DNA → Protein Translation Tool

Paste a DNA coding strand and watch the central dogma happen step by step: transcription to mRNA, splitting into codons, and translation to protein — with the start and stop codons highlighted.

1. DNA coding strand (your input)
2. mRNA (transcription: every T → U)
3. Codons (read in threes; start / stop highlighted)
4. Protein (translation)
Length: 0 aa Start: — Stop: —

How to translate DNA to protein by hand

First transcribe: the mRNA has the same sequence as the DNA coding strand, except every thymine (T) becomes uracil (U). Then read the mRNA in non-overlapping groups of three bases called codons. Translation begins at the first start codon (AUG, which codes for methionine) and continues until a stop codon (UAA, UAG, or UGA), which codes for no amino acid and ends the protein. Each codon maps to one amino acid via the genetic code below. The reading frame matters — shifting the start by one base changes every codon downstream.

Note: this tool reads the coding (sense) strand in the 5′→3′ direction and uses the standard genetic code. It translates the full sequence in the chosen frame; in real cells, ribosomes begin at the first AUG.

The genetic code (mRNA codons)

Related tools: Peptide charge & pI calculator · Amino acid quiz · all biochem tools.