About WebPMagic

WebPMagic is a small, independent project. It started as a single tool — a browser-based converter for turning JPEG, PNG, and GIF files into WebP — and grew to include a set of guides on image optimization and web performance. There's no company behind it and no sign-up; the converter is free to use.

Why It Runs in Your Browser

A lot of online image compressors upload your file to a server, convert it there, and send it back. WebPMagic takes a different approach: the conversion happens in your own browser using the HTML5 Canvas API. There are a couple of reasons we built it that way:

• Your files stay local. Nothing is uploaded, so an unreleased product photo or a private screenshot never leaves your device.
• No round trip. You're not waiting to upload a large file and then download the result.

The honest trade-off is that everything depends on your device's memory rather than a server, so very large images can be slow on older hardware, and re-encoding an already-compressed file can occasionally make it bigger. The tool shows you the before-and-after size for every file so you can see the real result rather than take our word for it.

Why WebP and Core Web Vitals

Image weight is one of the most common reasons pages load slowly, and load speed feeds into Google's Core Web Vitals — particularly Largest Contentful Paint (LCP). WebP usually compresses better than JPEG or PNG at the same visual quality, which makes it a practical first step for trimming page weight.

The converter lets you set the output quality and resize the image, so you can decide where to land between file size and fidelity for your specific use.

About the Guides

Alongside the tool we publish guides on image formats, responsive images, lazy loading, caching, and related performance topics. They're written and edited to be clear and accurate for developers; where they mention numbers like compression ratios, those come from documented sources such as Google's WebP comparison study. If you spot something wrong or out of date, the contact page is the fastest way to let us know — corrections are welcome.