Browser tool

Image Quality Comparator

Compare an image against a compressed preview and see the size saved — in your browser.

Quality compare · original vs a compressed preview, with size saved.

Use tool

Drop your image here

or click to browse, or press Enter, drag and drop supported

Compression quality

Lower quality = smaller file. This drives the compressed preview you can download.

Max width (px)

The preview is downscaled if it is wider than this. Use a large value to keep full width.

Compressed format

The compressed preview is encoded in this format.

JPG background colour

Used only when the compressed format is JPG.

Set quality and format, then click Process to build the preview.

Choose a file to begin.

File: —
Output: —

Image Quality Comparator compresses your image in your browser and shows it beside the original; the download is the compressed preview and nothing is uploaded.

Result will appear here.

How this tool works

What it does

Shows the original beside a compressed JPG/WebP preview and reports the size saved.

Scope

Original-vs-compressed, not a two-image comparison; the download is the preview.

Transparency

JPG flattens it onto a colour; WebP can preserve it when the source has an alpha channel.

Privacy

Compression and preview happen in your browser; nothing is uploaded.

Image Quality Comparator in your browser

Image Quality Comparator shows your original image next to a compressed preview at a quality and size you choose, so you can judge how much quality is lost for the file-size saving. The downloadable result is that compressed preview, not the untouched original.

Pick a compression quality, an optional maximum width, and JPG or WebP output. The tool encodes the preview, reports the percentage size saved, and shows both versions side by side.

It compares the original against a compressed version of itself rather than two separate images. JPG output flattens transparency onto a background colour, which is disclosed in the result.

How to use Image Quality Comparator

Upload an image into Image Quality Comparator.
Set the compression quality, optional max width and compressed format.
Click Process to build the compressed preview beside the original.
Review the size saved and quality, then download the compressed preview.

Why use Image Quality Comparator

See the trade-off

View the original and a compressed preview side by side at your chosen quality.

Size saved

Reports the percentage smaller the compressed preview is than the original.

Honest output

The download is the compressed preview; the original is untouched.

Format choice

JPG or WebP output, with a JPG background colour for transparency.

Common uses for Image Quality Comparator

Tune compression

Find a quality setting that balances size and visible quality.

Preview savings

See how small an image gets before committing to it.

Web optimisation

Judge JPG vs WebP for a given image at a target width.

Quality review

Spot compression artefacts against the original.

Frequently asked questions

Does Image Quality Comparator compare two separate images?

No. It compares your original against a compressed version of the same image. To compare two different files side by side, use the Compare Images tool instead.

What exactly do I download from Image Quality Comparator?

The compressed preview — the JPG or WebP version produced at your chosen quality and width. Your original file is not modified.

Does Image Quality Comparator report objective metrics like SSIM?

It reports the percentage file-size saving and the before/after dimensions and quality. It does not yet compute SSIM or PSNR scores.

How does Image Quality Comparator handle a transparent PNG?

If the compressed format is JPG, transparency is flattened onto the background colour you choose. WebP can preserve transparency when the source image has an alpha channel.

Is my image uploaded to compare quality?

No. Compression and the side-by-side preview are generated in your browser; nothing is sent to a server.

Related image tools

Tools that pair well with Image Quality Comparator.