AncestryDNA gives you ethnicity estimates and matches. Underneath those is the actual genotyping data — a file you own and can analyze yourself. Getting it takes a few clicks and one email confirmation. Reading it well takes a little context, which is what this guide is for.
What's in the AncestryDNA file
Like 23andMe, AncestryDNA runs a genotyping microarray, not whole-genome sequencing. It reads several hundred thousand pre-selected positions on the GRCh37 / build 37 reference. It does not sequence the rest of your genome.
The export is a tab-delimited text file named AncestryDNA.txt, delivered inside a zip. After the header preamble, each line carries five columns:
rsid— the marker identifierchromosomeposition— base-pair locationallele1allele2
The one structural difference from 23andMe worth remembering: Ancestry splits your two alleles into two separate columns (allele1, allele2) instead of combining them into a single AG-style genotype. If you ever feed the file into a tool, that distinction matters.
How to download it
- Sign in at Ancestry and click Settings (top right of your DNA results).
- Choose Download Raw DNA Data (sometimes shown under Download or delete DNA Data).
- Enter your account password, tick the consent box, and click Confirm.
- Open the email Ancestry sends and click Confirm data download. This email step is required — without it, the download won't unlock.
- Follow the link to download the zipped
AncestryDNA.txt.
Ancestry notes that once the file leaves their system it's no longer protected by their security — it's an ordinary file on your computer from that point on. Treat it accordingly.
Checking it against ClinVar
The genealogy features won't tell you whether any of your markers carry a clinical classification. For that, you compare your positions against ClinVar, the NIH's public archive that records how variants have been classified — benign, uncertain, likely pathogenic, or pathogenic — and how much review supports each call.
Doing that lookup by hand across ~700,000 markers isn't realistic. BioDecode handles it locally: point it at your AncestryDNA.txt, and it matches each position against a local copy of ClinVar on your own machine — nothing is uploaded. If that fits what you're trying to do, you can download BioDecode.
Don't over-read the result
Two limits apply to every consumer genotyping file, Ancestry's included.
First, a missing marker means nothing. The chip only tests the positions it was built to test. If a variant isn't in your file, the array simply didn't look there — it is not evidence you're in the clear.
Second, a flagged marker is a lead, not a diagnosis. Raw consumer data isn't clinically validated. A 2018 Genetics in Medicine study found roughly 40% of concerning variants in direct-to-consumer raw data were false positives against clinical-grade confirmation. Anything that looks important should be re-tested in an accredited (CLIA) lab and reviewed with a genetics professional before it informs any decision.
With those caveats in place, your AncestryDNA file is a fair starting point for private genome exploration. If you also have a 23andMe kit, the 23andMe guide covers its slightly different format, and how to find pathogenic variants explains the classification labels in depth.
Frequently asked questions
How long does the AncestryDNA download take?
Usually minutes, but it depends on the email confirmation step. You must click Confirm data download in the email Ancestry sends before the file becomes available.
Why does the AncestryDNA file have five columns instead of four?
Ancestry reports your two alleles in separate allele1 and allele2 columns. 23andMe combines them into one genotype column. The information is equivalent; the layout differs.
Is AncestryDNA whole-genome sequencing?
No. It is a genotyping array reading several hundred thousand selected positions on build 37, not a full sequence of your genome.
Can I analyze the file privately?
Yes. It is a local text file, so a desktop tool like BioDecode can match it against ClinVar entirely offline, with no upload.
Next step
See how BioDecode keeps genome analysis on your own machine.
Explore BioDecodeThis article is educational and is not medical advice.