DuoNat
A visual taxon identification game
Grow Earth's biodiversity in your mind.
DuoNat pairs up real photographs from iNaturalist and asks you to match each taxon to the right image. Experience Earth's amazing biodiversity wherever you are.
How it works
Pick a place or a group of life forms you're curious about — birds in your backyard, wildflowers, mushrooms, insects, whatever comes to mind. DuoNat shows you two real photos and two names, and asks you to match them up.
That's where the fun starts: playing detective. Two animals or plants that look almost identical at a glance — what actually sets them apart? A patch of color, the shape of a leaf, the way a wing folds. Round by round, you test your ideas, until you're confident. Then swipe left for a new pair.
Along the way you explore the astonishing richness of life on Earth — every round with real, wild photographs from the iNaturalist community.
Play a round now Free, no account, runs in your browser.
Or start with one of these
Each one opens DuoNat with the filters already set — a small, finishable group rather than all of life at once. Change or clear them whenever you like.
Parrots
Macaws, amazons and conures, easiest level, species against species. A good first hour.
Butterflies of Ecuador
One country, one group. Swap Ecuador for anywhere you're going — this is what the country filter is for.
Lichens, up close
Crusts and rosettes on bark, walls and gravestones. Easiest level — and once you start noticing them, you can't stop.
A look inside
Who it's for
Curious naturalists
Practice the calls that trip you up in the field: which warbler, which aster, which of two near-identical bees.
Students & self-learners
Turn a taxonomy unit or a personal deep-dive into a group of taxa into an engaging game.
Kids exploring nature
Start at the easiest level, where the two are plainly different, and enjoy the first "wait, those aren't the same animal?"
…or just start
Take one of the starter kits above, or open the app and see what turns up. Free, no account, runs in your browser.
Help it grow
The tree of life is vast, and DuoNat has mapped a corner of it so far — the stats page shows exactly how far, clade by clade. It is free, ad-free and made by volunteers, and the only real running cost is bandwidth for photographs: about a dollar a year for someone playing half an hour a day. Five bucks carries five of us for a year.
Chip in on Ko-fi No five bucks to spare? Tell one fellow nature-lover, or come say hi on Discord and tell us what's missing. Both help more than you'd think.