WebP vs PNG for Mobile Apps — Which Should You Use?

Both formats do the same basic job — store an image with transparency support — but they land in very different places on file size. If you're still shipping PNG everywhere out of habit, here's what switching actually gets you, and the handful of cases where PNG is still the right call.

The core difference

PNG uses lossless compression — every pixel comes back exactly as it went in, at the cost of a larger file. WebP supports both lossless and lossy modes; in lossy mode (the one most apps should use for photos and complex images), it achieves file sizes roughly 25-35% smaller than PNG at visually equivalent quality, and often 25-30% smaller than JPEG too.

Side-by-side comparison

When PNG is still the right choice

• App icons and launcher icons — these are tiny files already; the size savings from WebP are negligible, and PNG is what every platform's tooling expects by default.
• Screenshots with sharp text or UI elements — flat colors and crisp edges compress very well with PNG's lossless algorithm, sometimes better than lossy WebP at a quality setting high enough to keep text readable.
• Anywhere you need guaranteed pixel-perfect output — design mockups, legal documents rendered as images, or anything where lossy compression artifacts are unacceptable.

When WebP wins clearly

• Photos and complex in-app images — the format's strength is exactly this kind of content.
• Any bundled image contributing meaningfully to your app's download size — see how to reduce app size for the bigger picture.
• Website images — smaller images mean faster page loads and better Core Web Vitals scores.

A simple rule of thumb: if it's a photo, use WebP. If it's an icon or has sharp text, use PNG. If you're not sure, compress both and compare.

How to switch

1. Open the image converter and drop in your PNG files (or JPGs, or a mix).
2. Pick WebP as the target format.
3. Convert the whole batch and download it as one ZIP.

If you want to tune the compression level rather than just convert at default quality, the image compressor gives you a quality slider and a live before/after preview so you can find the smallest file that still looks right.