Chromas is a free trace viewer for simple DNA sequencing projects which do not require assembly of multiple sequences. Chromas has the following features:
- Opens .ab1 chromatogram files from Applied Biosystems DNA sequencers.
- Opens SCF and ZTR format chromatogram files created by other sequencers or retrieved from databases.
- Save in .scf or Applied Biosystems .ab1 format.
- Print a chromatogram with options to zoom or fit to one page.
- Automatic removal of low-quality sequence (when quality data is available) or vector sequences.
- Export sequences in plain text, FASTA, FASTQ, EMBL, GenBank or GCG formats, or formatted with base numbering for presentation.
- Copy the sequence to the clipboard in plain text, FASTA or FASTQ format for pasting into other applications.
- Reverse & complement the sequence and chromatogram.
- Search for subsequences by exact matching or optimal alignment.
- Display translations in 3 frames along with the sequence.
- Copy an image of a chromatogram section for pasting into documents or presentations.
- Batch processing, including format conversion, sequence export with vector removal, batch printing and batch export of raw data.
- Enhance .ab1 files using the PeakTrace RP component from Nucleics Pty Ltd to improve peak readability and extract more high-quality bases.
Publisher’s description
What is Chromas?
Chromas is a free program for Windows from Technelysium Pty Ltd.
Installation and requirements
Official installers exist for 64-bit as EXE (Inno Setup). Installation asks for administrator rights. The installer supports unattended (silent) installation.
Popularity and file types
The Chocolatey package has been downloaded 3,733 times. On Windows it registers 3 file types, including .ab1, .scf and .ztr.
Pros / Cons
Pros
- Free to use
- Documented silent install
Cons
- No native ARM64 build
- Installation needs administrator rights
- No update for more than a year
In short: Chromas is a free Windows tool for 64-bit PCs. Updates have slowed down. Administrators can deploy it unattended.
Is Chromas safe to download?
- The file is served by technelysium.com.au, the publisher’s own domain
- The download link uses HTTPS
- A SHA256 hash is published, so you can verify the file:
3EEDBC3466EBC916EADB09388C3F76ADFC7C30A97BB6BDD254BF2DCC0052D95D· Open the VirusTotal report for this hash - The link answered when we last checked it (October 22, 2026)
- ExeAtlas does not host, wrap or modify installers
Related guide: How to check a file’s SHA256 hash on Windows
Recent versions
All 1 versions ›| Version | Date | Size | Files |
|---|---|---|---|
| 2.6.6Latest | February 14, 2025 | — | 64-bit EXE (Inno Setup) |
Install from the command line
Silent install ›winget install --id Technelysium.Chromas -echoco install chromas -yscoop install extras/chromasChromas266Setup.exe /VERYSILENT /SUPPRESSMSGBOXES /NORESTART /SP-Related guide: How to use winget: install and update apps
Information
- Publisher
- Technelysium Pty Ltd
- Licence
- Freeware
- Price
- Free
- Requires
- Windows 11 / 10
- Architecture
- 64-bit
- Installer
- EXE (Inno Setup)
- Version
- 2.6.6
- Released
- February 14, 2025
- Added to the catalogue
- February 14, 2025
- Versions listed
- 1
- Chocolatey downloads
- 3,733
- Website
- technelysium.com.au
- winget ID
- Technelysium.Chromas
- Chocolatey package
- chromas
- Scoop package
- extras/chromas
File types it opens (3)
Ratings and reviews
No reviews yet. Be the first to rate it.
Frequently asked questions
Is Chromas free?
Yes. Chromas is free to use.
Is Chromas safe to download?
The download comes from technelysium.com.au, which belongs to the publisher; ExeAtlas does not host or change the file. Compare its SHA256 hash with the one shown here, or open the VirusTotal report for that hash.
How do I install Chromas with winget?
Open PowerShell or Windows Terminal and run the winget command shown on this page. winget downloads the official installer and checks its SHA256 hash before running it.
Can Chromas be installed silently?
Yes. The silent install page lists the exact command for each installer.
Does Chromas run on ARM (Windows on Arm)?
There is no ARM64 build; Windows 11 on Arm can run the 64-bit version through emulation.