Compare WebP Images
Compare two WebP images online, pixel by pixel. Works with lossy and lossless WebP, respects transparency, and groups differences into regions. No upload.
Files never leave your browser.
Drop two WebP files to compare pixel by pixel. Works for both lossless and lossy WebP. Alpha is honoured; tolerance handles compression noise on lossy inputs.
About WebP Diff
Compares two WebP images pixel by pixel in your browser. Lossy and lossless WebP are both decoded to RGBA first, so files that use different modes still compare, transparency included.
How to use
- Drop or pick the left WebP file.
- Drop or pick the right WebP file. A mask marks every pixel that changed.
- For lossless WebP keep Color tolerance at 0. For lossy WebP raise it until the encoder noise stops showing.
What this tool doesn't handle
- An animated WebP is read at its first frame. Save the frames you need as single images to compare them.
- Only the decoded pixels are compared. The WebP mode, the quality setting and the metadata chunks are not reported.
Frequently asked questions
Do my files ever leave my browser?
No. Every comparison runs locally in your browser. Nothing you paste, drop, or load is uploaded to a server; the tool keeps working even if you go offline after the page loads.
Is this tool free to use?
Yes. All DiffResolver tools are free, with no account, sign-up, or installation. Because processing happens on your device, there are no server-imposed usage limits.
Does this work with lossy and lossless WebP?
Yes. The browser decodes both modes to the same RGBA pixels, so a lossless file compares against a lossy one. Only the amount of encoder noise differs, and Color tolerance absorbs it.
Is WebP transparency kept in the compare?
Yes. The alpha channel takes part in the compare. A pixel that changes only in opacity is reported, and pixels that are fully transparent on both sides count as equal.
Can I compare an animated WebP?
Only its first frame. The page decodes each file to one still image, so later frames are not read.
Is there a file size limit?
No server limit applies, because nothing is uploaded. The memory of your device sets the practical limit. Above 10 MB for text, 40 MB for images, 100 MB for documents, or 500 MB for archives, the tool warns you that the work can be slow, but it never blocks the file.
Does this tool work offline?
Yes. The browser keeps a copy of the tool after the first visit, so a page you opened before still works without a network. You can also install DiffResolver as an app from the browser menu. Installation stays optional; the site works the same in a normal tab.
Where is my data stored?
Your files are stored nowhere. They stay in the memory of the page and are gone when you close the tab. Only what you save yourself stays in this browser: a snapshot, your tool options, and your theme. To remove it, open Settings and select Clear all local data.