Image Comparison Tool: Original vs Compressed

Compression is always a trade-off, and the only reliable judge is your own eyes. The Image Comparison Tool compresses your image and places the original and the result in the same frame, split by a vertical divider. Drag the handle left and right to reveal more of the Before or the After side, and small artefacts become obvious in a way that two separate windows never show.

Underneath the preview you see the numbers that matter: original and new dimensions, both file sizes, the output format, the quality used and a badge with the percentage saved. Because every change re-renders the result within a moment, you can move the quality slider or switch the output between JPG, PNG, WebP and AVIF and watch the difference in both the picture and the file size.

How to use the Image Comparison Tool: Before and After

1. Drop your images onto the upload area, click it to choose files, or paste an image with Ctrl+V. This page accepts JPG, PNG, WebP, GIF and BMP files, many at once and up to 80 MB each.
2. Grab the round handle in the middle of the preview and drag it across the areas where compression shows first: faces and skin, blue sky and other smooth gradients, fine text and sharp edges. Once focused, the divider also moves with the arrow keys.
3. Try two or three quality levels (for example 60, 75 and 85) or open Format to compare JPG with WebP or AVIF at the same setting, then keep the smallest version you cannot tell apart from the original.
4. Check the result with the before/after slider: drag the divider across the preview and read the new dimensions, file size, quality and percentage saved underneath. Any change to the settings re-processes every image automatically.
5. Download a single image, or use Download all (ZIP) for the whole batch. Under More options you can also set a DPI value and a file-name pattern with {name}, {w} and {h}.

What to look for when comparing

• Banding in gradients. Skies and studio backdrops show visible steps first when JPG or WebP quality is too low, or when a PNG palette has too few colours.
• Blocking and ringing. Around text, logos and high-contrast edges, low quality causes square blocks and faint halos; screenshots usually need a higher setting or PNG.
• Transparency. The preview sits on a checkerboard, so you can see immediately whether transparent areas survived or were filled with a background colour.

If the badge shows "+%", the new file is larger than the original, which is a clear sign to keep the original or to pick a lower quality.

Private, free and fast

The whole job runs in your browser: images are decoded, resized and re-encoded on your own device, so nothing is uploaded to a server. There is no sign-up, no watermark and no daily limit, and location and camera data (EXIF) are removed from every result.