Configure a web tile layer

Before you share a web tile layer, you can configure it to specify a tiling scheme, the levels of detail to cache, the caching method and location, and other properties. This workflow explains how to modify the default configuration of a web tile layer. To begin the sharing process, set general properties, and finish sharing, see Share a web tile layer.

You may also configure a web tile layer when you configure a web map, web scene, or web link chart. The information in this topic applies in those situations also.

1. If necessary, open the Share As Web Layer pane.

   On the General tab, confirm that Tile is selected.

2. Click the Configuration tab.
3. Click the Tiling Scheme drop-down arrow and choose a tiling scheme for your cache.

   The tiling scheme determines the number of levels of detail, the tile dimensions, and the tile origin of the cache. These settings in turn define tile boundaries and must be the same for different web layers used in a web map. Only the extent defined in the map properties is cached. The available tiling schemes are described in the following table:

   Option	Description
   ArcGIS Online/Bing Maps/Google Maps	The web layer is projected to the WGS 1984 Web Mercator (Auxiliary Sphere) coordinate system. The default tile width and height is 256 by 256 pixels. Scale levels for caching range from zero to 23.
   WGS 1984 Geographic Coordinate System, Version 2	The web layer is projected to the WGS 1984 Geographic Coordinate System. The default tile width and height is 256 by 256 pixels. Scale levels for caching range from zero to 22.
   Existing cached map/image service	The tiling scheme of an existing hosted tile layer, or an existing ArcGIS Server map or image service, is used. The tiling scheme XML file of the layer or service is downloaded to C:\Users\<user profile>\My Documents\ArcGIS\TilingSchemes\Downloaded. ArcGIS AllSource honors the parameters specified in the existing layer or service, with the exception of antialiasing. Antialiasing options set for the application are used.
   Tiling scheme file	A tiling scheme that you create is used. You can create a tiling scheme XML file with the Generate Map Server Cache Tiling Scheme geoprocessing tool. Additional tiling scheme files can be imported from C:\Program Files\ArcGIS\Pro\Resources\TilingSchemes. The tile image format defaults to PNG if the tile image format is not defined in the tiling scheme file. ArcGIS AllSource honors the parameters specified in the tiling scheme file, with the exception of antialiasing. Antialiasing options set for the application are used.
   Auto-suggest	This is the default option unless the coordinate system of your map is WGS 1984 Web Mercator (Auxiliary Sphere) or WGS 1984. A tiling scheme is suggested based on the coordinate system of your map or scene. The levels of detail defined in this tiling scheme are valid for a global extent, so any web layers cached using this tiling scheme can be displayed together.

   Note:

   If you are configuring these properties when sharing a web scene or web link chart, the tiling scheme is defined by the basemap if one is present. In the absence of a basemap, the tiling scheme is defined by existing cached web layers. If there are no existing cached layers, a tiling scheme is automatically suggested based on the scene or link chart's coordinate system.

4. Under Levels of Detail, use the sliders to set the map scales for which tiles are generated.

   A default scale range is provided. Depending on the purpose of your map and the estimated cache size, you can choose not to cache some very large or small scales.

5. For Image format, accept the default or choose a different setting. Use the following table for reference.

   If all sublayers in the web layer have vector data sources, the default setting is PNG. If one or more sublayers has a raster data source, the default setting is MIXED.

   PNG	Use PNG to select the correct format (PNG8, PNG24, or PNG32) automatically based on the levels of detail that are being cached.
   PNG8	Use PNG8 for overlay layers that need a transparent background, such as roads and boundaries. PNG8 creates tiles of very small size on disk with no loss of information. Do not use PNG8 if your map contains more than 256 colors. Imagery, hillshades, gradient fills, transparency, and antialiasing may cause your map to use more than 256 colors. Symbols such as highway shields may have antialiasing around the edges that unexpectedly adds colors to your map.
   PNG24	Use PNG24 for overlay layers, such as roads and boundaries, that have more than 256 colors. If fewer than 256 colors are used, choose PNG8.
   PNG32	Alternatively, use PNG32 for overlay layers, such as roads and boundaries, that have more than 256 colors. PNG32 is a good choice for overlay layers that have antialiasing on lines or text. PNG32 creates larger tiles on disk than PNG24.
   JPEG	Use this format for basemap layers that have large color variation and do not need a transparent background. Raster imagery and detailed vector basemaps tend to work well with JPEG. JPEG is a lossy image format. It attempts to selectively remove data without affecting the appearance of the image. This can cause very small tile sizes on disk, but if your map contains vector line work or labels, it may produce too much noise or blurry area around the lines. If this is the case, you can increase the compression value from the default of 75. A higher value, such as 90, may balance an acceptable quality of line work with the small tile size benefit of the JPEG.
   MIXED	The MIXED format uses JPEG in the center of the web layer and PNG32 on the edges. Use MIXED to overlay raster layers on other layers. When the MIXED format is used, PNG32 tiles are created anywhere that transparency is detected (in other words, anywhere that the map background is visible). The rest of the tiles are built using JPEG. This keeps the average file size down while providing a clean overlay of raster layers on top of other layers. If you do not use the MIXED format in this situation, you will see a nontransparent collar around the edge of your image where it overlaps other layers.

6. For Compression, accept the default compression quality value or specify a different value.

   Compression is available only if the format is JPEG or MIXED. (PNG formats are not compressed.) Values between 0 and 100 can be used. Higher values result in larger file sizes with higher quality imagery. Lower values result in smaller file sizes with lower quality imagery. The default value is 75.

7. Under Options, choose how to build the cache.

   The storage estimate under Estimate at the bottom of the pane may help you decide how to build the cache.

   Cache automatically on the server	If the cache is small, it is recommended that you build the cache automatically. This is the default setting.
   Cache manually on the server	If the cache is large, it is recommended that you build the cache manually, caching the largest scales at selected areas of interest that are most likely to be visited. You can build the cache manually from the ArcGIS Online website or ArcGIS Enterprise website.
   Cache locally	Use this option to minimize the credits used when you share to an ArcGIS Online portal or to minimize resource consumption when you share to an ArcGIS Enterprise portal. The local cache is temporarily saved as a tile package (.tpkx) that is then uploaded and unpackaged automatically. Note: When publishing to ArcGIS Online, the .tpkx file will not be added as an item in your organization if it is larger than 100 GB.

   1. If you chose Cache locally, accept the default Temp cache location, which is determined by your share and download options settings, or browse to a different location.

   Note:

   When you save a service definition, the cache must be built manually after the web tile layer is published.

8. Optionally, check the Allow clients to export cache tiles check box to allow clients to download map tiles for offline use.

   When this option is turned on, you can specify a value in the Limit export to box to limit the number of tiles that can be downloaded in a single request.

   Note:

   If you cache locally, the option to allow clients to export cache tiles is not available if your ArcGIS Enterprise version is 10.5 or earlier.

9. Optionally, under Estimate, click Calculate to estimate the cache size. On the Estimate Cache Size dialog box, click the drop-down arrow and choose Good or Best for the estimation quality. Click the Start estimating cache button . The number of tiles and storage space is estimated for each cached level of detail and totaled. Click OK.

   The default static estimate is based on a general assumption about average tile size and does not consider the specific properties of your map. When you estimate the cache size, sample tiles of your map are built. This means that the tiling scheme, image format, and compression are taken into account (as is LERC compression for elevation layers).

   The best estimate creates more sample tiles and takes longer to calculate than the good estimate. To cancel the estimation process, click Stop estimating cache . If you adjust the tiling scheme after estimating the cache size—for example, if you change the levels of detail or the image format—the quality estimate on the sharing pane reverts to static. You need to estimate the cache size again.