Compare image format file sizes across supported encodings
Compare image format file sizes by encoding the same decoded image in available formats, then download a CSV of the resulting byte sizes. Free to use, with no sign-up required.
Files processed on your deviceImages are decoded and re-encoded in this tab. Nothing is uploaded.
01 How it works
- Choose an image.
- Encode it in the available formats.
- Download the size comparison report.
02 Good to know
The report compares encoded byte sizes for the same decoded image. It does not rank visual quality; inspect each format for your use case.
03Compare image formats by file size
The report records file sizes for the available encodings of one decoded source image. A smaller byte count tells you which candidate is smaller for this input and these settings.
The report does not measure visual quality. Lossy formats can trade detail for size, while PNG may suit images that need lossless output or transparency. Inspect each candidate before choosing a format.
04Treat this as a per-image comparison
Results depend on the image, encoder, browser support, and selected settings. One file cannot establish which format is always smallest or best. Use the CSV to compare candidates for this image, then review their appearance.
05 Questions
Does the report say which format looks best?
No. It compares encoded file sizes, not visual quality.
Can I generalize the result to every image?
No. It describes the available encodings of the selected source image and settings.
What does the tool download?
A CSV report listing available formats and their encoded file sizes.