Reverse Complement (DNA/RNA)
Instantly generate reverse complements for nucleotide sequences. Supports IUPAC ambiguity codes, preserves FASTA headers, and runs 100% client-side for total privacy.
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About the Reverse Complement Tool
The reverse complement of a nucleotide sequence involves two steps: first, reversing the order of bases (5'→3' becomes 3'→5'), and second, swapping each base with its Watson-Crick pair (A↔T, C↔G). This operation is fundamental in bioinformatics for visualizing the opposite strand of DNA or preparing primers.
Full IUPAC Support
Unlike basic tools that only handle A, C, G, and T, this tool supports
the full standard IUPAC ambiguity codes. Ambiguous bases like R (Purine: A or G) are correctly complemented to Y (Pyrimidine:
T or C), ensuring validity for consensus sequences and degenerate primers.
Key Features
- Privacy First: All processing is local. Your sensitive genomic data never leaves your browser.
- Multi-FASTA: Paste multiple sequences with headers; they are processed individually.
- Large Files: Supports large inputs (up to 20MB) with drag-and-drop functionality.
- RNA Support: Automatically handles Uracil (U) by pairing it with Adenine (A).
Use Cases
- • Designing reverse PCR primers.
- • Visualizing the template strand from a coding strand.
- • Processing consensus sequences with ambiguous bases.
Related Tools
Frequently Asked Questions
Is there a file size limit?
Yes. To keep your browser responsive, we limit files to 20MB. For
larger genomes, command-line tools like seqtk are recommended.
Does it handle RNA?
Yes. The tool treats 'U' as Uracil and complements it to 'A'. It also preserves the case of your input (lowercase stays lowercase).
Can I paste raw sequences?
Absolutely. If no FASTA headers (>) are detected,
the input is treated as a single raw sequence.
Is my data secure?
Yes. This is a static site. No data is ever sent to a server; everything is calculated in your browser's JavaScript engine.