WebP, released by Google in 2010, is the modern web's default image format. It combines the strengths of JPG (efficient lossy compression for photographs), PNG (lossless mode with alpha transparency) and GIF (animation) into a single format that beats all three on file size at equivalent quality.
Browser support is now universal across Chrome, Firefox, Safari (15+), Edge and every modern mobile browser. WebP is the right default for any image-heavy website where you control delivery — the only remaining cases for sticking with JPG or PNG are when files need to leave your domain to email clients, legacy CMSes or platforms that don't yet handle WebP.
WebP's only meaningful trade-off is decode speed: WebP takes roughly 1.5× as long to decode as JPG on the same hardware. For typical web use this is invisible; on extremely image-heavy pages on older mobile devices it can be measurable. AVIF is even smaller but with a larger decode penalty — WebP sits in the sweet spot.
History — introduced 2010
By: Google
Google released WebP in 2010, based on intra-frame compression from the VP8 video codec. Lossless support and alpha transparency were added in 2011. After years of slow adoption (Safari didn't support WebP until version 14 in 2020), browser coverage is now universal among the current versions of every major browser.
How it works
WebP has two encoding modes. Lossy WebP uses VP8-style intra-frame compression: it divides the image into blocks, predicts each block from its neighbours, and stores the prediction residuals. Lossless WebP uses a custom palette + entropy encoder optimised for sharp edges and large areas of solid colour.
Both modes support full 8-bit alpha transparency. Both modes support up to 16384×16384 pixel images. Animated WebP combines the lossy or lossless mode with frame-by-frame delta encoding similar to MP4 — typically 50–80% smaller than equivalent GIF.
Strengths and weaknesses
Strengths
- 25–35% smaller than JPG at equivalent quality for photographic content.
- ~25% smaller than PNG (lossless) for graphics, with identical alpha transparency.
- Supports animation, transparency, lossless and lossy modes in one format.
- Universal support across every current browser (98% global coverage).
- Encoders are fast — encoding WebP at q80 takes roughly the same time as JPG q85.
Weaknesses
- Decode is ~50% slower than JPG. Invisible on typical web pages, measurable on extremely image-heavy pages on older devices.
- Not supported in legacy systems or many email clients (notably Outlook desktop).
- Some image-editing tools have inconsistent WebP support — Adobe Photoshop only added native WebP in 2022.
- Stripping or editing WebP EXIF metadata is less well-supported than JPG.
When to use it
- Any image-heavy website where you control image delivery
- Hero / above-the-fold imagery (significant LCP improvement)
- WordPress sites (5.8+ supports WebP natively in the media library)
- Shopify product imagery (Shopify's CDN auto-serves WebP)
- Replacing animated GIFs on the web
When NOT to use it
- Email marketing — Outlook desktop doesn't render WebP. Stick with JPG / PNG for transactional and marketing email.
- Files shared via download — recipients on legacy systems may not be able to open WebP.
- Pipelines that integrate with image-editing tools or DAMs lacking WebP support.
- Print workflows — print pipelines almost universally expect TIFF / PNG / JPG.
Browser support
Global coverage: 98%
| Browser | Support |
|---|---|
| Chrome | 32+ (2014) |
| Firefox | 65+ (2019) |
| Safari | 14+ (2020) |
| Edge | 18+ (2018) |
| Legacy / notes | Not supported in Internet Explorer. Email clients vary — Apple Mail and Gmail web render WebP; Outlook does not. |
Performance considerations
- WebP saves roughly 25–35% of bytes for photographic content versus JPG, and 25% versus PNG for lossless graphics. On image-heavy pages this translates directly to faster LCP.
- Decode is ~50% slower than JPG but in practice this is invisible — most pages are bottlenecked on download time, not decode time.
- Animated WebP is dramatically smaller than animated GIF — typical 50–80% reduction with better quality.
SEO considerations
- Google has used Core Web Vitals (which weight image weight heavily) as a ranking signal since 2021. Migrating image-heavy sites from JPG to WebP often produces a visible LCP improvement and a corresponding ranking lift.
- Search engines index WebP correctly. Alt text and filename rules apply identically.
- If you can't migrate every image, prioritise above-the-fold imagery — the LCP image has the biggest single impact on perceived speed.
Common mistakes
- Migrating with no JPG / PNG fallback for clients that can't render WebP. Use <picture> with multiple sources for legacy compatibility.
- Saving WebP at quality 100 — no visible benefit over q85 and dramatically larger files.
- Forgetting to update CMS or build pipeline to handle WebP — many older WordPress themes break on WebP uploads.
- Using lossless WebP for photographs — defaults to lossy WebP for photographic content.
Frequently asked questions
- Should I switch from JPG to WebP?
- If you control image delivery on your site, almost certainly yes. WebP saves 25–35% of bytes at equivalent quality with no visible difference at typical viewing sizes. The exception is email and any client-side workflow where you can't guarantee WebP support — those still need JPG.
- Is WebP supported in Safari?
- Yes — since Safari 14 (released September 2020). Older versions of Safari and iOS need a JPG / PNG fallback.
- Does WebP support transparency?
- Yes — full 8-bit alpha transparency, in both lossy and lossless modes. WebP is the only format that combines transparency with lossy compression efficiency.
- Can I use WebP in Outlook email?
- Outlook desktop does not render WebP. For email marketing, stick with JPG or PNG. Apple Mail and Gmail web both render WebP correctly.
- What's the difference between WebP and AVIF?
- AVIF is smaller (typically 20% smaller than WebP at equivalent quality) but slower to decode and slightly less universally supported. WebP is the safe modern default; AVIF is the cutting-edge option where every byte matters and you can serve a WebP fallback.