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Auto-Trim Transparent Edges from PNG

auto bounding box · removes empty space around content · batch · in-browser

Drop PNGs with transparent borders and the tool finds the tight bounding box around the actual artwork and crops to it — removing the empty space around logos, icons, stickers, signatures, and sprite frames. Adjust the alpha threshold to also strip near-transparent anti-aliased halos. Runs entirely in your browser, batch-ready, with no upload.

Drop PNG files here

Multiple files allowed

    no files
    Ready.

    Picking the alpha threshold

    A pixel is treated as empty when its alpha is at or below the threshold:

    When to use auto-trim

    FAQ

    Can it trim a solid white (non-transparent) border?

    Not directly — auto-trim works on the alpha channel, so it removes transparent space, not coloured space. To trim a solid white margin, first make white transparent with Background (remove mode), then auto-trim. For a known fixed margin, Crop by coordinates is faster.

    What if my image is fully opaque?

    Nothing is trimmed — output is the same dimensions as the input.

    What if my image is fully transparent?

    The tool reports "all transparent — nothing to trim" and skips that file.

    Will it crop into the actual content?

    No (at threshold 0). Only fully-transparent edge pixels are dropped — interior content is untouched. At higher thresholds you can lose feathered edges; bump down to 0 if you see clipping.

    What about JPG inputs?

    JPG has no transparency, so there's nothing to trim — auto-trim is a PNG-only operation. To trim a uniform-coloured border (e.g. solid white) instead, use Crop with measured coordinates.