Image Converter

How Image Converter works

Convert images between JPG, PNG and WebP instantly, with transparency handling and quality control. Everything happens inside this page: the tool reads your input, runs the calculation or conversion locally, and hands the result back to you. Nothing is transmitted, because there is no backend to transmit it to.

That design choice is deliberate. Most free tool sites upload your files to a server, process them there, and quietly keep a copy. Toolcin cannot do that — the site is a set of static files. If your connection dropped the moment the page finished loading, every tool would still work.

What the conversion actually does

The image is drawn onto a canvas at its original pixel dimensions and re-encoded in the format you pick. That is a full re-encode, not a container rename: the pixels are resampled through the browser's decoder and encoder.

Because of that, converting PNG to JPG cannot stay lossless, and converting JPG to PNG cannot recover detail the JPG already discarded. The output is a faithful copy of what you can currently see, nothing more.

Choosing the format

PNG is lossless and keeps transparency, which makes it right for screenshots, logos, icons and anything with sharp edges or flat colour. It is a poor choice for photographs, where it can be several times larger than JPG.

JPG is lossy and small, and it has no transparency — this tool fills transparent areas with white rather than leaving them black. WebP is the modern middle ground: smaller than JPG at the same visible quality, and it supports transparency, which makes it the best default for the web if every target browser supports it.

The quality slider

Quality only affects JPG and WebP, from 40 to 100, and it does nothing to PNG because PNG is lossless. Around 92 is the usual sweet spot for photographs: noticeably smaller than 100 and visually identical on a screen.

Below about 70, flat areas start to show blocking and text edges develop halos. If the output is going to be printed, stay at 92 or above; if it is a thumbnail, 60 is plenty.

Transparency and edge cases

A transparent PNG converted to JPG gets a white background. There is no colour picker for that fill, deliberately: white is what every document and website expects, and a coloured fill chosen by mistake is harder to spot than a white one.

Animated files lose their animation, because only the first frame is drawn to the canvas. If you need the animation preserved, convert to WebP with an encoder that supports animation — this tool does not.

Good to know

• Works offline once loaded, including on flights and in locked-down networks.
• No file size limit beyond your device's own memory.
• Free to use, with no account and no usage counter.
• Results are produced locally, so they are not logged or shared with anyone.

Questions