FASTQ Quality Viewer

Open FASTQ files directly in the browser to visualize per-base Phred quality scores, GC distribution, and sequence length distribution.

Drop a .fastq file or click to browse

All processing happens in your browser — no data is uploaded

QUALITY SCORE REFERENCE

  • Q30: 1 in 1,000 error rate (99.9% accuracy)
  • Q20: 1 in 100 error rate (99% accuracy)
  • Q10: 1 in 10 error rate (90% accuracy)
  • • Illumina typically produces >80% bases ≥ Q30