Compare Images
Free image diff with no upload. Compare two images pixel by pixel, with adjustable tolerance and the differences grouped into clear regions.
Files never leave your browser.
About Image Diff
Compares two raster images pixel by pixel and groups adjacent differing pixels into clusters. Runs entirely in your browser. Your images never leave the page.
How to use
- Pick a left image (PNG, JPG, WebP) using the file picker or by dropping it onto the left zone.
- Pick the right image. The diff appears as a colour-coded mask over the originals.
- Raise the tolerance slider to ignore small colour shifts, or change connectivity to control how clusters are formed.
What this tool doesn't handle
- Mismatched dimensions are handled by scaling the smaller image (enable auto-scale, fine-tune in the alignment workspace), but resampling can add minor noise. Identically sized exports compare most precisely.
- Pixel-level comparison only; we do not detect semantic differences such as moved or resized elements.
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.
Can I compare two images with different dimensions?
Yes. Enable auto-scale and the smaller image is scaled and aligned over the larger one; you can fine-tune scale and offset in the alignment workspace. Identically sized exports still give the cleanest pixel results.
How do I ignore small color or compression differences?
Raise the Color tolerance slider so near-identical pixels count as equal, which is useful for JPEG artifacts. You can also exclude specific colors entirely with Ignore picked colors.
How are the differences grouped?
Adjacent differing pixels are automatically clustered into groups, so each visual change shows as one region you can inspect, instead of thousands of individual pixels.
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.