How to Convert FamilyTreeDNA Raw Data to 23andMe Format for Free

How do I convert FamilyTreeDNA raw data to 23andMe format for free?

Drop a FamilyTreeDNA Family Finder file on the free raw DNA converter, choose 23andMe as the output, and download the converted file. The converter reads the FTDNA columns and writes the same genotypes in 23andMe's exact four-column layout. The file is read in your browser, never uploaded, and no account is needed.

Here is the short version:

• Download your FTDNA Family Finder raw data file. It is usually a .txt, .csv, or a .zip that contains one of those.
• Open the FTDNA to 23andMe converter.
• Drop the file as it came from FTDNA. Do not open it in Excel first.
• Choose 23andMe as the output format.
• Download the converted file.

What the Converter Actually Reads and Writes

FamilyTreeDNA Family Finder raw data is a row-per-marker file. Each row gives an rsID, a chromosome, a position, and a result. 23andMe raw data is a four-column text file: rsid, chromosome, position, and genotype. The converter maps the FTDNA columns onto the 23andMe columns.

The output uses 23andMe's column order, chromosome names, separators, quoting, and no-call marker. The first line says the file was converted, not that it came from 23andMe.

Genotypes Are Copied, Not Changed

The converter renames columns and rearranges lines. It does not reinterpret genotypes, and it does not guess missing calls.

For every row it can read, the converter takes the two letters from the FTDNA result and writes them in the genotype column of the 23andMe layout. No-call markers are written as 23andMe's no-call marker. A heterozygous AG stays AG. A homozygous GG stays GG. There is no imputation and no phasing.

This matters because a converted file should describe the same tested positions. If your FTDNA file has a missing call, a tool that accepts the converted file sees a missing call in 23andMe's format, not an invented genotype.

Why the File Never Leaves Your Browser

The converter works in your browser. When you drop the file on the page, your browser reads it locally and writes the converted file to your device. The page counts that a conversion ran and its outcome, not the file, its name, or any genotype.

That is the same privacy model as the free DNA file checker and the free report. You can convert a DNA file on a shared computer without sending genetic data anywhere.

What About FTDNA's Missing Y and mtDNA Positions?

FamilyTreeDNA's Family Finder file is an autosomal test. It covers chromosomes 1 through 22 and X, not Y or mitochondrial DNA. The converter writes what is in the file. It cannot add Y-DNA or mtDNA markers that FTDNA did not test.

If a later tool asks for a haplogroup, a converted Family Finder file may still say there are no usable positions. That is not a failure of the conversion. It is a limit of the original test.

Why a Converted File Might Still Get Rejected

A common reason a converted file fails is not the conversion itself. It is that the file was opened in Excel or another spreadsheet and re-saved. Spreadsheets can change separators, alter a header, or quietly reformat values. If a tool rejects your file, re-download the original FTDNA file and convert that raw copy directly.

A second point people miss. The converted file is for tools that accept 23andMe raw data format. It is not an official 23andMe export, and 23andMe itself does not accept raw data uploads from other companies. Use it for third-party tools, apps, or analyses that ask for 23andMe layout.

Open the FTDNA to 23andMe converter at https://healthosx.com/dna/convert/ftdna-to-23andme and convert your file now. It reads your FTDNA Family Finder file in the browser and writes the same genotypes in the 23andMe layout, no account and no upload.