Image workflows get messy fast. You finish a design review, export six separate PNGs, and then realize the client wants everything in one file. Installing a full editor for a one-off merge is overkill, and most desktop tools add watermarks or resize your images without asking.

That's why I keep a browser tab open for merging images. The workflow is simple: drop your files, pick a layout (vertical stack, horizontal row, or grid), adjust spacing if you need it, and export. No account, no upload queue, no "premium" nudge halfway through.

A good PNG merger handles the details that desktop tools get wrong: keeping transparency intact, preserving original resolution, and letting you reorder files by dragging instead of renaming them with number prefixes.

A few tips I've picked up:

  • Match widths before merging horizontally — mismatched heights get padded, and the padding color is rarely what you want.
  • For sprites, use a grid layout with even spacing so your CSS background-position math stays clean.
  • Keep the PNG format for UI screenshots; converting to JPEG to save space will eat your text sharpness.

The whole process takes under a minute once you have the layout figured out. For teams that ship UI screenshots regularly, that minute adds up — and nobody has to install anything.