Colour Blindness Simulator
See how images look with protanopia, deuteranopia, tritanopia and achromatopsia. Free, private and instant: it runs entirely in your browser.
- Processed locally
- No upload, no wait
- No sign-up
- No watermark
Drop images here
or choose files · paste with Ctrl/⌘ V
JPG, PNG, WebP, HEIC, AVIF, GIF, TIFF, SVG, RAW, PSD, JXL, BMP, ICO and more
How to use Colour Blindness
- 1
Drop your images, choose files, or paste from the clipboard.
- 2
Adjust the options. The preview updates as you change them.
- 3
Click Simulate. Files are processed on your device.
- 4
Download each result or everything as a ZIP.
Why use Aback Images for colour blindness
Processed on your device
Your images are decoded, edited and encoded inside this browser tab by Web Workers. Nothing is uploaded to a server.
Instant results
Everything runs locally in a background thread, so there is no upload queue and no waiting on a server.
Batch friendly
Process many images at once and download them individually or as a ZIP.
Every format
Works with JPG, PNG, WebP, AVIF, HEIC, GIF, TIFF, SVG, RAW and more, identified by content rather than file name.
Related tools
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Group exact and near-duplicate images with perceptual hashing and see how much space they waste.
Re-save a JPEG at a known quality and see where its compression error differs: a heuristic hint at edited areas, not proof of tampering.
Separate an image into its red, green, blue and alpha channels as greyscale images, for masks, texture packing and colour checks.
Shrink JPG, PNG, WebP, AVIF and GIF files with MozJPEG, OxiPNG and modern codecs, with a live before/after preview.
Frequently asked questions
Are my images uploaded anywhere?
No. Processing happens inside your browser with WebAssembly and Web Workers. The site only downloads the app code and codecs; your files never leave your device. You can confirm this with the live upload counter on the tool, or in your browser's network panel.
Can I process many files at once?
Yes. Drop a whole selection or folder. Files are processed in parallel on several worker threads, each result can be downloaded on its own, and everything can be saved as one ZIP.
Is it free? Is there a file limit or watermark?
It is free with no account, no watermark and no daily limit. The only limit is your device's memory: very large images (over roughly 100 megapixels) may be refused to keep the tab from crashing.