WebP vs. JPG vs. PNG: Which Image Format Should You Actually Use

Three Formats That Get Chosen Out of Habit

Most people pick between JPG and PNG on autopilot — photos are JPG, everything else is PNG — and never consider WebP at all, even though it's been supported in every major browser for years. That habit isn't wrong exactly, but it leaves real file-size savings on the table, because the actual decision has less to do with habit and more to do with two questions: does the image need transparency, and does it need to be pixel-perfect or just look right?

What Each Format Is Actually Built For

• JPG uses lossy compression tuned for photographs — smooth color gradients and complex detail compress well, at the cost of some quality loss that's usually invisible at normal viewing sizes. It has no transparency support at all.
• PNG uses lossless compression — every pixel is preserved exactly, which makes it the right choice for anything that needs sharp edges (text, logos, icons, screenshots) or an actual transparent background. That losslessness comes at a real size cost: a PNG of a photograph is typically much larger than an equivalent JPG, because lossless compression can't take the same shortcuts.
• WebP was built by Google specifically to beat both at once — it supports both lossy and lossless modes, supports transparency (unlike JPG), and its lossy mode typically produces meaningfully smaller files than JPG at equivalent visual quality, and its lossless mode typically beats PNG the same way.

So Why Isn't Everything WebP Already?

Mostly inertia. WebP has had broad browser support since 2020, but a huge amount of existing web content — CMS themes, old image libraries, stock photo sites, email — was built assuming JPG and PNG and never got updated. There are a few genuine remaining reasons to still reach for the older formats: PNG remains the safer choice when a file needs to work in software that doesn't handle WebP (some older desktop image editors, some print workflows), and JPG remains the more universal choice for a file you're handing off to a system you don't control the compatibility of.

The Practical Rule

For anything you control end-to-end — your own website's images, an app's assets — WebP is usually the better default: smaller files, same or better quality, transparency included. Reach for PNG specifically when you need guaranteed lossless fidelity in a context you know doesn't support WebP. Reach for JPG specifically when you're handing a photo to a system, person, or piece of software where you can't be sure WebP will be understood.

FileCast's WebP to JPG and JPG to WebP tools convert either direction instantly in your browser, and PNG to WebP handles the transparency-preserving case — all with nothing uploaded.

The One-Sentence Version

WebP usually beats both JPG and PNG on file size at equal quality — the older formats still earn their place only when you need guaranteed compatibility with software that doesn't support WebP yet.