Every time I export an image as PNG, I get stuck at the “compression level” prompt. The options go from 0 to 9, and I always forget what each one actually does.

So, I’m jotting this down for my own reference (and maybe yours).

Why not just use JPG? PNG is lossless and supports transparency. Handy for things like signatures or overlays.

Quick notes:

  • Compression levels: 0 (none) to 9 (max)
  • Quality: All levels are lossless, but higher compression takes longer
  • File size: 0 = biggest, 9 = smallest

Here’s how I think about it:

  1. Level 0 (No Compression): Fastest save, biggest file. Good if you’re in a hurry or don’t care about size.
  2. Levels 1-2 (Minimal Compression): Slightly smaller files, still quick.
  3. Levels 3-5 (Balanced): My usual pick. Decent size, not too slow.
  4. Levels 6-7 (Moderate): Smaller files, a bit slower. Use if you’re uploading lots of images.
  5. Levels 8-9 (Maximum): Smallest files, slowest save. Only worth it if you really need to squeeze out every byte.

I usually stick to level 5. If I’m archiving, I might go higher.

That’s it—just some notes for future me. If you have a better rule of thumb, let me know.