FASTA QUAL to FASTQ

Combine FASTA sequences and QUAL quality scores into FASTQ format for NGS data analysis.

What is FASTA QUAL to FASTQ?

This tool combines FASTA sequences with their corresponding QUAL quality scores to create FASTQ format files. FASTQ is the standard format for storing nucleotide sequences with quality scores from high-throughput sequencing.

How to Use This Tool

  1. Paste or upload FASTA sequences in the left box
  2. Paste or upload matching QUAL scores in the right box
  3. FASTQ output appears automatically with Phred+33 encoding
  4. Download or copy the combined FASTQ file

When to Use

  • Converting older sequencing data (454, Sanger) to FASTQ
  • Preparing data for modern NGS analysis pipelines
  • Merging separated sequence and quality files
  • Converting between sequencing formats

FASTA Input Example

>Read1
ATCGATCGATCG
>Read2
GCTAGCTAGCTA

QUAL Input Example

>Read1
40 40 35 35 30 30 35 35 40 40 40 40
>Read2
35 35 35 30 30 30 30 30 35 35 35 35

FAQ

Q: What quality encoding is used?
A: Phred+33 (Sanger) encoding, the modern standard.

Q: What if I only have FASTA?
A: Leave QUAL empty for default quality scores (Q40).