will be listed here.

Permission is granted to copy, distribute and modify indyCaptcha in any context without fee, including a commercial application, provided that this notice is present in user-accessible supporting documentation.

This does not affect your ownership of the derived work itself, and the intent is to assure proper credit for the authors of indyCaptcha, not to interfere with your productive use of indyCaptcha. "Derived works" includes all programs that utilize indyCaptcha library. Credit must be given in user-accessible documentation.

This software is provided "AS IS." The copyright holders disclaim all warranties, either express or implied, including but not limited to implied warranties of merchantability and fitness for a particular purpose, with respect to this code and accompanying documentation.

If you have questions, ask. This license is in fact Apache 2.0 license reported below and in the LICENSE.txt file included in all distributions of indyCaptcha.

   Copyright 2013-2018 foundation, Amsterdam

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   See the License for the specific language governing permissions and
   limitations under the License. 
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