Artemis Comparison Tool (ACT)


ACT is a Java application for displaying pairwise comparisons between two or more DNA sequences. It can be used to identify and analyse regions of similarity and difference between genomes and to explore conservation of synteny, in the context of the entire sequences and their annotation. It can read complete EMBL, GENBANK and GFF entries or sequences in FASTA or raw format. 

Related Software

Two separate ACT-related web applications have been developed. 

  • WebACT was developed at Imperial College, and allows users to generate comparisons from their sequence files or use a set of pre-computed comparisons. All comparison files can be downloaded for local use or launched in ACT. 
  • DoubleACT was developed by Anthony Underwood and Jonathan Green at the Public Public Health England and allows you to paste or upload sequences to generate ACT comparison files.

Download and Installation

ACT needs a recent version of Java v1.6 or higher.

The latest release of ACT can be downloaded from our ftp site:

It can also be launched with Java Web Start:

Launch with 512MB

Launch with 1024MB

Get Java WebStart

For older versions of the ACT software please see the ACT FTP site.

For further download and installation instructions, please see the ACT manual and our GitHub page.

Notes for Download

Note for MacOSX Yosemite (10.10): on the latest version of OSX, ACT mandatorily requires Java v1.6 to run. It will not run with later Java versions.

Note for MacOSX: occasionally a browser decides to display the contents of the .dmg.gz archive file rather than downloading it. If this happens hold down the <control> key and click on the download link. A popup menu should appear, containing several choices. One of the choices should be something like "Save Link As" (or perhaps "Download Link...", "Save Link to Desktop", or a variation on this theme). Select that option, and the archive file should be download correctly.

Note for Windows: you may need to shift-click on this link to download the file. Also please ensure that after downloading this file is called "act.jar" with no other hidden extensions. Some windows systems change the name so it looks like a zip file, if this happens then do not unzip it just rename it to "act.jar".

Learn and Support

For more information and advice on using this software please see the ACT manual and our GitHub page.

In addition, an email discussion list called artemis-users is available and posts to the list since September 2001 are archived at

License and Citation

ACT is available under GPL3.

If you make use of this software in your research, please cite as:

ACT: the Artemis Comparison Tool.

Carver TJ, Rutherford KM, Berriman M, Rajandream MA, Barrell BG and Parkhill

Bioinformatics (Oxford, England) 2005;21;16;3422-3
PUBMED: 15976072; DOI: 10.1093/bioinformatics/bti553


If you need help or have any queries, please contact us using the details below.

Our normal office hours are 8:30-17:00 (GMT) Monday to Friday.


  • ACT: the Artemis Comparison Tool.

    Carver TJ, Rutherford KM, Berriman M, Rajandream MA, Barrell BG and Parkhill J

    Bioinformatics (Oxford, England) 2005;21;16;3422-3

  • WebACT: an online genome comparison suite.

    Abbott JC, Aanensen DM and Bentley SD

    Methods in molecular biology (Clifton, N.J.) 2007;395;57-74

Tool type
  • Main ACT window showing a two sequence comparison.

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