All about FASTA Files

The FASTA file type is primarily associated with DNA Baser Assembler.

FASTA	File extension: FASTA
	File type:	DNA and protein sequence file

What is a FASTA file?

FASTA files mostly belong to DNA Baser Assembler by Heracle BioSoft SRL. FA file extension is the standard scientific file format used in the fields of bioinformatics and biochemistry. It is more popularly known as the FASTA file format.

• Main Use: FA file format was initially introduced as a part of the FASTA software package and has since been accepted as the industry norm for representing nucleotide and protein sequences. The sequence data in the FA file is present in a plain-text format making it easily comprehensible for the user to read the file as well. Manipulation and parsing of the FASTA sequence can be done easily done using standard text-processors and script-based programming languages such as R, Python, Perl, and Ruby. FA file format is capable of storing multiple nucleotide/protein sequences and is hence also known as the FASTA database format. FA files can be analyzed using most DNA analysis software in the market.
• Features: FA files usually begin with a header line that includes comments or other descriptive information related to the sequence. The first line in a FA file usually starts with a > symbol followed by the name of the sequence. The subsequent line contains the nucleotide or peptide sequence made up of A, T, G, and C inline with the IUPAC code. Each line can consist of a maximum of 80 characters.

How can I open a FASTA file?

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

Online FASTA Text Viewer

Choose your .fasta file to view

or drag and drop it here

Online File Viewer

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

1. Just click the "Choose your .fasta file to view" button on this page.
2. Your FASTA file will then be displayed in the browser.
3. Now click on "Save as..." at the top of the page.
4. Then choose the file format (e.g. JPG, PDF, DOCX, TXT, ...) you want.
5. Download the converted file.

FASTA format details:

If you can determine the file format, the associated program can also be determined. The initial characters of a file are called signature, sometimes also referred to as "magic bytes". The signature can be used to infer the file format. Frequently, however, one file extension is used by different programs for different file formats, and one file format for different file extensions. When there is a problem with a file, the first step to solving it is to determine the file format. Our analysis of the FASTA files produces the following result:

The FASTA extension is very commonly used. This FASTA file itself is among the most popular common file types and includes very many different file formats. The two most popular formats are as follows:

• 15% of all FASTA files use the same file format, which have the signature 3E 4E. These files contain text and words, not binary data. Most of these files are 1 KB to 5 MB in size. The file type is very recent. Some examples of file names are sequence.fasta. Such files sometimes refer to sequences, covid, contigs, genome, refseq, data, protein and mouse.
• 6% of all FASTA files start with the bytes 3E 4D crucial for this file format. These files are plain text, which means they can be viewed with any text editor such as Windows Editor, Nano for Linux, and TextEdit for macOS. Most of these files are 550 bytes to 130 KB in size. A common filename is sequence.fasta or sample.fasta. Files like these are about reads, family, species and genus.

The remaining 79% of all FASTA files are different files with different signatures, the following 40 formats exist: ZIP and Chain. They are often associated with rcsb, uniprot, silva, group, galaxy, proteome or gene. You can get all the details of your FASTA file by dragging it onto this page or by clicking the button "Choose your .fasta file to view" above.