Reverse Complement Tool

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Paste or upload FASTA and raw DNA/RNA sequences to compute a reverse complement, complement, or reverse-only sequence with explicit bioinformatics alphabet and output-formatting controls.

Input
Accepts FASTA (>) or a raw sequence.
Plain-text FASTA recommended. Processed synchronously.
Operation
Alphabet
Output formatting
FASTA header options
Limits: up to 15 MB (uncompressed) • up to 400,000 records

About this tool

Compute reverse complements, complements, or reverse-only sequences for DNA or RNA. Accepts FASTA (multiple records) or a single raw sequence. Ambiguous IUPAC nucleotide codes are preserved and complemented (e.g. R↔Y, W↔W, N↔N). For background and worked examples of the reverse complement operation, see the reverse complement reference.

For larger datasets, multi-file runs, or more involved workflows, this can be executed separately as a custom analysis.

Tool guarantees
  • ✓ No hidden transformations or guessing
  • ✓ Input processed once and not stored
  • ✓ FASTA headers preserved

Results

Submit input to see results here.
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Useful for larger datasets, multiple files, or tasks that are not convenient to run locally.
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Examples

DNA and RNA reverse complement examples

DNA reverse complement

Input
GCTTACGA
Reverse complement
TCGTAAGC

RNA reverse complement

Input
GCUUACGA
Reverse complement
UCGUAAGC

IUPAC ambiguity symbols

Pairs
R↔Y · K↔M · S↔S · W↔W · N↔N
Use
Keep ambiguous nucleotide meaning while changing strand orientation.
Definition

What is a reverse complement?

The reverse complement of a DNA or RNA sequence is the sequence from the opposite strand, written in the standard 5′ to 3′ direction. Practically, each base is complemented and the sequence order is reversed.

For DNA, A pairs with T and C pairs with G. For RNA, A pairs with U and C pairs with G. Ambiguity symbols are complemented by mapping the possible base set to the opposite strand.

Related tools and references

Continue with related sequence checks

DNA ↔ RNA converterFASTA/FASTQ validatorSequence statsSequence alphabets referenceReverse complement reference
FAQ

Reverse complement tool FAQ

Does this support FASTA input?

Yes. You can paste or upload one or more FASTA records. FASTA headers are preserved in the output.

Can I use RNA sequences?

Yes. Choose RNA mode to use A↔U complement rules instead of DNA A↔T rules.

Are ambiguous bases supported?

Yes. IUPAC ambiguity codes such as R, Y, S, W, K, M, B, D, H, V, and N are handled explicitly.

Is uploaded or pasted sequence data stored?

Input is processed once for the request and not stored.