Open-The-File.com

Find how to open any file type

How to open .ASN files on Windows

To open .ASN files on Windows, if the file came from NCBI Pathogen Detection, table2asn, or another NCBI biological workflow, install and open it with NCBI Genome Workbench.

Step-by-step instructions

  1. If the file came from NCBI Pathogen Detection, table2asn, or another NCBI biological workflow, install and open it with NCBI Genome Workbench.
  2. If it is a BLAST archive .asn file, use NCBI BLAST+ blast_formatter to convert it to a readable BLAST report format.
  3. If you only need to inspect the file, try a text editor; if the contents look unreadable, it is likely encoded and needs the appropriate NCBI tool.

Alternative methods

  • Open .ASN in a browser-based viewer if desktop apps fail.
  • Try opening .ASN on Windows with a secondary app to rule out app-specific issues.
  • Convert .ASN only with trusted tools when direct opening is not possible.

Common issues

The .asn file opens as unreadable text or symbols

Not every ASN.1 file is plain text. Some are encoded data intended for a specific parser or NCBI tool.

  1. Confirm the source of the file, such as BLAST, Pathogen Detection, or a GenBank submission workflow.
  2. Use the matching tool: Genome Workbench for supported NCBI biological ASN.1 files, or blast_formatter for BLAST archive output.
  3. Avoid manually editing encoded ASN.1 files in a text editor.

Genome Workbench does not open the file correctly

The file may not be the kind of NCBI ASN.1 data that Genome Workbench expects, or it may be incomplete or damaged.

  1. Re-download or re-export the file from the original NCBI tool or data source.
  2. Check whether the file is actually a BLAST archive, which should be handled with blast_formatter instead.
  3. Make sure you are using a current version of the relevant NCBI software.

The file is a BLAST .asn archive, not a normal report

BLAST archive output is saved as ASN.1 and is meant to be reformatted later rather than read directly.

  1. Install the NCBI BLAST+ command-line applications.
  2. Use blast_formatter with the .asn archive as input and select an output format such as a pairwise, tabular, XML, or other supported BLAST report format.
  3. Keep the original .asn archive if you may need to generate different report formats later.

The file does not work after renaming

Changing the extension to or from .asn does not convert the underlying data or encoding.

  1. Restore the original filename if you changed it.
  2. Use an export or conversion feature from the software that created the file.
  3. Ask the sender which program or NCBI workflow produced the file.

Security note

.asn files are normally data files, not macro-enabled documents, but they should still be opened only with trusted, up-to-date ASN.1-aware software because complex parsers can fail on malformed data.

Back to .ASN extension page