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Image Compare

Check how two images differ with a slider, blink or difference view, plus numbers for differing pixels, PSNR, SSIM and file size. The images are compared in your browser and never uploaded.

On-device・No uploadMobile friendlyWorks offline

Your files and input are processed only inside your browser on this device and are never uploaded to our servers.

Image A (reference)Not chosen

Image A (reference)

PNG / JPEG / WebP / GIF (first frame) / AVIF (if your browser supports it). Choosing two files at once fills A and B.Accepts: PNG / JPG / JPEG / JFIF / WEBP / GIF / AVIFUp to 100 MB per file
Image BNot chosen

Image B

Accepts: PNG / JPG / JPEG / JFIF / WEBP / GIF / AVIFUp to 100 MB per file
Images are compared in this browser on your device and never uploaded.
Choose two images to see the comparison here.

How to use

  1. A (base).png
    B.png

    Add two images to compare

  2. diff.pngWith PSNR and SSIM

    Show differences in color, with numbers

Compare two images: overlay them to show the differences and the numbers

  1. Choose images for “Image A (reference)” and “Image B” (choosing two files at once fills both). “Try a sample” works too.

  2. If the sizes differ, pick “Resize to match”, “Align top-left” or “Align center”.

  3. Switch between “Slider”, “Side by side”, “Blink” and “Difference”. Raise the zoom and move over an image to use the magnifier.

  4. In the difference view, adjust the threshold (how small a difference to ignore) and the highlight colour.

  5. Read the differing pixels, PSNR, SSIM and file sizes, and save the difference or side-by-side image as PNG if needed.

What it does

Four ways to look

Side by side (zoom and scroll stay in sync), a slider overlay, blinking between A and B, and a difference view that colours only the pixels that differ.

Adjustable difference strength

Set a threshold (0–254) and a colour so only differences larger than that are highlighted. Raise it to look past small compression noise.

Numbers too

Differing pixel count and share, the largest difference, PSNR, a simplified SSIM, and file size, dimensions and format for both. The method is written on the page.

Different sizes are fine

Resize to the smaller image, or align the top-left corners or the centers. Numbers and pictures use the aligned result.

Magnifier

Moving over an image enlarges that spot in A, B and the difference at once, so you can inspect individual pixels.

Built for big images

The comparison runs in a Web Worker and can be canceled. Up to 40 megapixels per image.

Use cases

  • Check that an image still looks right after compressing or converting it
  • Find what changed between two versions of a design or screenshot
  • Confirm that two files that should be identical really are
  • Compare JPEG, WebP and AVIF quality (compress with “Image Compressor”, or target a file size with “Image Target Size”)
  • Play spot-the-difference with two photos

Supported formats

Input

PNGJPEGWebPGIF (first frame only)AVIF (if your browser supports it)

Export

Difference image PNGSide-by-side image PNG

Capability matrix

FeatureSupportNotes
Side by side, slider, blink and difference viewsSupported—
Differing pixel count and share, largest difference, PSNRSupported—
SSIMPartialSimplified (luma only, average of 8×8 blocks); will not match other tools exactly
File size, dimensions and format comparisonSupported—
Aligning images of different sizesSupportedResize to match / top-left / center
Save the difference and side-by-side images as PNGSupportedDifference at full size; side-by-side at preview size
Comparing as the browser renders themPartialColour spaces and ICC profiles are not handled strictly; images are compared as the browser draws them
Every frame of an animated GIFNot supportedOnly the first frame is compared
Comparing what the pictures mean (AI)Not supportedOnly pixel differences are compared
Video, SVG and HEICNot supportedHEIC opens only in browsers that support it, such as Safari

Limits & notes

  • Up to 100 MB and 40 megapixels per image. If the aligned canvas for images of different sizes would exceed 40 megapixels, they cannot be compared.
  • The on-screen preview is scaled to at most 4096 px on the long edge. The numbers and the exported difference image use the aligned full size.
  • Zoom is relative to the preview image, so for very large images the on-screen magnification does not match the original pixels.
  • Numbers are computed from how this browser draws the images. EXIF orientation is applied, but colour spaces (such as Display P3) and ICC profiles are not handled strictly.
  • Transparent areas are compared as white, but differences in opacity also count as differences.
  • Blinking switches once per second and never starts by itself.
  • Phones and tablets work too, but fine adjustment with the magnifier and difference threshold is more reliable on a PC.

Privacy & safety

Reading, comparing and exporting all happen inside your browser. Images are never sent to or stored on a server.

FAQ

How do I find the difference between two images?
Choose one image for A and one for B, then open “Difference” to see differing pixels highlighted in colour. “Slider” and “Blink” let you flip between them as well.
Can I check whether compression hurt the quality?
Yes. Put the original in A and the compressed file in B, then read PSNR, SSIM and the differing pixels, and check with the slider and magnifier. Compress with “Image Compressor”, or aim for a file size with “Image Target Size”.
How should I read PSNR and SSIM?
For both, higher means more alike. PSNR is a dB value from the pixel error and shows “∞” for identical images. SSIM is closer to 1 when similar; this tool’s is a simplified, luma-only version. Numbers alone do not decide how good something looks, so check the images too.
Can I compare images of different sizes?
Yes. Resize to the smaller one, or align the top-left corners or centers. Areas that exist in only one image count as different.
Are my images uploaded?
No. Everything happens in your browser; images never leave your device.

Image Compressor

Drop images to shrink them in bulk while keeping them sharp. Convert to WebP or AVIF, resize, and compare before and after. Your images are never uploaded.

No upload

Image Target Size

To get an image under 200 KB, 1 MB or another limit, pick the target and add the image. The best-looking JPEG or WebP that fits is found automatically: quality is lowered first, and pixels are reduced only if that is not enough. Nothing is uploaded.

No upload

Image Converter

Choose the target format first, then drop images to convert them in bulk. Tune quality per format, use lossless WebP, set a background for transparency and name the output files — nothing is uploaded.

No upload

Duplicate Similar Images

Load a photo folder and identical images and near-identical photos are grouped, with one image per group recommended to keep and the reason shown. Nothing is uploaded, and your original files are never deleted or changed.

No uploadBeta

EXIF & GPS Remover

Remove the location (GPS), camera details and timestamps embedded in your photos without touching image quality. Inspect what was inside and verify the result — all in your browser.

No upload

Image Metadata Editor

Check the EXIF, IPTC and XMP in your photos and rewrite copyright, author, location and more. Image data is never touched, so quality stays the same, and everything runs in your browser.

No upload

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