Generate the reverse complement, complement, reversed sequence or cleaned DNA from plain-text, FASTA or GenBank input. IUPAC ambiguity codes are preserved and complemented where appropriate.
Reverse complement is the primary output. Open Other sequence outputs to inspect the complement, reversed sequence or cleaned input. Choose a sequence to download; the Output format setting determines plain text or FASTA.
Useful Checks
This is useful when sequence orientation must be fixed before primer design, restriction-site checks, or ORF translation.
Copy the cleaned sequence or reverse complement into downstream tools such as Primer Designer, Primer Binding Checker, Restriction Site Analyzer, ORF and Protein Translator, or Codon Optimizer.
Minimum Inputs Needed
DNA sequence.
Optional Settings
Line wrap
Controls how many bases are shown per line in the output.
Output format
Use Plain sequence for DNA text alone. FASTA labels the generated sequence; it does not preserve separate input records.
Upload sequence file (optional)
Use this instead of pasting if you already have a sequence file.
How To Use
Paste or upload the DNA sequence.
Choose wrapping and output format.
Click Generate.
Reverse complement is shown first. Open Other sequence outputs for Complement, Reverse sequence or Cleaned input, then copy the required output or select it for download. Clear removes the input and current results.
Understanding The Results
Reverse complement reverses the sequence and complements each base.
Complement changes each base but keeps the original order. For input written 5' to 3', this gives the paired strand read 3' to 5'; choose Reverse complement for that strand written 5' to 3'.
Reverse sequence reverses the order but does not complement bases.
Cleaned input shows the parsed sequence in uppercase.
Input statistics and results show length, exact bases, ambiguous bases and GC%. Ambiguous bases are excluded from the GC% denominator.
Accepted Input Formats
Raw DNA sequence.
FASTA. Headers are ignored. Multiple records are concatenated into one sequence rather than processed separately.
GenBank text with an ORIGIN sequence section. Feature annotations, including ori/origin-of-replication annotations, are ignored.
IUPAC ambiguity codes are supported.
Accepted uploads include .txt, .fa, .fasta, .fna, .ffn, .seq, .gb, .gbk, and .genbank. .dna / SnapGene binary files are not supported.
Assumptions And Limitations
This is a DNA tool. It does not treat RNA as a separate mode.
Record boundaries and annotations are not preserved in the output. Analyze unrelated FASTA records separately.
The browser tool accepts sequence files smaller than 2 MB and parsed sequences up to 100,000 bp.
Example
For input ATGCRY, Reverse complement gives RYGCAT, Complement gives TACGYR, and Reverse sequence gives YRCGTA.
Choose reverse complement when you need the opposite DNA strand written 5′ to 3′. Reversing text alone is a different operation. After changing strand or sequence origin, use coordinates relative to the sequence you pasted into the next tool. Enter a reverse primer in a checker as ordered, 5′ to 3′; do not reverse-complement it a second time.
Correcting highlighted input
When the main action rejects pasted sequence text, unsupported characters are highlighted in the field and the error message explains the problem. Correct the marked characters using the alphabet allowed by this tool, then run it again. The highlights update as you edit. A malformed FASTA or GenBank record may require a structural correction even when no individual character is marked.
Use note: These tools are for research and educational planning. Check important calculations and sequence designs before ordering reagents or running experiments.