Sequence line wrapper

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Wrap sequence lines in FASTA or plain text to a fixed width while preserving headers. Useful for formatting and preparing sequences for downstream tools.

Input
Accepts FASTA or plain sequence text.
Plain-text FASTA or sequence text. Processed synchronously.
Number of sequence characters per line.
Limits: up to 15 MB (uncompressed) • up to 500,000 records

About this tool

Sequence Line Wrapper reformats FASTA or plain sequence input by wrapping sequence lines to a fixed width while preserving headers exactly. This is useful for standardizing FASTA formatting before sharing, submission, or downstream tools that expect fixed-width sequences. For filtering or modifying sequences, see FASTA length filter. For FASTA structure and formatting rules, see FASTA format reference.

Tool guarantees
  • ✓ No hidden transformations
  • ✓ Input processed only for this request
  • ✓ FASTA structure preserved in output

Results

Submit input to see results here.