I want to divide a polygon layer into different smaller polygons. I started by converting the main polygon into a line, then I used the Add line feature to draw the lines. Then I used the Split with lines from the toolbox. However, it didn’t split them all as you can see. (Probably because not all the lines 'intersect or touch the original polygon line)

Lines Layer: enter image description here

Split layer: (I even tried Dissolve first) enter image description here

I also tried using the Polygonize in the Processing Toolbox. It does not split the existing polygon but creates a new layer with all the polygons which are enclosed by the lines of the another. It is fine with me, but the fields in the attribute table were empty even though I chose Keep fields from input layer like this (the first table is from the Polygonize tool, the second one from the original lines layer

enter image description here

How can

  • 1
    You could join attributes by location afterwards.
    – Erik
    Commented Jun 2, 2021 at 8:30
  • 1
    and the answer was just simple as that! But why the split by lines didn't work? is it because the lines don't intersect with the original polygon as I suspect?
    – wollyka
    Commented Jun 2, 2021 at 8:34
  • Maybe because you didn't dissolve the lines before splitting.
    – Erik
    Commented Jun 2, 2021 at 8:35
  • I also try it, same results. Anyhow, Polygonize solved the issue but the attributes disappearing was problematic
    – wollyka
    Commented Jun 2, 2021 at 8:40
  • 1
    Geoprocessing tool Union should also do the job, without first converting to lines - just big polygon + smaller polygons as input layers.
    – Babel
    Commented Jun 2, 2021 at 9:16

1 Answer 1


As mentioned in the comments Polygonize with join attributes by location is a workaround!

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