OS MasterMap vs OS Maps: what's the difference?

In practice, OS MasterMap and OS Maps do different jobs. OS MasterMap is the underlying data, while OS Maps are map views that display the data. The difference matters because the right choice depends on what you’re trying to do.

• OS MasterMap is detailed geographic data. A highly accurate digital dataset detailing Great Britain’s physical landscape – including buildings, roads, paths, rivers, land use, and more.

• OS Maps, by contrast, usually means maps themselves that can be viewed, displayed, or used on screen – which might be in an app, on a website, or through a mapping service. 

Which one’s right for you - OS MasterMap or OS Maps? 

If you need precise, feature-level data for planning, analysis, asset management, infrastructure, or GIS and CAD workflows, then OS MasterMap is usually the right choice. It’s designed for detailed work at large scales and is available as vector data, ideal for use in GIS / CAD systems. 

If you need mapping that people can quickly see and use, OS Maps are often more appropriate. OS’s map products can show these maps as ready-made views, tiles, and styles that let you see and work with maps, without worrying about storing, updating, or managing large datasets yourself.  

The two are often used together. One provides detailed information, the other makes mapping easier to present, share, and work with.

In essence, OS MasterMap is for working with detailed location data, while OS Maps are for seeing and using mapping in a more immediate way. If you are choosing between them, the real question is whether you need the underlying data itself, or a map that helps you put geography to work.

OS MasterMap is one of Ordnance Survey’s most detailed digital datasets. In practical terms, OS MasterMap products - like OS Mastermap Highways Network - offers the authoritative, highly accurate view of Great Britain - verified details of more than 500 million real-world features across the physical landscape. Everything from buildings, roads and paths to rivers, fences, land parcels, and more. 

How Emapsite can help

Learn more about OS MasterMap products in our product pages and guides. We can also help you choose the right map for your project via email, chat or over the phone.

For more information, reach out to our Customer Support team.