Where playground data comes from.
A playground map looks like a single thing. It is not: it is several datasets of very different quality stitched together, which is why one city shows the equipment of every playground and the next one shows only dots.
OpenStreetMap: the base layer.
Most playgrounds on any map come from OpenStreetMap, the open map built by volunteers since 2004. Someone walked past, drew the area, and tagged it as a playground. That is usually where it stops: a location, sometimes a name, rarely anything else.
This is why a map can know that a playground exists and nothing about what is in it. The data is only as detailed as the person who mapped it decided to be, and most mappers are not parents standing there with a checklist. OpenStreetMap data is open under the ODbL licence, which is why apps can use it at all, and why they have to credit it.
Municipal open data: the deep end.
Some cities publish their own playground registers, and those are a different level of detail. The City of Vilnius, for example, publishes 719 playgrounds with photos, the area in square metres and the age group each one was built for. That is a level of information no volunteer mapper would ever add by hand.
The catch is that only a minority of cities do this, and every register has its own format, its own fields and its own idea of what a playground is. Merging them into one map is most of the work behind an app like KidMap.
Families: the part nobody else records.
Whether there is a baby swing, a fence, shade or a toilet is almost never in the official data. It is known only by the people who went there. In KidMap, parents mark equipment, add photos and rate what they found, and that is the layer that makes a map useful rather than complete.
Why the map looks uneven.
Take four real examples from the same dataset. In Madrid, 1,761 of 2,215 playgrounds have their equipment recorded, because the city's own data carries it. In Ottawa, 503 playgrounds are recorded with a baby swing. In New York City, 843 have water play, which matches how many splash pads the parks department runs. In Riga, 213 playgrounds are mapped and not one has equipment recorded.
None of that means Riga's playgrounds are empty. It means nobody has written down what is in them yet. When you read any playground map, the honest reading of a missing detail is "not recorded", never "not there".
How to fix something that is wrong.
If a playground is missing, wrong or gone, it can be fixed at the source. In KidMap you can correct a playground, mark its equipment and add photos, and the change helps the next family. For the map underneath, anyone can edit OpenStreetMap directly, and every app using that data picks the change up in time.
The full list of sources KidMap uses, with their licences, is on the data sources page.
Common questions
Where does KidMap get its playground data?
From OpenStreetMap under the ODbL licence, from municipal and government open data where a city publishes it, from Wikimedia Commons for some photos, and from families using the app who add equipment, photos and corrections.
Why do some playgrounds have no equipment listed?
Because nobody has recorded it yet. Open map data usually holds only a location, and equipment is added either by a city that publishes its own register or by parents who visit. A missing detail means "not recorded", not "not there".
A playground on the map is wrong. How do I fix it?
Correct it in KidMap: you can fix the details, mark equipment and add photos. The underlying map can also be edited by anyone at OpenStreetMap, and those changes reach every app that uses it.
Your next playground is already on the map.
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