Choose an image
Image content matters, so every estimate starts from your actual decoded pixels.
JPG · PNG · WEBP ESTIMATES
Estimate image size before export
Estimate JPG, PNG and WebP export sizes from real browser-encoded samples across quality and target dimensions, with honest uncertainty ranges.
Estimate export file sizes
Real local samplesHOW IT WORKS
A private browser workflow
Your files stay in this tab and are not sent to an image-processing server.
Set output dimensions
Compare target width and height up to 10,000 pixels.
Encode real samples
The browser encodes JPG, PNG and WebP samples at the chosen lossy quality.
Read honest ranges
Projected sizes are labeled estimates and include a likely variation range.
Common questions
Are these exact output sizes?
No. They are estimates based on real samples; encoder, metadata and image-detail differences affect final bytes.
Why does PNG ignore quality?
PNG is lossless, so the lossy quality control applies only to JPG and WebP.
Are images uploaded?
No. Sample encoding and estimation happen locally.