Cog is a tool for comparing languages using lexicostatistics and comparative linguistics techniques. It can be used to automate much of the process of comparing word lists from different language varieties.


The goal of Cog is to provide a framework for experimenting with different techniques for language variety comparison. It is intended to be used iteratively: run a comparison, analyze the results, refine the process, run the comparison again, and so on. Most steps in the process can be tailored. It currently only supports a few comparison techniques, but we hope to include many more in the future.

Analyze quickly

Cog allows you to quickly produce results by automating many of the steps of the word list comparison process:

  • IPA-based segmentation: automatically splits words in to segments
  • Syllabification: automatically marks syllables
  • Stem identification: identifies prefixes and suffixes so that they can be ignored during comparison
  • Word alignment: aligns segments between word pairs
  • Sound correspondence identification: automatically identifies sound correspondences and the environments in which they occur
  • Likely cognate identification: provides various methods for identifying likely cognates
  • Lexical/phonetic similarity: calculates lexical/phonetic similarity for multiple language varieties


Cog allows you to visualize your results from many different perspectives. Cog will automatically generate the following types of visual representations:

  • Radial trees
  • Dendrograms
  • Network graphs
  • Similarity matrices
  • Geographical maps


System Requirements

Cog is currently only available on Windows.

Cog requires that the .NET Framework is installed. Remember to install all of the latest updates for the .NET Framework to ensure that Cog runs properly.


MIT license »


Cog 1.3.8 for Windows 7 and later EXE | 12.44 MB | 13 Oct 2023
Cog 1.3.7 for Windows 7 and later EXE | 12.43 MB | 28 Sep 2023
Cog 1.3.6 for Windows 7 and later EXE | 12.42 MB | 23 Feb 2021
Cog 1.3.5 for Windows 7 and later EXE | 12.43 MB | 14 Aug 2020
Cog 1.3.4 for Windows 7 and later EXE | 17.88 MB | 30 Sep 2019
Cog 1.3.3 for Windows 7 and later EXE | 8.15 MB | 23 Apr 2019
Cog 1.3.2 for Windows 7 and later EXE | 8.16 MB | 24 Sep 2018
Cog 1.3.1 for Windows 7 and later EXE | 8.16 MB | 22 Jan 2018
Cog 1.3.0 for Windows Vista and later EXE | 7.37 MB | 18 Dec 2015


The Cog Tutorial can help to get you started.

The Settings Reference provides more detailed information about the settings and techniques available in Cog.

Cog also includes help in the application, just hit the F1 key.


If you would like to report a problem or to request a new feature, you can create an issue in Cog’s issue tracker.

You can also send an email via the contact form below.


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