Open BAM files in your browser
SAM's compressed binary twin, how sequencing alignments are kept and shared. Open a BAM right here as a row for each read. Nothing leaves your device.
Or drop it anywhere on this page
What you'll see
Your alignments open as a row for each read, the first rows on show while the rest are read.
- A row for each read • Position, CIGAR, mate and tags
- Sort and filter • Counts for every column
- Flags in words • References, read groups and programs
- Export • Save as CSV, Excel, JSON or Parquet
About BAM
BAM came with SAM in 2009, made by Heng Li and the 1000 Genomes Project for SAMtools, and it's how aligned reads are kept: sequencing centers, GATK and genome browsers like IGV work from BAM files, usually sorted by position with a .bai index beside them.
A BAM is SAM packed into binary records, each read's letters 4 bits apiece, and compressed in BGZF, gzip blocks of at most 64 KB each, so a tool can unpack just the block it needs. Its header holds the SAM header's text and the list of references.
Filepeek unpacks it in your browser a block at a time and shows each read as a row like a SAM's, its flag spelled out in words, to sort, search and filter like any table. Show details lists the references, read groups, samples and programs, and Export saves the rows as CSV, Excel, JSON or Parquet.
Binary Alignment/Map
.bam
Format
- MIME type
- application/x-bam
- Made by
- Heng Li and the 1000 Genomes Project, for SAMtools
- Released
- 2009
Inside the file
- Compressed
- BGZF, gzip blocks of up to 64 KB
- Header
- The SAM header and the references
- Each read
- A binary record, letters 4 bits each
- Index
- A .bai or .csi file beside it
Opens in every browser
Filepeek opens BAM files of any size in Chrome, Edge, Firefox and Safari, a block at a time, so the first reads show at once. On their own, browsers download them.
- YouChromeOpens through Filepeek
- YouEdgeOpens through Filepeek
- YouFirefoxOpens through Filepeek
- YouSafariOpens through Filepeek
Apps that open BAM
- WindowsNo app built in reads it • IGV and samtools do
- MacNo app built in reads it • IGV and samtools do
- iPhone and iPadNo app opens it
- AndroidNo app opens it
Questions
How do I see what's in a BAM file?
Drop it here. Each read shows as a row with its reference, position, CIGAR, letters and tags, as samtools view prints them on a computer with SAMtools.
Do I need the .bai file?
No. The index lets genome browsers jump to a region, and Filepeek reads the reads in order without it. A .bai on its own holds no reads.
Can I search the reads?
Yes. Search finds a read by its name or its letters, and Filter narrows any column, like Reference to one chromosome or MAPQ to reads above 30.
Can I turn a BAM into a spreadsheet?
Yes. Choose Export, then Save as CSV, Excel, JSON or Parquet, with a row for each read and its fields.