BED File Format

A BED file (.bed) is a tab-delimited text file that defines a feature track. It can have any file extension, but .bed is recommended. The BED file format is described on the UCSC Genome Bioinformatics web site: Tracks in the UCSC Genome Browser ( can be downloaded to BED files and loaded into IGV.



IGV does not currently support multiple track lines in a single BED file  

Zero-based index: Start and end positions are identified using a zero-based index. The end position is excluded. For example, setting start-end to 1-2 describes exactly one base, the second base in the sequence.

Display settings: To modify IGV's default display settings for the BED data, include a track line in the file.

GFF tag option (Version 2.0 only): By adding a #gffTags line to the beginning of a .bed file, you can add GFF3-style attributes to the Name field (column 4) of a BED file which are displayed in the popup text.  Note that the Name field is special: it will become the display name. See the GFF3 specification, column 9 for more details.