Plagiarism: Crot Plagiarism Checker

Maintained by Picture of Sergey Butakov Sergey Butakov
This FREE plugin is aimed at digital plagiarism detection: it uncovers assignments copied from peers at the same institution. The module is language independent. Maintainer: Sergey Butakov More information:
65 sites
7 fans
Moodle 2.3, 2.4, 2.5

Block is based on document fingerprinting technologies for pair-wise document comparison.

Please note that as of August 01, 2012 the block does not perform global / Internet search due to monetization of Bing search engine API.


A distinctive feature of this plug-in is that all local checkups are happening on your Moodle server without sending any documents outside. Thus, in contrast to other available solutions, the plug-in does not impose any issues related to student intellectual property protection. 


This module is the successor of  Crot for Moodle block: This version is tailored for the plagiarism API in Moodle 2.x.

This is standalone module that doesn't require a connection to the external plagiarism detection service. 

Maintainers: Sergey Butakov, Svetlana Kim

More information:


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Picture of Sergey Butakov
Sergey Butakov (Lead maintainer)
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  • Picture of Blair F.
    Fri, 18 Sep 2015, 1:07 AM
    Any plans to update this for newer Moodle versions? I tried installing in 2.8 and get the following errors. Unfortunately, I'm now stuck on the plugins check page. Whoops. Good thing it's our test site. smile

    Coding error detected, it must be fixed by a programmer: Invalid table name {plagiarism_crot_submission_pair}: name is too long. Limit is 28 chars.

    Debug info:
    Error code: codingerror
    Stack trace:

    line 287 of /lib/ddl/sql_generator.php: coding_exception thrown
    line 209 of /lib/ddl/mysql_sql_generator.php: call to sql_generator->getCreateTableSQL()
    line 248 of /lib/ddl/sql_generator.php: call to mysql_sql_generator->getCreateTableSQL()
    line 409 of /lib/ddl/database_manager.php: call to sql_generator->getCreateStructureSQL()
    line 364 of /lib/ddl/database_manager.php: call to database_manager->install_from_xmldb_structure()
    line 502 of /lib/upgradelib.php: call to database_manager->install_from_xmldb_file()
    line 1628 of /lib/upgradelib.php: call to upgrade_plugins()
    line 434 of /admin/index.php: call to upgrade_noncore()
  • Picture of Sergey Butakov
    Fri, 18 Sep 2015, 1:27 AM
    There is an easy fix for that. just check forum
  • Picture of Blair F.
    Fri, 18 Sep 2015, 1:47 AM
    Sorry, but I don't see any "easy" fix in the forum (which, for those trying to find it is here: . The only thing I found required changes to xmldb_table.php . Was that what you were referring to? That's not something I have access to, so I guess this plugin is not usable for us, unfortunately. I'll keep my eyes open for an official update to the plugin.
  • Picture of Mikael Wazikov
    Wed, 28 Oct 2015, 10:50 PM
    I'm trying to choose between Crot and Unplag Plagiarism plugin for Moodle. Does Crot use only Bing search engine? On is said that Unplag checks against Google and Yahoo.
  • Picture of Mariya Kulygina
    Mon, 16 Nov 2015, 6:19 PM
    Will this plugin work for the workshops, or is it made only for assignments?
  • Picture of Farhat Ali
    Wed, 18 May 2016, 5:29 PM
    Thank you for contribution. I've some problem when I created an account key is not displaying.

    Farhat Ali
  • Picture of Claite Wilson
    Mon, 31 Oct 2016, 6:15 PM
    a great plugin...which combined with essay samples would make it easier for any student write plagiarism free, original essays
  • Ricardo Caiado
    Mon, 20 Feb 2017, 8:27 PM

    Is there any chance of this plugin being upgraded to Moodle version 3.2?

  • Picture of Janey Crosby
    Tue, 25 Apr 2017, 3:59 PM
    Wow, I've never heard about this tool. I personally use this plagiarism checker because it accepts all text formats. I'll try the suggested one smile
  • Picture of reginald surict
    Thu, 19 Oct 2017, 6:02 PM
    Cool. That's exactly what I need as I plan to order paper from and I am interested in having my paper unique and plagiarism free.
  • Picture of Krisha Moeller
    Sat, 2 Dec 2017, 3:41 AM
    I'm trying to install this plugin, but I keep getting the following error message:

    Validating plagiarism_crot ... Error
    [Error] Plugin does not declare its component name [null]
    Installation aborted due to validation failure

    What should I do? Thank you for your help!
  • Picture of Rayn Podolskiy
    Wed, 27 Dec 2017, 8:55 PM
    thanks, it will help me check out one essay writing service uk, where I often make orders
  • Picture of Darryl Wood
    Tue, 30 Jan 2018, 6:20 PM
    Thanks a lot for this great tool. Now I can check my student's narrative essays for plagiarism. I hope you still support this project.
  • Picture of Katia Gratz
    Tue, 6 Feb 2018, 6:40 PM
    This is one more marvelous site page that has indicated me amazing assets which incorporates instructional exercises and materials to the significant class of theme subject. So I propose you by and by experience these Friv wonderful assets to learn something which is exceptionally helpful for everybody out there. Thanks so much!
  • Ricardo Caiado
    Sun, 18 Mar 2018, 4:40 AM
    Any updates do Moodle 3.4?

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