Opening an FNA File

The FNA file type is primarily associated with NCBI BLAST.

FNA	File extension: FNA
	File type:	plain text file

What is an FNA file?

FNA files mostly belong to NCBI BLAST. FNA files are nucleotide sequence files in the FASTA format. They store genetic information as plain text, where each file typically starts with a header line that begins with a '>' symbol followed by the nucleotide sequence data.
This format is used to hold DNA sequences and, on occasion, RNA sequences. It is designed for simple storage and easy sharing of genetic data. Such files are integral in bioinformatics workflows, especially with tools like NCBI BLAST, which compare sequences for alignments and research purposes.
Key characteristics include:

The header line, often containing an identifier, begins with a '>'

Following lines contain nucleotide codes such as A, T, C, and G for DNA (or U for RNA)

Due to their plain text nature, FNA files can be opened with any standard text editor

FilExt.com tip: This makes them accessible while also allowing detailed sequence analysis using specialized software.

How to open an FNA file

You need a suitable software like NCBI BLAST to open an FNA 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 FNA file correctly, try to right-click or long-press the file. Then click "Open with" and choose an application. You can also display a FNA file directly in the browser:. Just drag the file onto this browser window and drop it.

Online FNA Text Viewer

Choose your .fna file to view

or drag and drop it here

Online File Viewer

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

If you want to extract texts from FNA file or capture a screenshot, you can use our free Online FNA File Viewer:

Just click the "Choose your .fna file to view" button on this page.
After your file is opened in browser,
click "Save as..." in the menu.
Then choose the file format (e.g. JPG, PDF, DOCX, TXT, ...) you want.
Your file will be converted and downloaded.

Programs that open and convert FNA files:

NCBI BLAST
See the previous paragraphs to learn more about the main application. FNA files are often referred to as NCBI BLAST simple text files because this type of file is primarily created or used by this software.
FASTA Format
FASTA is a DNA and Protein sequence alignment software package first described (as FASTP) by David J. Lipman and William R. Pearson in 1985 in the article Rapid and sensitive protein similarity searches. The original FASTP program was designed for protein sequence similarity searching. FASTA format files often have file extensions like .fa, .mpfa, .fna, .fsa, .fas or .fasta. The identifying characters used for this association are - Hex: 3E, ASCII: >. Related links: Wikipedia FASTA Page, Wikipedia FASTA Format Page

FNA file format:

If you can determine the file format, the associated program can also be determined. The first characters in a file identify the file format, for example, HTML files start with the bytes <html>. 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 analysis of the FNA files produces the following result:

FNA is one of the most common file extensions and includes various formats for various programs. But the following two file formats are common:

40% of all FNA files use the same file format, which have the signature 3E 4E. These files are text files, so they contain words and text. The files are 3 KB to 3 GB in size, with a median of 4 MB. This file type is new and state-of-the-art. The keywords chromosome, genome, Homo and sapiens are typical for these files. A common filename is gene.fna or GRCh38_latest_genomic.fna. These files can be linked to genomic, grch, latest, viral, proj, scaf, bacteria and genome.
8% of all FNA files start with the bytes 3E 43, which are crucial for this file format. These files are text files, so they contain words and text. FNA files can be up to 5 GB in size, but are often around 45 KB - 1 GB. The keywords chromosome, contig, genome, length and numreads are typical for these files. These files are attributed to contigs, chcs, chcsebi, mutant and seqs.

All other FNA files (52%) have different formats, the following 18 formats can be found: lcl. Files like these are sometimes linked to aryc, phage, sequences, assembly, trimmed or laec. If you want to find out which format your FNA file belongs to, just click on the button "Choose your .fna file to view".

Technical Data for FNA File Extension

File classification:

Simple text file

Identifier:

Hex: 3E, ASCII: > (provided by TrID database)

Related files:

fa, fasta, ffn, faa, frn, gz, zip, tar, jsonl, fa, fastq, gbff, tsv, txt, gff, fq, dll, fsa, pdb, json, gff3, rar, mpfa

Mime type:

text/x-fasta

an fna plain text file is a special file format and should only be edited and saved with the appropriate software.

How to solve problems with FNA files

Associate the FNA file extension with the correct application.
Update your software that should actually open plain text files. Because only the current version supports the latest FNA file format. Search, therefore, e.g. on the manufacturer website after an available NCBI BLAST update.
To make sure that your FNA file is not corrupted or virus-infected, get the file again and scan it with Google's virustotal.com.
Click here to open your .FNA file online - secure, fast, and no downloads needed.