It's at https://husforhus.se, in English and Swedish.
You can drag a timeline to watch the city grow, search for any address, and open a card for each of the 77,743 buildings in the municipality: its year, where the year comes from, and for about 900 notable buildings a photo and a short Wikipedia text.
A few notes:
- Over half the buildings have no recorded year in open data, so they show as "Year unknown" rather than a guess. Ironically the oldest part of town has the biggest gaps: 77% of Gamla stan's buildings have no year in the open registers, against about 10% in Östermalm.
- Private houses show only their decade, never the exact year or an owner.
- It's all open data (City of Stockholm, Riksantikvarieämbetet, OpenStreetMap, Wikidata) and open source (star and contribute here - https://github.com/amirelion/husforhus), with no cookies or tracking.
If you know the year of a building that's wrong or missing, the card has a "Something wrong?" link, and corrections with a source are very welcome.