A little curiosity. A lot of discovery.
Your DNA.
A whole world of
discovery.
Meet your matches. Untangle your family tree. Discover the little things that make you, you — with free tools that keep your DNA on your device.
- Private by design
- Free to explore. No sign-up.
- Real science, clearly explained
Big connections.
CHOOSE YOUR ADVENTURE
Small tools. Big “aha!” moments.
Pick a starting point and follow your curiosity. Every tool is free, private, and ready when you are.
Shared cM Calculator
Turn a shared centimorgan number into a ranked list of possible relationships.
Let’s figure it out DISCOVERY TOOLRelationship Calculator
Name the relationship between two people from their positions in a family tree.
Let’s figure it out DISCOVERY TOOLCousin Calculator
Work out cousin degree and how many times removed, with the path shown.
Let’s figure it out DISCOVERY TOOLDNA Percentage Calculator
Convert between percentages, centimorgans and relationships.
Let’s figure it out DISCOVERY TOOLInheritance Calculator
Project how much DNA you expect to carry from a specific ancestor.
Let’s figure it out DISCOVERY TOOLExpected cM Range
Look up the expected centimorgan range for any relationship.
Let’s figure it out
How it works
The server never sees your DNA, because there is nothing to send it to
DNADojo is a static site. The pages come from a CDN, the calculations happen in JavaScript on your machine, and raw genotype files are parsed in a Web Worker that has no network access of its own. Privacy here is not a policy promise layered over a database — it is the absence of a database.
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Type a number, or pick a file
Calculators take a cM value. The Explorer takes a raw genotype file straight from your disk.
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Everything computes locally
Relationship maths is a few kilobytes of TypeScript. File parsing streams through a Web Worker so the page never freezes.
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Close the tab, it is gone
Nothing is persisted unless you explicitly ask to keep a project on this device — and one button clears it.
Why it matters
Genetic data is the one file you cannot re-issue
You can change a password. You cannot change your genome, and neither can your relatives, who never consented to your test. That asymmetry is the whole reason this site is built the way it is.
No raw DNA on our servers
Not encrypted-at-rest, not "temporarily" — the architecture has no upload path at all.
No cross-user matching database
DNADojo does not build a pool of strangers' DNA to search, so there is nothing to subpoena or sell.
No health interpretation
Genealogy and education only. No disease risk, no carrier status, no medication guidance.
THE KNOWLEDGE CLUB
Level up your DNA know-how
Short, honest guides for the terms that every DNA match conversation depends on.
What Is a Centimorgan?
The unit behind every shared-DNA number — and why it is not a percentage.
8 min read
Autosomal DNA Explained
What autosomal testing can and cannot tell you about your family.
9 min read
DNA Segments and Why They Matter
Half-identical regions, segment size, and the difference between one big segment and many small ones.
8 min read
Triangulation for Genealogists
Using three-way segment overlap to tie a match to a specific ancestral line.
9 min read
Local DNA Explorer
Open your raw DNA file without handing it to anybody
Download the raw genotype file your testing company already offers you, pick it from your disk, and DNADojo will identify the format, report the reference build, count the SNPs and let you search by rsID or chromosome — all in your browser.
- Format and build detected automatically
- Streaming parse in a Web Worker, cancellable at any time
- Nothing saved unless you ask; one button wipes it
- Zero third-party scripts on the Explorer page
Coming later
A research workspace, for when the free tools stop being enough
Match notebook, relationship hypotheses, projects that sync across your devices — and still no raw DNA in the cloud. Planned at $49 a year once the free tools have proved themselves.
Questions people ask first
Is DNADojo free?
Every calculator and every guide on this site is free and works without an account. A paid research workspace is planned, but the tools that answer "what relationship is this?" stay free.
Do I have to upload my DNA file?
No. The calculators need nothing but a number you type. The Local DNA Explorer reads a file you pick with your browser’s file picker and parses it on your own device — the file is never sent to a DNADojo server.
Will DNADojo tell me about health risks?
No, deliberately. DNADojo covers genealogy and education only: relationships, segments, and how to reason about them. It does not provide disease risk, carrier status, medication guidance or any clinical interpretation.
Which testing companies does this work with?
The calculators work with a shared-cM number from any platform. The Explorer targets the plain-text raw genotype downloads that consumer testing companies provide, and detects the format automatically.
Relationship dataset v1.0.0-simulated, last reviewed 2026-09-14. Sources, limits and changelog.