Batch JPG to WebP converter

Use cases

• Create modern web-delivery copies of catalog photography
• Normalize several JPEG files to one WebP workflow
• Test whether a specific image batch benefits from WebP

Numeric quality values are not cross-format scores

JPEG quality 82 and WebP quality 82 are encoder controls, not equivalent visual-quality grades. The two encoders use different models and can produce different artifacts, file sizes and edge behavior.

Compare the actual files at the dimensions where customers will see them. Do not judge only from the percentage shown in a control.

Generation loss still applies

A JPEG has already discarded information. Decoding it and encoding WebP introduces another lossy generation unless the output mode is lossless. Fine text, fabric patterns and sharp product edges deserve special review.

• Convert from an original PNG or camera master when available.
• Avoid repeatedly converting between JPEG and WebP.
• Retain the source JPEG for rollback and marketplace compatibility.

The benchmark includes a WebP result that is larger

For the deterministic 1600×1200 opaque fixture, the quality-95 JPEG source was 578,616 bytes, JPEG quality 82 was 235,822 bytes, and WebP quality 82 was 323,606 bytes. That single fixture does not rank formats; it demonstrates why output must be measured.

How local browser processing works

The browser decodes each JPEG, applies EXIF orientation, runs optional resize and watermark steps, then encodes WebP in a local worker. Only the site code and codec assets use the network; selected JPEG bytes and generated WebP results remain local.

Selected images, filenames and watermark text are not sent to a BatchMint processing server. The browser still requests the site code, styles and codec assets used on demand.

How to use it

1. Choose JPEG files and select WebP output.
2. Set maximum width or target size only when the destination requires it.
3. Process locally, compare visual details and retain the original JPEG files.

Sources and verification dates

Platform rules can change. Marketplace requirements below link to official pages, with the retrieval date and scope recorded for each source.

• BatchMint JPEG and WebP benchmark

  Downloadable deterministic files and measured byte counts.

• BatchMint format comparison

  Compatibility and use-case comparison for JPEG, PNG, WebP and AVIF.

Limitations

• WebP output cannot restore JPEG source detail.
• Metadata is not guaranteed to be retained.
• Some publishing tools still prefer JPEG even when browsers support WebP.

FAQ