Opening ASN Files

The ASN file type is primarily associated with NCBI BLAST.

ASN	File extension: ASN
	File type:	text-based data file

What is an ASN file

ASN files mostly belong to NCBI BLAST.

BLAST Search Requests: Many ASN files come from NCBI BLAST. They hold text-based search queries, GenBank sequence data, and even position-specific scoring matrices. Use a text editor to view the content and a BLAST client to process it. For more details, visit NCBI BLAST.

ASN.1 Data Specifications: Other ASN files follow the Abstract Syntax Notation (ASN.1) standard. These files serve as data serialization formats and are used to define complex data structures such as digital certificates. More on this format is available at the ASN.1 project and RFC 2315.

Additional Uses: Some files using the ASN extension serve specialized roles like UI layout files for advanced streaming interfaces or data files for spectroscopic analysis. They still maintain a text-based structure and require specific software for proper interpretation.

Functionality: These files are structured text documents that follow strict formatting rules. They store data for search requests, bioinformatics analysis, certificate definitions, or even user interface layouts. While they can be opened with any plain text editor, proper processing usually involves specialized tools (e.g., NCBI BLAST or ASN.1 compilers).

How to open an ASN file

You need a suitable software like NCBI BLAST to open an ASN file. Without proper software you will receive a Windows message "How do you want to open this file?" or "Windows cannot open this file" or a similar Mac/iPhone/Android alert. If you cannot open your ASN file correctly, try to right-click or long-press the file. Then click "Open with" and choose an application. You can also display a ASN file directly in the browser:. Just drag the file onto this browser window and drop it.

Online ASN Text Viewer

Choose your .asn file to view

or drag and drop it here

Online File Viewer

✈

Read our privacy guarantee in Filext’s terms and privacy policy

Please allow ads on our site

This helps us keep our servers running. Then re-upload your file to view it.

Click here to see how to disable the ad blocker for filext.com

How to extract texts from ASN files or capture a screenshot to PDF, JPG, DOCX, TXT, ...

1. Just click the "Choose your .asn file to view" button on this page.
2. After your file is opened in browser,
3. click "Save as..." in the menu.
4. Then choose the file format (e.g. JPG, PDF, DOCX, TXT, ...) you want.
5. Download the converted file.

ASN file format:

Why is it important to know the file format? This is the only way to find out which program to use to open the file. The file format can be deduced from the file extension and the signature. Frequently, however, one file extension is used by different programs for different file formats, and one file format for different file extensions. So a detailed analysis of a file is vital in order to determine the format and the associated program. Our examination of the ASN files comes to the following conclusion:

The ASN file extension is quite common and includes different formats for different programs. The file formats most commonly found in ASN files are:

• 55% of all ASN files have the same signature Blast4-request. These files contain text and words, not binary data. The files are on average 8 KB in size and range from 2 KB to 8 KB. The file type is relatively new. The following keywords are characteristic: Blast4-request ::= {, body queue-search {, queries bioseq-set {, seq {, program "blastn", service "megablast", service "plain", Query, local str and local id 45965. A common filename is AP_Biology_Fossil_Gene1_search_strategy.asn. Such ASN files store data about strategy, search, gene, biology, fossil, blast and extracted.
• 7% of all ASN files save the data in certificate file format. A digital certificate is a unique, digitally signed document which authoritatively identifies the identity of an individual or organization. Using public key cryptography, its authenticity can be verified to ensure that the software or website you are using is legitimate. These files contain neither text nor words, but only data. A typical file size is 85 MB. Some examples of file names are Compound_000000001_000500000.asn.

All other ASN files (38%) have no uniform format, often, for example, Atlantis Word Processor Sound Scheme, DOC, Seq, Bio and PssmWithParameters. Sometimes used for scoremat, pssm, sdpoutputcdr, alignment, data, blastn or sgsn. Drag & drop your file here to see the file format and a preview of your ASN file!