Today I once again found myself needing to stitch screenshots together. It has been a while since I last had to do this (back then, I used some random app). Because I started using GIMP for more and more tasks, I wanted to do this in GIMP as well now.

Luckily, I found this Reddit post. I will repeat the steps here, both as a mental aid and in case that the original posts disappears. Also, I have slightly adjusted the steps.

  1. In another tool (e.g., Gwenview), crop the screenshots so that the top and bottom system bars that are in the overlapping regions are gone.
  2. Open GIMP
  3. File > Open the top most screenshot
  4. File > Open as Layers... all other screenshots
  5. ∀ layers: set opacity to ~50%. (Select layer in the layer list on the left, then click opacity bar above.)
  6. Image > Canvas Size...: liberally increase the canvas height. Make sure that “Resize layers” is set to “None”.
  7. Click M to select the Move tool
  8. ∀ layers: select the layer and use the arrow keys to move them up/down. Use Shift+⇅ for rough moving. Zoom in on the canvas to get the alignment pixel-perfect. Increase the canvas height again if necessary.
  9. ∀ layers: set the opacity back to 100%
  10. Image > Fit Canvas to Layers
  11. File > Export As...