One-to-Three Amino Acid Converter

Convert one-letter amino acid codes to three-letter format. Upload a file or paste your amino acid sequences below.

Input (One-letter amino acid codes)

Text/FASTA

Click to upload or drag and drop

FASTA or text file

Max size: 50MB

Conversion options

Output formatting

Use uppercase output (ALA vs Ala)Add spaces between codesPreserve FASTA headers

Amino acid handling

Include unknown amino acids as UnkConvert modified amino acids

Output (Three-letter amino acid codes)

Text