answers, and a way to reach us.

Archie looks for the exact building first, in a database of 826,291 buildings: landmarks and listed buildings across the US and Europe from Wikidata, plus the historic-building registers of New York City and 44 other US cities.

With the photo's location, it finds the buildings along the camera's line of sight. Without one, it reads the photo itself (signs, house numbers, the shape of the building) and suggests names. Each name is checked before you see it, against a reference photo of that building or against its address and position. A name that doesn't pass isn't shown.

When the database has no match, Archie searches the web, using what it read in the photo and where it was taken. The style comes from your photo, matched against 146 styles.

Archie gets the style right, or picks a close relative of it, on 88% of photos in our style test, which has a labeled photo for each of our first 100 styles. Buildings that mix styles or were heavily remodeled are the hardest.

For the exact building, in our latest test Archie named the right one on 18 of 20 photos of known buildings taken without location, and on all 10 taken with location. It named no wrong building. Archie would rather say nothing than guess: a name it can't check isn't shown, and you get the style alone.

From sources read at the time, not from a model's memory. For a named building, Archie writes the history from the building's Wikipedia article or, when it has none, from web pages about it and its city's register record, and links what it used. A sentence with a year, a height or a cost that the sources don't give is cut before you see it.

The field guide on this site is Archie's own catalog: 146 styles and their histories, 139 features and 50 architects, with dates and attributions checked against Wikipedia or another reliable source.

Keep the location in your photos. Where the photo was taken, and which way the camera faced, is the strongest clue Archie has to the exact building.

Stand back far enough to fit the whole front of the building, with its entrance and house number if you can: Archie reads signs and numbers. Shoot in daylight with the camera level.

Your photo goes to Archie's server, which sends it to Google's Gemini to read it and, when Archie searches the web, to OpenRouter. It isn't kept on our servers unless it's saved to your library (photos you identify on this website are) or you report an identification as wrong.

The photo's exact position and direction are used only while that one request is handled, to find the buildings in front of the camera. A saved photo keeps where it was taken, rounded to about 11 meters.

Not on the iPhone: identification works without one. Saving to your library, your LifeList and the map need one, and so does identifying a photo on this website. Sign in with Apple, Google or a code sent to your email. Everything you save shows up on every device you sign in on.

Everyone gets 3 free identifications, and the field guide, your library and your LifeList are free to read. Archie Unlimited removes the limit, opens every place on the map and answers your own questions about a building. It's $19.99 a year with a 7-day free trial, or $49.99 once. Bought in the iPhone app, it works on this website too when you sign in with the same account.

The lifetime unlock never renews, so there is nothing to cancel. A subscription bought in the iPhone app is managed by Apple: on your iPhone, open Settings, tap your name, then Subscriptions. Cancel at least 24 hours before a free trial ends and you won't be charged; cancelling a paid plan keeps it until the period ends.

The 146 styles cover buildings around the world, from Ancient Greek to Japanese and Mughal, and the building database covers the US and much of Europe. The map covers 135 US cities so far.

Not yet. On Android, or on any computer, sign in on this website and upload a photo: Archie identifies it the same way and saves it to your library.