How to open a JSON file online
Three steps, a few seconds, no software.
Open your .FASTA file
Drop it on the box, choose it from your device, or paste the data straight in.
View the structure
Your .FASTA file opens as a tidy, foldable tree, with the exact line of any error pointed out.
Search, copy or download
Search keys and values, copy any path or value, switch to a table, or download a clean copy.
What is a .FASTA file?
The most common data format on the web.
A FASTA file is a plain-text file that holds one or more biological sequences: DNA, RNA, or protein. Each record starts with a ">" header line followed by the sequence letters. You can open it in any text editor, but for analysis or alignment use free tools such as Jalview, AliView, UGENE, or MEGA.
Programs that open .FASTA files
| Full name | FASTA Sequence File (DNA / RNA / Protein) |
|---|---|
| Developer | William R. Pearson & David J. Lipman (FASTA program, 1985-1988) |
| First released | 1985 (FASTP/FASTA sequence-comparison program; format formalized 1988) |
| Category | Text & Code |
| MIME type | text/x-fasta |
| Signature | 3E ">" (greater-than) at the very start of each record header line |
Related viewers
Every viewer is free to use.
Frequently asked questions
Is my .FASTA file uploaded anywhere?
No. The file is opened directly from the copy you pick.
My .FASTA file is invalid. Can you fix it?
We show the exact line and column of the first error. For common problems like comments, trailing commas, single quotes or Python-style True/False/None, click Try to repair and download the fixed file.
How large can the file be?
Up to 50 MB. The tree only builds the branches you open, so even multi-megabyte files stay responsive.
What is JSONPath?
A path like $.orders[3].customer.email that points to one value inside the data. Click any node to see its path and copy it for code, jq or your API docs.
Can I see my data as a table?
Yes. Any array of objects can be shown in the Table view and downloaded as CSV.
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