DNA Sequence Analyzer
Paste any DNA sequence for instant bioinformatics analysis — GC content, ORF finder, protein translation, restriction enzymes, primer design, and mutation detection.
Paste a DNA sequence above and click Analyze to see statistics.
Run the ORF finder above.
Configure options above and click Translate.
Paste two sequences above to compare them.
Run the restriction enzyme finder above.
Configure primer parameters and click Design Primers.
How to Use the DNA Sequence Analyzer
Paste any raw DNA sequence (A, T, G, C characters — spaces, numbers and newlines are automatically stripped) into the input box and click Analyze Sequence. All six analysis tools will receive your sequence. Switch between tabs to explore different analyses.
What sequences can I analyze?
Any DNA sequence in IUPAC format. The tool automatically removes whitespace, numbers, and FASTA header lines (lines starting with >). Sequences from GenBank, Ensembl, NCBI, or your own lab data all work.
GC Content Calculator
GC content is the percentage of guanine and cytosine bases in a DNA sequence. It affects melting temperature, genome stability, and codon usage bias. Our calculator shows exact nucleotide counts, GC%, AT%, and a visual composition bar.
- GC content above 50% → more thermally stable DNA
- Human genome average: ~41% GC content
- Bacterial genomes range from ~25% (Mycoplasma) to ~72% (Streptomyces)
Open Reading Frame (ORF) Finder
An open reading frame is a sequence of DNA that begins with a start codon (ATG) and ends with a stop codon (TAA, TAG, or TGA) without any intervening stop codons. ORFs are the primary candidates for protein-coding genes.
6-Frame Translation
DNA can be read in six frames: three on the forward strand (+1, +2, +3) and three on the reverse complement strand (−1, −2, −3). This tool scans all six frames and reports every ORF above your minimum length threshold.
DNA to Protein Translation
DNA is transcribed to mRNA and then translated to protein via the genetic code. Each three-nucleotide codon encodes one of 20 amino acids. This translator uses the standard genetic code (NCBI translation table 1).
Restriction Enzyme Sites
Restriction enzymes cut DNA at specific recognition sequences. Our finder scans for 30+ common enzymes used in molecular cloning including:
- EcoRI — GAATTC (most common cloning enzyme)
- BamHI — GGATCC (compatible with BclI ends)
- HindIII — AAGCTT (useful for lambda phage cloning)
- NotI — GCGGCCGC (8-cutter, rare cutter)
See Free DNA Sequence Analyzer in action
Free DNA Sequence Analyzer
Paste any raw DNA sequence — from GenBank, Ensembl, NCBI, a FASTA file, or your own lab data — and run six bioinformatics analyses in one place: sequence statistics, an open reading frame (ORF) finder, protein translation, mutation detection between two sequences, restriction enzyme site scanning, and primer design.
The tool automatically strips whitespace, numbers and FASTA header lines from your input, so you can paste a sequence straight from a database export without cleaning it up first, then switch between analysis tabs to explore each result.
Key features
Sequence statistics
Length, GC/AT content, nucleotide counts, molecular weight and reverse complement in one click.
ORF finder (6-frame)
Scans all six reading frames for ATG-to-stop-codon open reading frames with protein length estimates.
Protein translator
Translates DNA to amino acids using the standard genetic code, codon by codon.
Restriction enzyme & primer tools
Finds cut sites for 30+ common enzymes and designs primers with Tm, GC% and GC-clamp analysis.
How to use it
- Paste a raw DNA sequence — spaces, numbers and FASTA headers are stripped automatically.
- Click Analyze Sequence to run all six analysis tools on it.
- Switch between tabs (Stats, ORF, Protein, Mutation, Enzymes, Primers) to explore each result.
- Use the mutation tab to compare two sequences side by side, if needed.
Worked example
Example
Paste a short coding sequence starting with ATG. The Stats tab shows GC content and length; the ORF tab finds the open reading frame across all 6 frames; the Protein tab translates it codon-by-codon into the corresponding amino acid chain.
Who uses this tool
Biology & bioinformatics students
Explore GC content, ORFs and translation hands-on while learning molecular biology concepts.
Researchers
Quickly check restriction sites or design primers for a sequence without opening dedicated lab software.
Lab technicians
Verify sequence statistics or scan for restriction enzyme cut sites before planning a cloning step.
Tips for the best results
- The tool accepts sequences with FASTA header lines (starting with >) — they're stripped automatically, no need to remove them manually.
- Use the ORF finder's 6-frame scan when you're not sure which strand or frame the coding sequence is on.
- Check GC content before assuming melting temperature or stability — GC content above 50% generally means more thermally stable DNA.
- For primer design, review both the Tm and GC clamp together, not just one in isolation.
Common mistakes to avoid
- Pasting protein sequences (amino acid letters) instead of DNA — this tool expects A, T, G, C nucleotide characters.
- Assuming the first ORF found is automatically the "real" gene — biological context and known start codons still matter.
- Ignoring reverse-strand reading frames when the coding sequence could be on the reverse complement.
Why use AZRS QuickFix?
It is 100% free, needs no signup and has no watermark or usage limits. The tool runs in your browser, so what you type stays on your device, and it works on phones, tablets and desktops. New tools are added every week — bookmark this page or browse the full QuickFix toolbox.
Frequently asked questions
Is this DNA analyzer free?
Yes, completely free with no signup required.
What sequences can I analyze?
Any DNA sequence in IUPAC format — the tool strips whitespace, numbers and FASTA headers automatically, so exports from GenBank, Ensembl or NCBI work directly.
What is an open reading frame (ORF)?
A DNA sequence starting with a start codon (ATG) and ending with a stop codon, without any intervening stop codons — a primary candidate for a protein-coding gene.
How many restriction enzymes does it check?
30+ common enzymes used in molecular cloning, including EcoRI, BamHI, HindIII and NotI.
Can it compare two sequences for mutations?
Yes, the Mutation tab compares two sequences and flags substitutions, insertions and deletions with position annotations.
Does it translate DNA to protein?
Yes, using the standard genetic code (NCBI translation table 1), shown codon by codon.