The idea
Most "free online image tools" work the same way: you upload your file, a server processes it, and you download the result. That model made sense fifteen years ago. Today every browser ships a capable image pipeline (the HTML canvas API with JPEG, PNG and WebP encoders built in), so the upload step is pure downside. It costs you time, it costs bandwidth, and it hands a copy of your file to a company you know nothing about.
Every tool on this site runs on your own device. You can verify that claim yourself in about ten seconds: open your browser's developer tools, switch to the Network tab, and process an image. No upload request appears, because none is made. Or load a tool page, turn off your Wi-Fi, and keep working; the tool still functions.
How it actually works
When you select a file, the browser's File API reads it into memory. The image is decoded with createImageBitmap(), which also applies EXIF orientation so photos from phones are not sideways. The pixels are drawn onto an off-screen <canvas>, transformed as needed, and re-encoded with canvas.toBlob(). The resulting Blob is handed to a download link. At no point does the data leave the page.
A few features go further than a straight canvas call. PNG compression uses a median-cut colour quantiser with optional Floyd-Steinberg dithering, written from scratch. The file size reducer binary-searches encoder quality to land under a byte budget. The favicon generator writes a real multi-frame ICO container, and ZIP archives are built with a small PKZIP writer. All of it is plain JavaScript with no third-party libraries.
Limitations and caveats
- PNG "quality" does not exist. No browser exposes a PNG quality setting. Our PNG compressor reduces the colour palette, which is lossy, and says so on the page.
- Background removal is colour keying, not AI. It works on flat, evenly lit backgrounds and fails on complex ones. Real subject segmentation needs a server-side model, which we do not run.
- Animated GIF and WebP are handled as a single frame. Canvas APIs cannot re-encode animation, so we process the first frame and tell you rather than returning a silently broken file.
- Lossless WebP is not available in the browser. Even at quality 100,
canvas.toBlob()produces lossy WebP. - Client-side code is readable. Anyone can view the source of this site. We make no claim to protect or obfuscate it.
What this costs you
Nothing. There is no account, no email capture, no watermark, no daily limit and no premium tier. The site is funded by advertising placed around the tools, never inside the working area and never disguised as a download button. If an ad ever looks like part of a tool, that is a bug; tell us and we will fix it.
Privacy in one sentence
We never receive your images, so there is nothing for us to store, sell, leak or be compelled to hand over. The full detail is in our Privacy Policy, and the analytics and advertising cookies are described in the Cookie Policy.
Browser support
The tools need a browser with HTML5 canvas and the File API: Chrome, Edge, Firefox, Safari 14+, and their mobile equivalents. WebP output works everywhere current; AVIF output is only offered where the browser can encode it, and the option is disabled otherwise. Internet Explorer is not supported.
Get in touch
Bug reports, missing features and corrections are all welcome at support@imageconvertor.si, or through the contact page.