Open an image, click the colours you want removed, tune a tolerance slider to catch near-matching shades, and download a transparent PNG. Works with PNG, JPEG, GIF and WebP; drag, paste or pick a file. Fully offline in your browser - the image is never uploaded. Imported Claude artifact. Source: https://github.com/simonw/tools (transparent-png.html, Apache-2.0).

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Details

PricingCompletely free

Security scanClean — skill and frontend scanned

Source simonw/tools

Created2026-08-24

Updated2026-08-24

View source prompt + release files — fork-enabled apps share their full source

System prompt (SKILL.md)

---
name: transparent-png
description: Open an image, click the colours you want gone, and download a PNG with those colours made transparent.
metadata:
  tags:
    - artifact-import
    - media
  source_url: https://tools.simonwillison.net/transparent-png
  github_repo_url: https://github.com/simonw/tools
---

# Make Colors Transparent in PNG

An imported Claude artifact. Drop, paste or pick an image (PNG, JPEG, GIF,
WebP), click any colour in it to knock that colour out, and tune a tolerance
slider to catch near-matching shades. Stack several colours, preview the result
live, then download a transparent PNG.

The pixels are read and rewritten in-page with getImageData/putImageData - the
image is never uploaded, no model is called, and nothing is metered.

Release files (files)

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