Illumina CASAVA base call data
File type: Various data file
A bcl file extension identifies base call data produced by Illumina sequencing workflows.
A bcl file belongs to the CASAVA software and contains data from sequencing reads.
Found 2 different file type records with the same bcl filename suffix.
File type category:
Various data file
Date updated: November 6, 2026
The bcl file extension is associated with CASAVA, an Illumina application that processes sequencing reads provided by RTA or OLB.
A bcl file is a binary sequencing-run file containing base calls and associated call data. CASAVA uses these files as input during its sequencing data-processing workflow.
CASAVA is legacy Illumina software, and BCL files are mainly encountered in older sequencing runs. The linked CASAVA software is available for Microsoft Windows.
Open the bcl file with CASAVA on Microsoft Windows. It is a binary data file intended for processing by the sequencing workflow rather than for viewing in a text editor.
CASAVA can process BCL data and export sequencing results in formats used by downstream analysis, such as FASTQ. This is normally performed as part of the CASAVA workflow rather than with a general-purpose file converter.
Because BCL files are instrument and workflow data, they should not be converted by editing or renaming the file extension.
File type category:
Various data file
Date updated: November 9, 2017
Record marked as obsolete and not updated for a long time.
The bcl file extension is associated with the PDP-10 mainframe computer developed by Digital Equipment Corporation.
The bcl file stores data sources for compiler. PDP-10 is obsolete type of computer released in 1968 and used in 1970's.
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