Analyze DNA & RNA Sequences in Your Browser
A free comprehensive nucleotide sequence analyzer. Paste DNA or RNA to get the reverse complement, 6-frame protein translation, open reading frames with alternative start codons, restriction site map, primer quality analysis, and codon usage statistics. All computation happens in your browser.
How to analyze a DNA sequence
Paste DNA or RNA, drop a FASTA file into the textarea, or load it with the FASTA button. Sequences up to 1,000,000 nt are supported.
Switch tabs for reverse complement, translation, ORFs, restriction sites, primer check, and codon usage. Each tab updates instantly.
Copy any block to the clipboard, download the sequence as FASTA, or download the restriction map as CSV.
Translate in 6 frames, find ORFs, map restriction sites, and check primers
Show protein
Features
FAQ
What sequence formats are supported?
Plain DNA/RNA text, FASTA with > headers, and multi-line sequences. IUPAC ambiguity codes (R, Y, S, W, K, M, B, D, H, V, N) are recognized. Whitespace, numbers, and headers are stripped automatically.
Which restriction enzymes are included?
Over 650 type-II restriction enzymes with recognition sites and cut positions. By default the ~80 most commonly used are shown (EcoRI, BamHI, HindIII, NotI, XhoI, SalI, and friends); switch to "All enzymes" for the full REBASE-derived database with rare isoschizomers.
How is the primer Tm calculated?
Using the nearest-neighbor thermodynamic method with SantaLucia (1998) parameters. Conditions: 50 nM oligo, 50 mM Na+, 0 mM Mg2+. Accuracy is within ±1°C for typical 18–30 nt primers.
Why does the header Tm differ from the primer Tm?
The header uses Wallace (2°C·AT + 4°C·GC) for short (<14 nt) and a GC%-based formula for 14–50 nt; longer sequences omit Tm entirely. The Primer tab uses the more accurate nearest-neighbor method.
How are ORFs found?
All 6 frames (3 forward + 3 reverse complement) are scanned. An ORF spans from a start codon (ATG; mitochondrial also ATA/ATT/GTG; bacterial also GTG/TTG) to the next stop. Minimum length is configurable.
How does the analysis work?
Sequence analysis runs in your browser via JavaScript — the tool parses FASTA input, translates codons, and maps restriction sites in real time.
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