What is the reverse complement?

The reverse complement is obtained by first complementing each base (A→T, T→A, G→C, C→G for DNA) and then reversing the entire sequence. It represents the antiparallel strand of double-stranded DNA read in the 5'→3' direction.

What is the difference between complement and reverse complement?

The complement replaces each base with its Watson-Crick partner without changing the order. The reverse complement additionally reverses the sequence, giving the sequence of the opposite strand written 5'→3'.

How is RNA mode different?

In RNA mode, thymine (T) is replaced by uracil (U) and complementary rules become A↔U and G↔C. All T in the input are treated as U, and all output uses U instead of T.

What characters are accepted?

The tool accepts standard IUPAC bases: A, T (or U in RNA), G, C, plus ambiguity codes R, Y, S, W, K, M, B, D, H, V, N. Whitespace, digits, and line breaks are ignored. Unrecognized characters are shown as-is.

How is GC content calculated?

GC content = (count of G + count of C) / total unambiguous bases × 100. Only A, T/U, G, C are counted in the denominator; ambiguous codes are excluded.

DNA Reverse Complement Tool

Paste a DNA or RNA sequence to instantly get its complement, reverse, and reverse complement along with GC content and length.

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Paste a nucleotide sequence on the left to see results.

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Summary

The DNA Reverse Complement Tool instantly computes all four sequence representations — original, complement, reverse, and reverse complement — for any DNA or RNA sequence. It also reports GC content and sequence length, covering the core calculations needed for primer design, cloning, and sequence analysis.

How it works

Paste or type your nucleotide sequence into the input box (uppercase or lowercase, whitespace and digits are ignored).
Choose DNA or RNA mode using the toggle — DNA uses T, RNA uses U.
The tool instantly displays the original sequence, complement, reverse, and reverse complement.
GC content percentage and total sequence length are shown below the results.
Click any "Copy" button to copy that sequence to your clipboard.

Use cases

Design PCR primers by finding the reverse complement of the template strand.
Verify primer sequences before ordering from a synthesis provider.
Convert a DNA sense strand to its antisense complement.
Calculate GC content to estimate primer melting temperature.
Quickly flip an RNA sequence to its reverse complement for cloning work.
Check sequencing results against the expected reverse strand.

Frequently Asked Questions

Last updated: 2026-09-30 · Reviewed by Nham Vu