Image Transparent Trimmer

How to use

1. 1Drop an image onto the upload area or click to pick a PNG, WebP, GIF, JPG, or BMP file (up to 25 MB). PNG, WebP, and GIF carry transparency; JPG and BMP have no alpha channel and will not change unless they already contain transparent pixels.
2. 2Pick an alpha threshold. Strict (alpha = 0) is the safe default and trims only fully transparent pixels. Soft halo (alpha at or below 16) also removes the faint border left by anti-aliased erasers. Aggressive (alpha at or below 64) cuts deeper into shadows.
3. 3Optionally set a padding value to add a margin around the trimmed subject. 0 keeps the tightest possible bounding box; small values like 4 to 16 px add breathing room for icons and stickers.
4. 4Pick an output format: Keep original, PNG (lossless), WebP, or JPEG. For JPEG, choose a background color that will fill the formerly transparent area.
5. 5Click Trim and export. Inspect the result in the preview, then click Download trimmed image to save it. Tweak any setting and click Re-render with current settings to update the output without re-uploading. Your image is not uploaded.

About this tool

Image Transparent Trimmer crops the empty transparent border around an image so the subject sits tight inside its canvas. Drop a PNG, WebP, or GIF (the three common web formats with an alpha channel) and the tool scans every pixel to find the smallest rectangle that still contains the visible content, then redraws the image at that rectangle. Useful for cleaning up exported stickers, logos, icons, signatures, cutout product shots, screenshot crops, and sprite-sheet frames that ended up with extra blank space around the subject because the source canvas was bigger than the artwork. An alpha threshold slider controls how transparent a pixel must be before it counts as background: leave it at 0 to trim only fully invisible pixels (the safe default for clean cutouts), raise it to 16 to also trim the nearly invisible halo that anti-aliased erasers and soft brush edges leave behind, or push it to 64 to cut into faint drop shadows when you want a hard, tight crop. A padding control adds an equal margin to all four sides after trimming, useful when you want a small breathing room around an icon, sticker, or logo before placing it in a layout. The trim preview shows the original dimensions, the dimensions after trim plus padding, and the percentage of pixels removed so you can confirm the crop before exporting. Output can keep the original format (PNG stays PNG, WebP stays WebP) or convert to PNG, WebP, or JPEG; PNG is always lossless, WebP and JPEG accept a quality slider, and JPEG (which has no alpha channel) fills the transparent area with the background color you choose, with quick presets for white, black, light and dark gray, the site navy, and warm cream, plus a free hex input and color picker. The trim computation runs at full resolution for images under the 8192 px working ceiling and at a proportional sample for larger inputs (the bounds are rounded outward so the subject is never clipped). Everything happens locally on a canvas: the image you drop is loaded into a local object URL, the alpha scan reads pixels from that local canvas, and the encoded result is delivered as a Blob to your browser. Nothing is uploaded.

Free to use. Works in your browser. No signup, no login.