Codon Optimization Tool
Optimise a protein or CDS for expression in E. coli, human or yeast.
🔒 Runs entirely in your browser — nothing is uploaded
Codon-optimise a protein or coding DNA sequence for expression in E. coli, human or yeast using most-frequent-codon usage tables. A useful starting point when designing a synthetic gene or boosting recombinant protein expression — then refine with GC, repeat and secondary-structure checks before synthesis.
Optimised coding sequence
Result appears hereOptimisation picks the most frequent codon per residue for the chosen organism. Usage tables are reference approximations (Kazusa-derived); verify against your expression system for critical constructs.
How to use the Codon Optimizer tool
- 1Paste a protein sequence or a coding DNA sequence.
- 2Choose the target expression organism (E. coli, human or yeast).
- 3Copy the optimised coding sequence and review its GC content.
Frequently asked questions
- How does the optimisation work?
- For each amino acid, the most frequently used codon in the target organism is selected. Codon usage tables are reference approximations derived from the Kazusa database.
- Can I paste DNA instead of protein?
- Yes. If the input looks like a nucleotide sequence it is translated (frame +1, to the first stop) before optimisation.
- Should I rely on this for ordering a gene?
- Treat it as a starting point. Real optimisation also considers GC content windows, secondary structure, repeats and restriction sites — verify before synthesis.