Supported Geometry Types

One common reason is that the geometry data is too detailed and exceeds Power BI’s character limit (32,767 characters per cell). This means that if any geometry string (for example, a WKT or GeoJSON feature) in a single field exceeds 32,767 characters, Power BI will not display any rows for that visual — even if all other rows are valid. This limit applies to each individual cell in your dataset, not the total file size.

Here’s how you can avoid this issue:

• Reduce precision: Coordinates are often stored with a lot of decimal places, which is usually more detail than needed and makes the data longer. Rounding to 4 decimal places is accurate enough for most cases. In QGIS, you can do this efficiently with the ‘Snap to Grid’ tool in the processing toolbox.

  Example:

  // 8 decimal places (long)
  LINESTRING (13.36612345 52.53798765, 13.44567891 52.50012345)
  // 4 decimal places (short)
  LINESTRING (13.3661 52.5380, 13.4457 52.5001)

  The second version is much shorter and still accurate for most mapping purposes.

• Simplify the layer: If your shapes are generated by an algorithm (like catchment or river delineation), they may contain far more points than necessary, resulting in large data files. Simplifying the shapes can help, though it may slightly affect boundary accuracy.

• Use single geometries instead of multi-geometries: Instead of using MultiLineString or MultiPolygon, use individual LineString or Polygon geometries. If a LineString is too large, you can split it into several LineStrings and place each in a separate column. This reduces the size of each geometry and helps avoid character limits.