Private Squoosh-derived image codec

JPEG vs WebP Size Comparison

Encode the same local pixels as MozJPEG and WebP at one selected quality for an honest side-by-side size and visual comparison.

Free to use Your source image and encoded result stay in temporary browser memory and are never uploaded to Lucaden.

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How it works

Complete the job in three clear steps

Choose one JPG, PNG, or WebP image from this device.
Adjust the available codec settings and create matched MozJPEG and WebP candidates with MozJPEG and libwebp via jSquash.
Compare the dimensions and file sizes, inspect the full result, then download it.

Important

Check the result before relying on it

Keep an untouched copy of important source files. Browser processing depends on available device memory, and you should inspect every downloaded result before deleting the original.

Practical details

What this Lucaden tool does

Encode the same local pixels as MozJPEG and WebP at one selected quality for an honest side-by-side size and visual comparison.

The same numeric quality is not a perceptually identical setting across codecs. Treat the result as a practical comparison and inspect both candidates at full size.

Lucaden adds a focused workflow, conservative memory limits, honest size reporting, local previews, and exact dependency attribution.

Included capabilities

Two real WebAssembly encoders
Matched quality input
Side-by-side previews
Exact byte and savings reports

Useful for

Choose a website image format
Compare codec weight
Review visual artifacts
Plan a migration from JPEG

Questions

About this tool

Does Lucaden upload the image?

No. Browser APIs decode the selected pixels and the pinned jSquash WebAssembly codec runs locally.

What should I verify?

The same numeric quality is not a perceptually identical setting across codecs. Treat the result as a practical comparison and inspect both candidates at full size.

Which open-source engine is used?

MozJPEG and libwebp via jSquash is provided through a version-pinned jSquash package derived from the Squoosh codec work. jSquash remains Apache-2.0 and retains its upstream attribution.

Open-source foundations

Built transparently

Lucaden documents its standards sources, architectural references, and permissive runtime dependencies while keeping this workspace consistent with the Lucaden interface.

jSquashApache-2.0 source Third-party noticesLicenses and attribution