For years, PNG was the undisputed choice for lossless web images — logos, icons, screenshots, anything needing transparency. Then Google introduced WebP, promising significantly smaller file sizes at equivalent quality, with both lossy and lossless modes and full transparency support. The question is no longer whether WebP is technically better — it often is — but when to use it, and when PNG still wins.

What Is WebP?

WebP is an image format developed by Google and released in 2010. It uses a compression algorithm derived from the VP8 video codec and supports:

  • Lossy compression — like JPG, but more efficient. Produces smaller files at comparable visual quality.
  • Lossless compression — like PNG, but Google claims 26% smaller file sizes on average.
  • Transparency (alpha channel) — unlike JPG, WebP supports transparency in both lossy and lossless modes.
  • Animation — WebP can store animated images, similar to GIF but far more efficient.

What Is PNG?

PNG (Portable Network Graphics) was designed in 1996 as a patent-free replacement for GIF. It uses lossless compression and supports full transparency via an alpha channel. PNG has been universally supported across all browsers, devices, and design tools for decades, making it the most compatible format for images that need to look pixel-perfect.

WebP vs PNG: Head-to-Head Comparison

Feature WebP PNG
Lossless compression Yes (~26% smaller than PNG) Yes
Lossy compression Yes (like JPG, but better) No
Transparency Yes (lossy + lossless) Yes
Animation Yes No (APNG is a variant)
Browser support 97%+ of browsers (2025) 100%
Design tool support Good and improving Universal
Email client support Limited Universal
Print / offline use Limited support Universal

File Size: How Much Smaller Is WebP?

In real-world use, WebP lossless images are typically 20–35% smaller than PNG. WebP lossy images are typically 25–40% smaller than JPEG at comparable visual quality. For websites serving many images, this translates into measurably faster load times and lower bandwidth costs.

The difference is most pronounced for photographic images in lossy mode. For simple graphics with few colors (icons, logos), the size difference between WebP lossless and PNG lossless is smaller.

Browser Support in 2025

WebP is now supported by all major browsers: Chrome, Firefox, Safari (since 14), Edge, and Opera. Browser support covers over 97% of global users. The days when WebP required fallback images for Safari are over.

If you're building for a modern audience, WebP is safe to use without fallbacks. The only scenarios where PNG is definitively more compatible are email clients and certain legacy systems.

When to Use WebP

  • Web performance is a priority. Smaller images mean faster page loads and better Core Web Vitals scores — both of which affect SEO and user experience.
  • You need transparent images in a browser context. WebP lossy with transparency is smaller than PNG while maintaining quality.
  • You're serving images through a CDN or modern CMS. Most modern platforms (Cloudflare, Vercel, Next.js, WordPress) auto-convert or serve WebP when the browser supports it.
  • You're replacing GIFs with animations. Animated WebP is dramatically smaller than GIF and supports millions of colors.

When to Stick with PNG

  • Email marketing. Most email clients (Outlook especially) do not support WebP. Always use PNG or JPG for email images.
  • Design files and assets shared with collaborators. Not all design tools (Figma, Photoshop, Illustrator) handle WebP as fluidly as PNG for source files.
  • Print design. Print workflows expect TIFF, PDF, or PNG — not WebP.
  • Maximum compatibility is non-negotiable. If you genuinely cannot predict your audience's browser or device, PNG is the safe choice.
  • Screenshots and screen recordings. PNG remains the most universally accepted format for screenshots shared across tools and operating systems.

How to Convert Between WebP and PNG

File Converter handles both directions:

  • PNG to WebP: Upload a .png file and select WebP as the output. Use lossy mode for photos and transparent images where some compression is acceptable; use lossless for graphics where every pixel must be exact.
  • WebP to PNG: Upload a .webp file and select PNG. Useful when you need to share an image with a tool or person that doesn't support WebP.

The Verdict

For modern web use, WebP is the better default — smaller files, full transparency, animation support, and near-universal browser compatibility. Switch to PNG when you need maximum compatibility (email, print, legacy tools) or when collaborating with workflows that rely on PNG as the source format.

The best strategy: keep PNG as your master/source file for graphics, and serve WebP to web browsers. Most modern CDNs and frameworks do this automatically.

Frequently Asked Questions

Does converting PNG to WebP lose quality?

It depends on the mode. WebP lossless conversion is pixel-perfect — identical to PNG. WebP lossy compression discards some data (like JPG), so a lossy WebP will look slightly different from the source PNG at close inspection, but files are much smaller.

Can I use WebP as a background image in CSS?

Yes. WebP images work in CSS background-image properties in all modern browsers. For older browsers, use the <picture> element with a PNG fallback in HTML, or serve WebP via server-side content negotiation.

Is AVIF better than WebP?

AVIF often achieves even smaller file sizes than WebP at high quality, and is supported in Chrome, Firefox, and Safari. However, browser support (about 90%) and encoding speed are still maturing. File Converter supports AVIF conversion too — worth testing for your use case.