JPG to WebP

What is JPG?

JPG (also written JPEG) is the longest-running standard for photographic images on the web, in print and across every consumer camera. It uses lossy DCT-based compression — visual detail is discarded to shrink the file — but the trade-off is so well tuned that high-quality JPG remains visually indistinguishable from its source for the vast majority of photographs. Files are an order of magnitude smaller than equivalent lossless formats, which is why JPG has dominated photographic delivery for thirty years and continues to.

What is WebP?

WebP is a modern image format developed by Google in 2010, designed to deliver smaller files than JPG or PNG at the same visual quality. It supports both lossy and lossless compression, a full alpha channel for transparency, and short animation sequences in a single file. WebP is now read natively by every major browser released after 2020 — Chrome, Edge, Firefox, Safari and their mobile equivalents. The codec’s efficiency advantage over JPG comes from a more sophisticated prediction model that exploits more types of spatial redundancy in the image.

Why convert JPG to WebP?

Bandwidth and load times are the headline reason. A typical photographic JPG re-encodes to a WebP roughly 25% smaller at the same quality, which over a page with twenty images adds up to a meaningful reduction in transfer size and a meaningful improvement in load speed. Google’s Core Web Vitals include image-size metrics, and many sites have moved to WebP delivery specifically to score better. If you maintain a website or blog, swapping your photographic JPGs for WebPs is one of the cheapest performance wins available.

Storage is the secondary reason. A photo library or asset folder re-encoded to WebP takes substantially less disk and cloud-storage space than the equivalent JPGs. The visual quality is the same; the files are smaller. For backups and archives that will not be edited again, this is pure win.

Modernising an asset library is the third reason. If your CMS or static site generator supports WebP delivery, converting your existing JPGs once gets all the benefits without the per-image hassle.

How to use this JPG to WebP converter

1. Drop your JPG file onto the dropzone, or click to browse.
2. Adjust the WebP quality slider. The default of 80% is a strong balance for web delivery — visually equivalent to JPG at roughly 90%. Drop to 70-75% for the smallest web-ready file with no visible loss on most photos.
3. Click Convert to WebP to encode.
4. Look at the converted preview. The caption shows the WebP’s size and how much smaller (or larger) it is than the JPG — usually substantially smaller.
5. Click Download WebP to save it. The filename swaps .jpg or .jpeg for .webp.

Quality tips for JPG to WebP

WebP’s quality scale is not directly comparable to JPG’s: WebP at 80% is roughly equivalent to JPG at 90% in perceived quality, while taking fewer bytes. So you can comfortably drop the WebP quality lower than you would set a JPG quality.

Because the JPG has already been through one round of lossy compression, the WebP encoder is working from imperfect input. Going below 70% on the WebP will start to expose the combined artefacts of both encoders — soft edges, faint blocking on flat areas. 75-85% is the practical sweet spot for converting JPGs to WebP for the web.

For the cleanest result, start from the highest-quality JPG you have. If the JPG was already saved at 75% quality, the WebP will inherit those artefacts on top of its own.

Privacy

Your JPG stays on your device. The decoder, the canvas redraw and the WebP encoder all run locally inside your browser, and the download is generated client-side without any server involvement. The Network panel in your browser’s DevTools will show zero requests during the conversion. The page works the same way with Wi-Fi disconnected.

Browser compatibility

JPG decoding is universal. WebP encoding through the canvas API is supported in Chrome and Edge since 2014, Firefox since 65 (early 2019), and Safari since 14 (late 2020). All current browsers therefore encode WebP. On very old Safari versions (pre-14, mostly retired by now) the canvas falls back to a different format and the converter shows an error; the fix is to update Safari or use a current Chrome / Edge / Firefox.