Why WebP Is the Default Image Format for the Modern Web
WebP delivers 25-35% smaller files than JPG and PNG with no quality loss. Here's why it should be your default web image format.
If you care about web performance, you should be using WebP. The format, developed by Google and released in 2010, delivers meaningfully smaller files than both JPG and PNG while maintaining equivalent visual quality. Despite this, many sites still serve legacy formats by default. In this article, we'll explain why WebP deserves to be your default and how to make the switch.
The numbers
Independent benchmarks consistently show WebP's advantage:
- WebP vs JPG: 25-35% smaller at equivalent visual quality
- WebP vs PNG: 60-80% smaller for lossless images
- WebP animated vs GIF: 60-80% smaller
For a typical e-commerce site with 50 product images per page, switching from JPG to WebP can cut total page weight by 1-3 MB. That translates directly to faster load times, better Core Web Vitals scores, and higher conversion rates.
Why WebP is smaller
WebP uses VP8 intra-frame compression, originally developed for video. Compared to JPG's decades-old DCT-based compression, VP8 offers:
- Better prediction modes: The encoder can predict pixel values from neighboring blocks, only encoding the difference
- Adaptive quantization: Different regions of the image can use different quantization steps based on visual sensitivity
- More efficient entropy coding: Arithmetic coding squeezes out bytes that JPG's Huffman coding leaves behind
For lossless mode, WebP uses a separate encoding path that's fundamentally different from PNG's deflate-based approach, achieving 60-80% smaller files for things like screenshots and diagrams.
Feature comparison
| Feature | JPG | PNG | WebP |
|---|---|---|---|
| Lossy compression | Yes | No | Yes |
| Lossless compression | No | Yes | Yes |
| Transparency | No | Yes | Yes |
| Animation | No | No | Yes |
| Max color depth | 8-bit | 16-bit | 8-bit |
| Universal browser support | Yes | Yes | Yes (since 2020) |
WebP is the only mainstream format that handles every use case — lossy photos, lossless graphics, transparency, and animation — in a single container. This is why it's the default for tools like Google's image CDN, Squoosh, and most modern CMS systems.
Browser support: a solved problem
As of 2024, every major browser supports WebP:
- Chrome: since version 32 (2013)
- Firefox: since version 65 (2019)
- Safari: since version 14 (2020)
- Edge: since version 18 (2018)
Combined market share for WebP-supporting browsers is now well over 97%. For the remaining 3%, you can serve JPG or PNG fallbacks using the <picture> element:
<picture>
<source srcset="photo.webp" type="image/webp">
<img src="photo.jpg" alt="Description">
</picture>
The browser picks the first format it supports, so modern browsers get WebP and older browsers fall back to JPG.
How to convert existing images
You have several options for converting existing images to WebP:
Command-line tools
Google's cwebp tool is the reference implementation:
cwebp -q 80 photo.jpg -o photo.webp
For batch conversion, wrap it in a shell loop or use a tool like squoosh-cli.
Image CDNs
Cloudflare Images, Cloudinary, Imgix, and Vercel's image optimizer all auto-serve WebP to supporting browsers. This is the lowest-effort option — upload the original, and the CDN handles format negotiation.
Browser-based tools
If you have a handful of images and don't want to install anything, our JPG to WebP tool converts images entirely in your browser using the Canvas API. Your files never leave your device.
When NOT to use WebP
WebP isn't always the right choice. A few cases where you might want to stick with older formats:
- Email signatures: Many email clients (notably Outlook desktop) don't support WebP. Use JPG or PNG.
- Legacy embedded systems: Industrial displays, older e-readers, and some kiosks may only support JPG.
- Documents intended for print: WebP's lossy mode is optimized for screen viewing. For print, use TIFF or high-quality JPG.
- When you need maximum compatibility with editing software: While most modern editors support WebP, some older versions of Photoshop and GIMP don't.
For typical web publishing, none of these apply, and WebP is the right choice.
AVIF: the next frontier
WebP's successor is AVIF, which offers 20-30% better compression than WebP. AVIF support landed in all major browsers by 2023, but the format is still relatively new and encoding is significantly slower. For most sites, WebP remains the practical sweet spot today — switch to AVIF when your tooling supports it well.
The <picture> element supports as many sources as you want, so you can serve AVIF to modern browsers, WebP to slightly older ones, and JPG as the final fallback:
<picture>
<source srcset="photo.avif" type="image/avif">
<source srcset="photo.webp" type="image/webp">
<img src="photo.jpg" alt="Description">
</picture>
The bottom line
If you're not serving WebP by default in 2025, you're leaving performance on the table. The format is universally supported, delivers meaningful size savings, and the migration path from JPG/PNG is straightforward.
Start by auditing your largest images — those are where the savings will be most impactful. Convert them, verify they render correctly across browsers, and then extend to the rest of your library. Your visitors (and your Core Web Vitals scores) will thank you.