WebP vs JPEG vs PNG: Which Image Format Should You Use?

Three formats handle the vast majority of images on the web, and each one makes a different bet. JPEG optimizes for universal compatibility. PNG preserves every pixel. WebP tries to do both while producing smaller files. The right choice depends on what you're publishing, where it's going, and who's viewing it.

What We're Comparing

Five factors matter when choosing an image format for the web:

• File size — smaller files load faster and cost less bandwidth
• Visual quality — whether compression introduces visible artefacts
• Transparency — whether the format supports alpha channels (needed for logos, icons, overlays)
• Browser support — what percentage of real-world browsers can display the format
• Encoding speed — how long it takes to convert or export

Every format compromises on at least one of these. The question is which compromise matters least for your use case.

JPEG: The Universal Default

JPEG has been the web's photo format since the mid-1990s. It uses lossy compression, which discards some data to shrink file sizes. At quality 80-85%, the visual difference from the original is imperceptible to most people.

Strengths:

• Works in every browser, email client, RSS reader, and image viewer ever made
• Encoding and decoding are fast on every device
• Mature tooling — every CMS, CDN, and image editor handles JPEG without plugins

Weaknesses:

• No transparency support. If you need a logo on a coloured background, JPEG can't do it
• Larger files than WebP at equivalent visual quality — typically 25-35% larger
• Lossy only — every re-save degrades quality further

JPEG still makes sense for images delivered outside the browser: email newsletters, PDF embeds, and systems where you can't control what software renders the image.

PNG: Pixel-Perfect but Heavy

PNG uses lossless compression. Every pixel in the output matches the original exactly. It also supports full alpha transparency, making it the standard for logos, icons, and UI elements.

Strengths:

• Lossless — no quality loss regardless of how many times you edit and re-save
• Full transparency support with 8-bit alpha channel
• Universal browser support, same as JPEG

Weaknesses:

• File sizes are dramatically larger for photographic content. A 1200px photo saved as PNG can weigh 2-4 MB; the same image as WebP at quality 80 is 150-300 KB
• Not suitable for photographs in production — the bandwidth cost is too high
• No lossy mode, so you can't trade quality for size when you want to

Use PNG when the image has transparency and must work in legacy contexts, or when pixel-perfect reproduction matters more than file size (screenshots with text, diagrams with fine lines).

WebP: The Modern Default

Google released WebP in 2010, but adoption was slow until Safari added support in 2020. As of early 2025, Can I Use reports 97%+ global browser support. The holdouts are Internet Explorer (dead) and very old Safari versions that represent under 1% of traffic for most sites.

WebP supports both lossy and lossless compression, plus transparency. In lossy mode at quality 80, it produces files 25-35% smaller than JPEG with no visible difference. In lossless mode, it beats PNG by 20-30% on average.

Strengths:

• Smaller files than both JPEG and PNG at equivalent quality
• Supports transparency (unlike JPEG) without the file size penalty of PNG
• Both lossy and lossless modes in one format

Weaknesses:

• Some email clients still don't render WebP — Outlook on Windows is a notable holdout
• Legacy tools and workflows may not support it (older versions of Photoshop, some CMS plugins)
• Encoding is slightly slower than JPEG, though this only matters for real-time processing at scale

For anything published on a website — blog posts, product pages, landing pages — WebP is the right default in 2025. For a broader look at compression techniques beyond format selection, see our practical guide to optimizing images for the web.

Head-to-Head: Same Image, Three Formats

Here's what happens when you export the same 1200px-wide photograph at quality 80 in each format:

WebP is 34% smaller than JPEG and 91% smaller than PNG for the same photograph. The visual difference between the JPEG and WebP outputs at quality 80 is undetectable without zooming to 400% and comparing pixel-by-pixel.

For a non-photographic image like a screenshot with text, the gap narrows between WebP and PNG but WebP still wins:

PNG still has an edge in raw clarity for lossless content, but WebP lossless gets close at a smaller size. And if you're willing to use WebP lossy at quality 90+, the file drops further while keeping text readable.

What About AVIF?

AVIF compresses even further than WebP — roughly 50% smaller than JPEG at equivalent quality according to tests by Netflix's AVIF research. But browser support sits at around 92%, encoding is 5-10x slower than WebP, and tooling support is still catching up. Worth watching, not yet a default choice for most teams.

The Verdict

WebP wins for 90%+ of web images. It's smaller than JPEG, supports transparency like PNG, and works in virtually every modern browser.

Pick PNG when you need guaranteed lossless quality and transparency in contexts where WebP isn't supported (certain legacy CMS integrations, specific design tools).

Pick JPEG when the image leaves the browser — email newsletters, RSS feeds, PDF generation — or when you're working with tools that don't handle WebP.

If you're running a website and publishing images to a CMS, the answer is WebP. The 3% of browsers that don't support it are old enough that their users are accustomed to missing content. The 25-35% file size reduction across every image on your site compounds into measurably faster page loads and lower bandwidth costs.

Start Here

Export your next blog post's hero image in all three formats at quality 80. Compare the file sizes side by side. Open each in your browser at 100% zoom. The WebP file will be noticeably smaller, and you won't be able to tell the difference visually. That's the entire argument for switching, and it takes about 60 seconds to prove it to yourself.