Image format converter and compressor
Nothing is uploaded — the file is processed entirely in your browser.
Convert between JPEG, PNG and WebP, and compress with a quality slider.
How it works
Converts an image between JPEG, PNG and WebP, with a quality control for the lossy formats and a live file-size readout.
The formats are not interchangeable and choosing wrongly is the usual cause of a needlessly large file. JPEG is lossy and has no transparency; it suits photographs and is terrible for text, line art and screenshots, where it produces visible ringing around edges. PNG is lossless with full transparency and suits exactly what JPEG is bad at, while being far larger for photographs. WebP does both jobs and is typically 25 to 35% smaller than an equivalent JPEG.
Converting a JPEG to PNG does not recover quality. The compression artefacts are already baked into the pixels, and PNG will faithfully preserve every one of them in a much larger file. Conversion only ever goes downhill.
Quality 80 to 85 is the usual sweet spot for JPEG — above that the file grows quickly for differences most people cannot see, and below about 70 the artefacts become obvious in flat areas like skies.
This tool runs entirely in your browser. Nothing you enter is sent to a server, logged or stored, and the page keeps working with the network disconnected.
Common questions
- Which image format should I use?
- JPEG or WebP for photographs, PNG or WebP for screenshots, text and anything needing transparency. WebP is usually 25–35% smaller than JPEG at the same quality.
- Does converting JPEG to PNG improve quality?
- No. The artefacts are already in the pixels. PNG will preserve them perfectly in a much bigger file.
- What JPEG quality should I use?
- Around 80–85. Above that the file grows fast for invisible gains; below 70 the artefacts show in skies and flat areas.
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Sources
- Calculated on this page — At One Place