Sequence reverse complement
Reverse-complement DNA or RNA FASTA sequences using every IUPAC ambiguity symbol, with original case and headers retained.
Reverse-complements every FASTA record using the complete IUPAC DNA or RNA ambiguity alphabet. DNA uses A/T and RNA uses A/U. Case and optional - gaps are preserved; gaps reverse with the sequence. Original identifiers and full headers are retained. Header annotations and biological feature coordinates are not rewritten. This does not translate proteins or infer the biological strand. Runs locally without uploads or database lookup. Limit: 500000 combined input characters, 2000 records, 2000 validation issues, a 1000-symbol motif, 20000 matches and 10000000 symbol comparisons. Exceeding a limit rejects the complete report. Each export is limited to 3000000 characters; typed CSV allows 200000 values. Preview shows 200 rows. Processing stops after 10 seconds. Up to 500,000 characters. Review the settings before running.
Your result
How to use Sequence reverse complement
- Paste FASTA and choose DNA or RNA.
- Enable literal gaps only for aligned input.
- Review sequence lengths and download the reverse-complemented FASTA and report.
Useful next steps
Ambiguity codes are complemented
R and Y exchange, M and K exchange, B and V exchange, and D and H exchange. S, W and N remain themselves. DNA pairs A with T; RNA pairs A with U.
Annotations are not transformed
Headers retain their original text. Biological feature coordinates in those headers are not updated, and no biological strand is inferred.