FASTA to FASTQ Converter
Add a uniform quality score to every base so your FASTA file becomes valid FASTQ that any sequencing pipeline will accept.
Why convert FASTA to FASTQ?
Some pipelines and tools insist on FASTQ input even when quality data is irrelevant — for example when running a read mapper on reference sequences, or when testing a pipeline before real data is available. This converter adds a uniform quality score to every base so the file is valid FASTQ.
What quality score is used?
By default every base gets I, which is Phred score 40 in the standard Sanger
encoding — the highest quality a typical sequencer reports. Treat these as placeholder
values, not real measurements.
Frequently asked questions
Are my sequences modified?
No. Sequence letters are kept exactly as they appear; line wrapping is normalised and quality strings are generated to match each sequence length.
Can I convert many records at once?
Yes — paste a multi-record FASTA file and every record is converted, in order.