HelisomaFree tool

Raw DNA file checker

Drop your file and see in seconds what it is: which test or lab it came from, how many markers it holds, how many of the report’s markers are in it, and whether it reads cleanly. The file is read in your browser and never uploaded.

File type and reference build
Markers read, and how many of the report’s 647 are in it
Whether sex can be read from the file
What is wrong, if it can’t be read

No account, no card. The file is read on your device and never uploaded.

Upload DNA file →

ResultYour file

01The check

What the raw DNA file check looks at

Five things, read straight from your file in your browser.

Check	What it tells you
File type	Which test made the file: 23andMe, AncestryDNA, MyHeritage, FamilyTreeDNA, or a VCF from a lab. For a VCF, also whether it is a whole genome and which reference build it uses (GRCh37 or GRCh38).
Markers read	How many genotype calls were read cleanly. A chip file holds about 600,000 to 700,000; a whole genome VCF holds millions. A much smaller number usually means a cut-off download.
Report markers in the file	How many of the 647 markers the Helisoma report reads are in your file. Most 23andMe and AncestryDNA files carry most of them; FamilyTreeDNA and gene panels carry fewer, which means fewer findings, not wrong ones.
Biological sex	Whether the X and Y calls in the file are enough to tell. Many sequencing VCFs leave them out; then you pick it in one tap.
Problems	If the file can’t be read, the check says what it found instead (a PDF report, raw reads, a re-saved spreadsheet, an empty or damaged download) and how to get the right file.

02Fixes

Why a raw DNA file fails, and how to fix it

Most problems come from the download, not the DNA. Steps for every test are in the download guide.

A PDF or a screenshot

That is a report, not raw data. Request the raw data download from your test’s account settings; it arrives as a .zip, .txt, .csv or .vcf.

A .zip that won’t read

Usually a download that stopped early. Download it again and drop the .zip as it is, without unpacking it.

A spreadsheet opened in Excel

Saving a raw file in Excel or Numbers changes it. Use the original file from your test, untouched.

FASTQ, BAM or CRAM

Raw sequencing reads, not genotype calls. Download the VCF from your lab instead; every sequencing provider offers one.

Few report markers

Gene panels, exomes and some older chips cover fewer of the studied markers. The file still works; the report is shorter.

03Questions

Raw DNA file questions

How do I check if my raw DNA file is valid?

Drop it in the box on this page. Your browser reads it and shows the file type, how many markers it holds, how many report markers are in it and whether anything is wrong, in seconds and with no account.

Is my raw DNA file uploaded when I check it?

No. The file is read in your browser on your own device. To build the free analysis, only the few hundred markers the report needs are sent, well under a megabyte, and they are deleted within an hour unless you create an account.

Which files can be checked?

Raw data from 23andMe, AncestryDNA, MyHeritage, FamilyTreeDNA and Genotek, and VCF files from Nebula Genomics, Dante Labs, Sequencing.com or any lab, including whole genome VCFs of several gigabytes. Zipped and gzipped files work as downloaded.

How many markers should a raw DNA file have?

A consumer chip file usually holds about 600,000 to 700,000 markers, and a whole genome VCF holds millions of rows. A file with far fewer is usually a cut-off download or a gene panel.

Why does my file say “no-calls” or “--”?

Every chip file has thousands of positions the chip could not read confidently. They are written as -- or 00 and are skipped. They never mean a negative result.

What happens after the check?

The free analysis appears below the check: your first findings on food, training, sleep and mood, each with its study. The full report is a one-time $49, no subscription.

04From the blog

More on raw DNA files

Science

How accurate is your raw DNA data, honestly?

Consumer DNA chips are excellent at common variants and unreliable at rare ones: a clinical lab found 40% of rare raw-data findings were false positives. Here is where the line runs and how to stay on the right side of it.

Jul 9, 2026 · 3 min read

Guide

What can you do with your raw DNA data? 9 ideas worth your time

Your raw DNA file holds far more than the ancestry report used. Nine things to do with it, from coffee and sleep to blood tests and your own AI.

Aug 3, 2026 · 8 min read