How to Convert MyHeritage Raw Data to 23andMe Format for Free
Convert MyHeritage raw data to 23andMe format for free in your browser. Genotypes are copied into the exact 23andMe layout, never uploaded or altered.
You can convert a MyHeritage raw DNA CSV to 23andMe format for free. The converter reads the MyHeritage file in your browser, writes the same genotypes in the exact four-column 23andMe layout, and gives you a .txt download. Your file is never uploaded and no account is needed.
How do I convert MyHeritage raw data to 23andMe format for free?
Drop the MyHeritage download on the converter page. You can drop the .zip as it came, or the .csv inside it. Choose 23andMe as the output layout and download the converted .txt. A typical MyHeritage file has hundreds of thousands of rows. The whole thing happens in the browser, so the file does not leave your device.
If you want to know what is happening under the surface, MyHeritage raw data is a comma-separated table with one row per marker. The converter reads the RSID, chromosome, position and result columns, then writes those same rows in 23andMe's tab-separated layout, with a no-call marker and a first line stating the file was converted, so no tool mistakes it for a real 23andMe export.
What actually changes when the file is converted
The table below shows the real changes. The genotypes are not one of them.
| MyHeritage input | 23andMe output | |
|---|---|---|
| Separator | comma | tab |
| Column order | RSID, chromosome, position, result | rsid, chromosome, position, genotype |
| No-call marker | -- | -- |
| Genotype letters | copied exactly | copied exactly |
| First line | MyHeritage header | Comment stating the file was converted |
Scroll the table sideways for the rest →
The converter changes layout, not genotypes.
The important row is the no-call marker: it stays -- in both formats. A position the chip did not read stays unread. The converter never guesses a missing call and never flips a letter between strands.
The thing people get wrong about this conversion
People assume converting to 23andMe format makes the file a 23andMe file. It does not. It makes a MyHeritage file with 23andMe's layout. The DNA is still MyHeritage's chip, with MyHeritage's tested positions and MyHeritage's no-calls. If a third-party tool expects a 23andMe-style text file, this solves that problem. It does not make the file acceptable to 23andMe itself, and it cannot add markers MyHeritage never tested.
The converted file is not a 23andMe export
Do not upload a converted MyHeritage file to 23andMe. The first line says the file was converted, so the file is not mistaken for a real 23andMe export. A converted file is for third-party tools, browsers, analyzers and reports that ask for '23andMe raw data' but will accept a file in that format. If you need a 23andMe account feature, you need 23andMe's own test.
Why the browser-local part matters
The converter runs entirely in your browser. Your raw DNA file is never uploaded to a server. This matters because a raw DNA file is a large table of your genotypes. The page downloads only its own code and, for coordinate conversion, a public mapping file if you ask for a build lift. Nothing from your DNA is sent back. That is the reason the tool can be free and private, not a side detail.
What the converter will not do
- It will not change a genotype.
- It will not fill a no-call.
- It will not add positions MyHeritage did not test.
- It will not convert GRCh38 to GRCh37 unless you specifically choose that. MyHeritage files are already on the build 23andMe uses.
- It will not turn a damaged, partial or re-saved spreadsheet file into a valid result. If the MyHeritage CSV was edited in Excel, the columns or quoting may have changed, and the converter can only read what is actually there.
The limitations are the point. A raw DNA conversion should be a copy in a different layout, not a reinterpretation.
The converter copies genotypes. It does not call, impute, or change them.
Open the free converter at healthosx.com/dna/convert/myheritage-to-23andme and run it on your own file. If you want those genotypes interpreted, the free report on the same site reads the converted file like any other.
New to raw DNA files? Start with the full guide: How to Download & Analyze Your 23andMe Raw Data Free
Written by
HealthOS Research