Sequence Format Converter — FASTA ⇄ GenBank ⇄ TSV
Convert between FASTA, GenBank and tab-separated formats, and extract CDS or protein sequences.
Convert a sequence from one file format to another in seconds. Paste FASTA or a GenBank flat file — the input format is auto-detected — then pick an output: FASTA sequence, FASTA of the CDS features (as nucleotides or translated protein), a minimal GenBank record, or a tab-separated name/length/sequence table. It is a focused way to reformat records copied from NCBI, a paper, or a plasmid editor before feeding them into another tool.
Convert many files at once — a folder works too
Each file keeps its own name, with the target format's extension. Up to 200 at a time.
How to use the Format Converter tool
- 1Paste a FASTA or GenBank record, drop a file onto the box (a SnapGene .dna, GenBank, FASTA or Sanger .ab1), or load the example; the input format is auto-detected.
- 2Choose the output format — FASTA, FASTA of CDS features (nucleotide or protein), minimal GenBank, or tab-separated.
- 3Copy the converted output or download it as a file.
Frequently asked questions
Which formats can it convert between?
It reads FASTA and GenBank flat files and writes FASTA (whole sequence), FASTA of each CDS feature as nucleotides or translated protein, a minimal valid GenBank record, or a tab-separated name/length/sequence table. A SnapGene .dna dropped on the box is read as the GenBank record inside it, features included, which is how to hand a .dna to NEBuilder or pLannotate — neither accepts one — and a Sanger .ab1 or .scf trace is read as its base calls.
How does it extract CDS or protein sequences?
For GenBank input it reads the FEATURES table, slices each CDS by its location (handling complement(...) and join(...) spans), and either outputs the nucleotide sequence or translates it with the standard genetic code. CDS/protein extraction needs GenBank input, since plain FASTA carries no feature annotations.
Can I run this from code?
Yes — the same conversion is available via the REST API and the MCP server.
More
Guides
Related tools
Apply one operation — or a chain of them — to every record in a multi-FASTA and export a single CSV/TSV table.
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Paste a sequence and find out what it is, against the whole of GenBank, with the program chosen for you.