What it does
Overpass API lets a client ask the OpenStreetMap database for a selected set of nodes, ways, and relations rather than downloading the whole map. Queries can combine tags, geographic bounds, and object types, with results returned in machine-readable formats such as JSON or XML. Public instances make small queries convenient, while larger or commercial workloads need a more deliberate hosting plan.
Ask for a slice, not the whole map
Overpass is useful when a task needs a particular kind of mapped feature in a particular area, such as public drinking-water points in a city. The manual's quick-start route uses the separate Overpass Turbo interface to turn a plain-language search such as “Drinking Water in London” into a query; a program can then send an Overpass QL request to the API's interpreter endpoint and ask for JSON or another documented output format. Overpass Turbo is a query client, not the API itself.
A practical first request should narrow both the geography and the tags, then return only the object detail your application needs. This avoids fetching irrelevant map data and makes a result easier to cache. The API is not a map renderer, geocoder, or routing engine; it returns matching OpenStreetMap objects for downstream code to interpret.
Shared instances have a budget
The public servers are shared by many users. The documentation describes free public access for light use, but warns about load shedding and says the main instance can be overloaded. It recommends caching, identifying the client, avoiding parallel scripts, and using extracts, a self-hosted instance, or a paid provider when an app needs substantial or commercial use. The service documentation gives approximate request and data-volume guidance, not a guaranteed service level.
The server software is licensed under GNU AGPL v3. That is separate from the terms and attribution requirements that apply to OpenStreetMap data returned by a query. This entry covers the API and its public instances, not the Overpass Turbo browser interface.
Strengths
- Combines object type, tags, and spatial filters to return a focused subset of OpenStreetMap data.
- The documented interpreter accepts programmatic queries and supports machine-readable output.
- A public endpoint is available for modest exploratory and application use.
Watch out for
- Public instances are shared, can shed load, and are not presented as a high-reliability service.
- Heavy or commercial use should move to a self-hosted or paid service rather than depend on the public pool.
- Clients need to understand Overpass QL or use a separate query-building interface such as Overpass Turbo.
Best for
- Finding points of interest or mapped infrastructure by OSM tags within a chosen area.
- Building a small geographic data prototype that can cache results and tolerate shared-service limits.
- Developers who need to query selected OpenStreetMap objects by tags or location.
Sources
- Overpass API - OpenStreetMap Wiki (Oct 26, 2026)
- Overpass API User's Manual (Oct 26, 2026)
- Commons (Oct 26, 2026)