What Is WebP? The Complete Guide to WebP Images
WebP is a modern image format developed by Google that produces significantly smaller files than JPEG and PNG — with no visible quality difference. This guide explains what WebP is, how it compares to other formats, browser support, and how to use it.
What Is WebP?
WebP (pronounced "weppy") is an image format developed by Google and released in 2010. It was designed specifically to reduce image file sizes on the web without sacrificing visual quality. WebP uses advanced compression techniques derived from the VP8 video codec to achieve smaller file sizes than older formats like JPEG and PNG.
Unlike JPEG (designed in 1992) and PNG (1996), WebP was built with modern web performance in mind. It supports both lossy and lossless compression, transparency (alpha channel), and animation — capabilities that JPEG, PNG, and GIF each handle separately. WebP combines the best features of all three.
WebP at a glance
WebP vs JPEG: How Do They Compare?
JPEG has been the standard format for photographs since 1992. It uses discrete cosine transform (DCT) compression, which was state-of-the-art for its time. WebP improves on JPEG's compression algorithm using techniques from VP8 video encoding, including better block prediction and more efficient entropy coding.
The practical result: a WebP image at the same visual quality as a JPEG is typically 25–35% smaller. For a website that serves 1,000 photographs per day, switching from JPEG to WebP reduces bandwidth consumption by 25–35% — directly improving page load speed and Google's Core Web Vitals scores.
| Feature | JPEG | WebP |
|---|---|---|
| Lossy compression | Yes | Yes — 25–35% smaller at same quality |
| Lossless compression | No | Yes |
| Transparency | No | Yes (both modes) |
| Animation | No | Yes |
| File size (photos) | Baseline | 25–35% smaller |
| Browser support | Universal | All major browsers (since 2021) |
| Desktop software support | Universal | Improving — some older apps still lack support |
| Email client support | Universal | Limited — some clients do not display WebP |
When to prefer JPEG over WebP: When sharing with desktop applications that may not support WebP (older Photoshop versions, some Windows apps), or when attaching to emails where client support is uncertain. For all web-delivered images, WebP is the better choice.
WebP vs PNG: When Does WebP Win?
PNG is the standard for lossless images with transparency — logos, icons, screenshots, and graphics. WebP lossless directly competes with PNG and typically produces files 20–30% smaller at the same pixel-perfect quality.
For photographs saved as PNG (which many users do accidentally), the difference is dramatic. A 4MB PNG photograph often becomes a 500KB WebP lossy image — a 87% reduction — while looking identical on screen. WebP's lossy mode handles photographic content far more efficiently than PNG's lossless algorithm.
Use WebP lossless instead of PNG when:
- The image will be served on a website (browser support is universal)
- File size matters and the extra 20–30% savings is worth it
- The image has transparency that must be preserved exactly
Keep PNG when:
- Sharing with users who may open the file in older desktop software
- The workflow requires universal compatibility (print, legacy apps)
- The file size difference is not significant (small icons, small graphics)
WebP Browser Support in 2026
WebP is supported by all modern browsers with a combined market share of over 97%. Safari added WebP support in version 14 (September 2020), closing the last major gap in browser compatibility. In 2026, WebP support can be treated as universal for web use.
Where WebP is not supported: Some email clients (Outlook on Windows, some mobile email apps) do not render WebP images inline. If you are embedding images in email newsletters or attachments, JPEG remains the safer choice. For all other uses, WebP works.
How to Convert Images to WebP
The easiest way to convert existing JPEG or PNG images to WebP is using a browser-based converter that requires no software installation. CompressImg provides free converters for all common source formats:
JPG to WebP →
Convert JPEG photos to WebP for 25–35% smaller files
PNG to WebP →
Convert PNG graphics to WebP lossless
All conversions happen directly in your browser. No files are uploaded to any server — the conversion runs using the HTML5 Canvas API in a Web Worker.
How to Convert WebP Back to JPEG or PNG
Converting a WebP file back to JPEG or PNG is straightforward. You might need to do this when sharing images with people using software that does not support WebP, or when a form or service requires JPEG input.
WebP to JPG →
Convert WebP to JPEG for maximum compatibility
WebP to PNG →
Convert WebP to PNG with transparency preserved
Note: Converting from WebP back to JPEG or PNG will increase file size, since JPEG and PNG are less efficient formats. If the goal is to reduce file size, keep the WebP version and only convert for compatibility when needed.
Frequently Asked Questions
Is WebP better than JPEG?
For web images, yes. WebP produces files 25–35% smaller than JPEG at equivalent visual quality. It also supports transparency and lossless compression, which JPEG does not. The only reason to choose JPEG over WebP is compatibility — some older desktop software and email clients do not support WebP.
Can you open WebP files on Windows or Mac?
Yes. Windows 10 and later can open WebP files natively in Photos. macOS supports WebP in Preview and Safari. For older systems, free software like IrfanView (Windows) or GIMP (cross-platform) opens WebP files. Adobe Photoshop supports WebP since 2021.
Does WebP support transparency?
Yes — WebP supports both lossy and lossless compression with full alpha channel (transparency) support. This makes WebP suitable as a replacement for both JPEG (lossy photos) and PNG (lossless graphics with transparency).
Is WebP good for SEO?
Yes. Google recommends serving images in modern formats like WebP as part of Core Web Vitals optimization. Smaller images load faster, improving Largest Contentful Paint (LCP) scores — a direct ranking factor in Google's algorithm. Switching from JPEG to WebP is one of the most impactful performance improvements for image-heavy websites.
Why don't all websites use WebP?
Most modern websites do use WebP — especially those using content delivery networks (CDNs) that automatically convert images. Older sites that pre-date widespread browser support may still serve JPEG by default. CMS platforms like WordPress now support WebP natively.
What is the difference between WebP lossy and WebP lossless?
WebP lossy (like JPEG) discards image data to achieve smaller file sizes — typically 25–35% smaller than JPEG at the same visual quality. WebP lossless (like PNG) preserves every pixel exactly — typically 20–30% smaller than PNG. Use lossy for photographs and content where imperceptible quality loss is acceptable; use lossless for graphics, icons, and screenshots where pixel-perfect accuracy matters.
Summary
- WebP is a modern image format from Google — smaller files, same visual quality
- 25–35% smaller than JPEG at the same quality setting for photographs
- 20–30% smaller than PNG for lossless graphics with transparency
- Supported by all major browsers (Chrome, Firefox, Safari, Edge) since 2021
- Not recommended for email attachments — use JPEG for email compatibility
- Convert any JPEG or PNG to WebP free at CompressImg — no upload required