About the data

Where the data comes from: the public FamilyTreeDNA trees, Y-DNA Haplotree and mtDNA Haplotree, and the FTDNA Discover service, which gives branch ages. Copies of the trees are downloaded weekly; after a check, the site is rebuilt from scratch.

A kit's country is the homeland of the earliest known ancestor on that line, and the FTDNA customer enters it themselves. It is not a place of residence and not a random sample of the population. The US, Britain and Scandinavia are over-represented, Africa and Asia are nearly empty, and some countries are skewed by diaspora. For example, on the maternal line Spain is roughly 18% Native American because Latin Americans report their colonial ancestors' country; Belarus and Lithuania are 15–20% Ashkenazi.

Kits with no country, or marked Unknown Origin, are not counted: 61% of all Y-DNA kits and 74% of mtDNA kits. They contain more African lineages than kits with a country, so the world share of haplogroup L on this site is understated.

One country is deliberately relabelled: “Italy (Aosta Valley)” is shown as Orstkhoy, a people closely related to the Chechens and Ingush who report this region because of a similar flag. Details on its page.

Regions are counted separately from their country: “Russia (Republic of Dagestan)” is not part of “Russian Federation”, “Spain (Catalonia)” is not part of “Spain”. A region's page links to its country.

A short name with no refinement (J-M172, H, I2) means the test did not reach the fine branches: on Y-DNA an STR test or an old SNP pack, on mtDNA an HVR test without a full read. In the major-branch list such kits are gathered under an asterisk: they sit on the branch but fall into none of its major sub-branches.

A branch and its sub-branch never stand in one list as equals. Either it is a tree, where a branch includes all its sub-branches, or a list where every kit is counted once and the remainder on the branch itself is marked with an asterisk.

Branch age is how many years ago the common ancestor of all its testers lived (TMRCA), as estimated by FTDNA Discover. The midpoint of the estimate is taken, rounded to a hundred years; above 10,000 years it is rounded up to a whole thousand. mt branch ages come from FTDNA's Mitotree where the branch exists there.

One set of thresholds for the whole site: countries under 50 kits are flagged as small and left out of the findings; similar countries are computed from 100 kits; a distinctive branch needs at least 10 kits.

YFull data #

The second source is the public YFull trees (Y and mt), copy of 2026-09-29, refreshed monthly. YFull is a paid analysis of the full Y chromosome and the full mtDNA, so its customers are even more of enthusiasts and project members than FTDNA's. Saudi Arabia, for example, contributes more samples there than any other country.

Comparisons with FTDNA use only YFull customers (samples with a YF number) and only living people. Ancient DNA and samples from scientific papers and the GenBank database are excluded, because FTDNA counts customers only. For mtDNA fewer than a third of YFull samples qualify, so maternal-line comparisons are thinner.

The YFull and FTDNA trees branch differently and name branches after different mutations. To compare them, every YFull sample is placed on the FTDNA tree by mutations the two trees share: 88% of YFull branches find their FTDNA branch directly, the rest through the nearest branch above for which a match was found. Shares are then computed the same way as for FTDNA kits.

Country and region on YFull, as on FTDNA, are given by the tested person. YFull regions are linked to FTDNA pages by hand: republics of Russia, Spanish autonomies (through provinces), regions of Italy, parts of the United Kingdom. Samples from a region that has its own FTDNA page are taken out of the country.

Language on YFull is what the tested person named as their native language (ISO 639-3 code); FTDNA has no such field. Language is not the same as people or region: Chechens of Jordan are counted with Chechens of Chechnya, and “Arabic” spans every Arab country.

The ypredictor tool #

Sister project ypredictor.github.io: paste your FTDNA STR markers to get a predicted Y-tree branch and your closest matches. Match countries there link back to pages of this site.