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OS OnDemand Web Map Service

OS OnDemand Web Map Service is no longer available for new users and will be withdrawn on 22nd November 2021.

OS OnDemand Web Map Tile Service is no longer available for new users (being withdrawn in November 2021). We have now launched a new suite of APIs, accessible from our new data access platform, OS Data Hub.

Try our new APIs

On the OS Data Hub, you can sign up to a Premium Plan and benefit from £1,000 of free premium data a month. This gives you free access to a new suite of mapping and feature APIs for your apps, including OS Maps API, our new Web Map Tile Service. Signing up to the Hub will also give you access to OS Vector Tile API (a Vector Tile Service) and OS Features API (a Web Feature Service) plus more.

Analysing map data

Accessing OS OnDemand via a GIS

We are working with our partners to ensure their systems are OpenGeospatial Consortium (OGC) compliant and have a list of compliant software providers available. If you do not have a GIS system, we are unable to recommend either suppliers or software products, as the most appropriate system will depend on many factors.

Known issues with compliant software

We are aware there are issues with a small number of GIS systems and we have been working with system suppliers to remedy this. In the meantime if you are experiencing problems please contact your system supplier.

For example we are aware of the issue with connecting to the service using ArcGIS 9.2. Unfortunately, this cannot be corrected for use in ArcGIS 9.2, but has been fixed in ArcGIS 9.3.

To connect to the service using ArcGIS 9.2, we suggest you embed your username and password into the URL. For example,

The scale at which the layers activate in ArcMap changes based on the size of the map window being used. It is a function of the way the mapping is delivered.

If your GIS provider is not OGC compliant for web services and OS OnDemand, then you may want to recommend that they apply for a OS OnDemand Developer Partner licence.

If you are an ESRI ArcGIS user, with OS OnDemand already set up in your Table of Contents window, you may need to refresh the table to see newly added layers following a service upgrade.

To do this right click on the OS OnDemand WMS and click remove. Then double click on the OnDemand GIS server in the Catalog to connect to it and then pull over the OS OnDemand WMS service to the Table of Contents.

Accessing via a browser

You can access OS OnDemand WMS service via a web browser using JavaScript like OS OpenSpace. Web toolkits such as OpenLayers or MapFish can be used and will pull in the WMS. See below for examples of this:

Known issues with browser compatibility

If you are using Windows® 7 and your username and password is no longer accepted, then type it in rather than cut and paste.

If you have installed Internet Explorer 8 and the OS OnDemand WMS is no longer displaying the map, you will need to utilise the Developer Tools (using the Tools | Developer Tools menu option [or by pressing the F12 key]. You should have a choice of three Browser Modes in the menu bar [Internet Explorer 7; Internet Explorer 8; and Internet Explorer 8 Compatibility View]. The pages will generate an error message when using Internet Explorer 8 setting – whilst the page works as expected with the other two options.

There is also additional improved security introduced with IE8 which prevents username and password details from being hard coded into the request. To get around this you could use which is used to construct the request string which is then called from the html.

If you are using a Flash application to access OS OnDemand WMS through IE7 or above, across an authenticating proxy the authentication details for OS OnDemand WMS will be removed. This will result in the need to re-enter the username and password. This is caused by a bug in Microsoft IE. If you have this set-up or use this combination, we would suggest you use an alternative web browser.

Most map requests of 500 x 500 pixels will be delivered in under two seconds. However, larger images of say a layer of OS Mastermap Topography may take up to four seconds. Where there are delays, it is advisable to check your Internet security settings.

Generally, making requests in any coordinate system other than GB National Grid can result in slower response times.

Mapping layers

The following mapping layers are available through OnDemand WMS:

Product Index Optional style
OS MasterMap Topography Layer (raster format image) MMAREA MMAREA2
OS MasterMap® Topography Line (raster format image) MMLINE MMLINE2
OS MasterMap® Boundary-Line (raster format image) MMBDY MMBDY2
OS MasterMap® Cartographic Symbol (raster format image) MMSYM MMSYM2
OS MasterMap® Topographic Point Symbol (raster format image) MMPT MMPT2
OS MasterMap® Cartographic Text (raster format image) MMTXT MMTXT2
OS MasterMap® Integrated Transport Network™ Layer Road Networks theme (raster format image) MMITNR MMITNR2
OS MasterMap® Imagery Layer (25cm) IMA25  
OS MasterMap® Integrated Transport Network™ Layer Urban Paths theme (raster format image) MMITNP  
OS VectorMap® Local Colour Raster VMLCRAS  
OS VectorMap® Local Black & White Raster VMLBWRAS  
OS VectorMap® Local Backdrop Colour Raster VMLBCRAS  
OS VectorMap® Local VML  
1:25 000 Scale Colour Raster 25K  
1:50 000 Scale Colour Raster 50K  
Land-Form Profile® Contours PROCONT  
Land-Form Profile® DTM PRODTM  
*GB Overview+ OV1  
*GB Overview OV0  
OS OpenData™ products:    
OS VectorMap® District VMD  
1:50 000 Scale Gazetteer GAZ  
1:250 000 Scale Colour Raster 250K  
Boundary-Line™ BL  
Land-Form PANORAMA® Contours PANCONT  
Meridian™ 2 M2  
MiniScale® MS  
OS Locator™ LOC  
Strategi® STRAT  
OS StreetView® (1:10 000 scale) SV  

If a blue mask is shown, normally this would indicate that you are not licensed for the Ordnance Survey map data for this area (e.g. you do not hold the required PSGA or Framework Direct licence). In the case of the Isle of Man the intellectual property for these more detailed maps is held by the Isle of Man government and as such, Ordnance Survey does not have a licence to be able to serve these maps within OS OnDemand. The following products are available for this area: GB Overview+, GB Overview, MiniScale®, 1:250 000 Scale Colour Raster, 1:50 000 Scale Colour Raster, Land-Form PANORAMA® DTM, Land-Form PANORAMA® Contours and Strategi®

Working with OS MasterMap layers

When requesting the Topography layer, you will notice that you do not see lines, texts and points. This happens because the topographic areas are being rendered on top of the other requested layers thus concealing them from view when the image is generated within the service. In order to see all the components, the topographic area must be requested first followed by the others, so that these are drawn on top.

When requesting multiple OS MasterMap layers, it is recommended to request them in parallel. This will result in an overall faster response time than if multiple layers are treated as a single request.

When requesting the Imagery layer, you may notice black areas around the coast or river estuaries. These are areas that we do not capture during our aerial flying programme and so any area for where there is no data is shown as black. Our flying schedule runs from March to November and we capture many parts of the country at different times of the year. When viewing OSMasterMap® Imagery layer at a small scale some differences in colour will be visible due to seasonal changes in the landscape.

Working with multiple 'same scale' mapping layers

Requesting 'same scale' raster products will result in slower response times and the service will default to show OS Street View. When viewing same scale raster products you should only select one at a time and you must select the product that is suitable for your application.

Working with Strategi and Meridian2 mapping layers

When using Strategi and Meridian2, the features from Strategi will overlay on top of Meridian2 features, as when two or more products are requested in one get-map-request, they are returned as a single image. If one or more of the requested products is a multi-layer vector product, then the text relating to each product will be present as above. It should be noted that there may be conflict between text occurring in different products. For products with licence masks, these masks will be applied directly after each of these products.