About this tool
Apply one reproducible resize and encoding policy across a batch, inspect each file result, and retain an export manifest for publishing or QA.
- Validates PNG, JPEG, WebP, GIF, and AVIF signatures, decoded dimensions, 20 MB file limits, and a 30-file or 300 MB batch ceiling.
- Supports contain, cover, and long-edge resizing with bounded target canvases, alpha or solid padding, and explicit upscaling control.
- Processes sequentially with cancellation between files and verifies MIME, signatures, and decoded dimensions for every output.
- Exports collision-safe files plus a reopened ZIP and JSON manifest recording settings, dimensions, formats, and before/after bytes.
How to use Batch Optimizer
Add images, choose dimensions, fit behavior, format, and quality, then compare per-file output before downloading individual files or a ZIP manifest.
When this tool is useful
- Preparing a consistent web image batch.
- Converting mixed source formats for a publishing pipeline.
Practical tips
- Keep originals because re-encoding is lossy.
- Review text-heavy screenshots at 100% zoom.
Examples you can test
Load an example, compare the result with the expected output, then replace it with your own input.
Prepare product images
Example input
12 JPEG and PNG files; 1600 px maximum; WebP quality 82
Expected output
Optimized WebP files plus manifest
Animation and source metadata are not preserved.
Validation checklist
- Inspect output dimensions and format.
- Compare visual quality on detailed images.
- Confirm failed files before downloading the ZIP.