PNGMender

Auto-crop · pad · square

Trim transparent PNG

Crop away the empty transparent space around icons, stickers, cut-outs and renders, then pad them evenly or centre them on a square canvas.

Cropped in this tab. Nothing is uploaded.

Drop images to trim

PNG, WebP or GIF with transparent edges, or any image with a plain border.

Trim

Border to remove
0

Pixels this transparent or more count as empty. Raise it to ignore faint shadows and stray specks.

4

The border colour is taken from the top-left pixel.

px

How trimming works

The trimmer scans each image for the smallest rectangle that holds every visible pixel and crops to it. In Transparent mode a pixel is empty when its alpha is at or below the threshold; in Uniform colour mode it is empty when it is within the tolerance of the colour in the top-left corner, which suits scans and exports on white.

After the crop, padding adds the same margin on every side (transparent, or the border colour in uniform-colour mode). Square canvas then extends the shorter side, and the position setting decides where the image sits: centred for app icons and avatars, bottom-aligned for product shots that should share a baseline.

Every file in the batch uses the same settings, and changing a setting re-trims them all. The preview marks the crop with a dashed box over the original.

Tips

  • Soft drop shadows fade out slowly; an alpha threshold of 10–30 trims the nearly invisible fringe without cutting the visible shadow.
  • For sprite sheets and icons, keep the threshold at 0 so no partially transparent edge pixel is lost.
  • Photos and JPEGs have noisy borders; use uniform-colour mode with a tolerance of 8 or more.
  • Need the background gone first? Use Make PNG transparent, then trim the result.

Questions

Does trimming reduce quality?

No. The kept pixels are copied exactly and saved as a lossless PNG. Only the empty border is removed or added.

Why did nothing get trimmed?

Something touches the edge: often a nearly invisible pixel or a faint shadow. Raise the alpha threshold a little, or in uniform-colour mode raise the tolerance.

What happens to a completely empty image?

If no pixel passes the threshold there is nothing to keep, so the file is reported as empty and left out of the ZIP.

Can I trim many files at once?

Yes. Drop as many as you like; they are trimmed in background workers with the same settings and can be downloaded together as a ZIP.

Are my images uploaded?

No. Everything happens in this browser tab and your files stay on your device.

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