Windows
Compatible applications
Quick Facts
Basic information about this file format
Extension
.BAM
File Type
Binary Alignment Map
Category
Data
Best first step
Use compatible software
Quick Summary
A practical overview of the .bam file format
The BAM (Binary Alignment Map) file format is the compressed binary version of the Sequence Alignment Map (SAM) format, designed specifically for storing large-scale biological sequence alignments. In the field of bioinformatics, researchers use BAM files to manage the output of sequence aligners t…
File extension
.BAM
File type
Binary Alignment Map
Category
Data
Recommended action
Open with a trusted compatible app
How to open a .bam file
Start with a trusted app that supports this format
- Check the file extension carefully and confirm that the file name really ends with .bam.
- Use software that supports this file type. If one app does not work, try another compatible program for the same platform.
- Update the application if the file was created by a newer version of the software.
- Scan files from unknown sources before opening them, especially documents, archives, scripts, installers, and executable files.
What is a .bam file?
File extension details and usage information
The BAM (Binary Alignment Map) file format is the compressed binary version of the Sequence Alignment Map (SAM) format, designed specifically for storing large-scale biological sequence alignments. In the field of bioinformatics, researchers use BAM files to manage the output of sequence aligners that map raw sequencing reads—typically from Next-Generation Sequencing (NGS) platforms—to a reference genome. Because raw genomic data can be incredibly voluminous, the BAM format employs BGZF (Blocked GNU Zip Format) compression to minimize storage space while maintaining high performance. One of the most significant advantages of the BAM format is its support for indexing; when accompanied by a .bai index file, software can perform rapid random access to specific genomic coordinates without needing to parse the entire dataset. Each record in a BAM file includes the read name, sequence, quality scores, mapping position, and a CIGAR string representing the alignment's structural details. This format is essential for downstream analysis tasks, including variant calling, structural variation detection, and visualization in genome browsers, making it a cornerstone of modern genomic research.
Software Compatibility
Programs that may open or work with .bam files
macOS
Compatible applications
Linux
Compatible applications
Mobile
Mobile applications
Can .bam files be converted?
Options for saving or exporting this file to another format
In many cases, a .bam file can be converted by opening it in compatible software and using an option such as Save As, Export, or Convert. The available output formats depend on the file type and the application used.
- Use the original software that created the file when possible.
- Check whether the application supports exporting to common formats.
- Be careful with online converters when working with private, business, or sensitive files.
- If conversion fails, the file may be corrupted, incomplete, encrypted, or not actually a .bam file.
Why can't I open a .bam file?
Common reasons this file type may not open correctly
Wrong software
The file may require a specific program that supports the .bam format.
Incorrect extension
The file extension may have been renamed manually, even though the actual file format is different.
Corrupted file
The file may be incomplete, damaged during download, or transferred incorrectly.
Outdated app
Your software may need to be updated before it can open newer versions of this file format.
Frequently Asked Questions
Common questions about .bam files
To open a .bam file, use software that supports this file format.
- IGV (Integrative Genomics Viewer)
- Tablet
- Samtools (via WSL)
- Golden Helix GenomeBrowse
- Samtools
Open the file in compatible software and look for options such as Save As, Export, or Convert. If no export option is available, the file may require a specialized converter or the original application that created it.
- Verify that the file extension is correct.
- Install or update compatible software.
- Try another application that supports this format.
- Check whether the file is corrupted, incomplete, or encrypted.
A file extension alone does not guarantee whether a file is safe or unsafe. Only open files from trusted sources, scan unknown files before opening them, and be especially careful with executable, script, archive, and document files.
File safety tips
Use caution with unknown files
Only open files from trusted sources. Before opening a .bam file, scan it with antivirus software, verify that the file extension is expected, and avoid running unknown executable, installer, macro-enabled document, or script files.