DNA ↔ RNA converter

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Convert DNA to RNA (T→U) or RNA to DNA (U→T). Supports FASTA or a raw sequence.

Input
Accepts FASTA (>) or a single raw sequence. FASTA headers are preserved.
Plain-text FASTA recommended. Processed synchronously.
Conversion
Output formatting
Optional checks
FASTA header options
Limits: up to 10 MB (uncompressed) • up to 400,000 records

About this tool

Converts nucleotide sequences by applying a single, explicit substitution: DNA→RNA replaces T with U, and RNA→DNA replaces U with T. FASTA headers are preserved (optionally with a suffix) and output formatting can be normalized (case / wrapping). Expected DNA and RNA letters are documented in the sequence alphabets reference.

Tool guarantees
  • ✓ No guessing: you choose the conversion direction
  • ✓ FASTA headers preserved (optional header suffix only)
  • ✓ Deterministic output
  • ✓ Input processed once and not stored

Results

Submit input to see results here.

  • DNA → RNA: replaces T/t with U/u in sequence characters.
  • RNA → DNA: replaces U/u with T/t in sequence characters.
  • FASTA handling: header lines (>) are preserved; sequence characters are converted.
  • Header suffix: when enabled, only the FASTA ID token (first token after >) is modified.
  • Line wrapping: applies to FASTA sequence lines only. Headers are never wrapped.
  • Validation: checks are warnings-only (no blocking). Mixed T/U and unexpected characters are reported.

  • Convert a DNA template into an RNA representation for quick checks.
  • Normalize sequences for tools that expect T-only or U-only alphabets.
  • Apply consistent case and FASTA line wrapping before sharing/downstream use.

DNA typically uses A/C/G/T, while RNA uses A/C/G/U. Converting between T and U is a common pre-processing step when moving between DNA- and RNA-oriented conventions.

This tool performs only the requested T↔U substitution, plus optional output formatting (case/wrapping) and warnings-only validation.