PNG vs JPEG vs WebP: Which Format When

Updated July 26, 2026

Three formats cover nearly every image on the web, and picking the wrong one costs you either quality or kilobytes — a photo saved as PNG can be ten times larger than it needs to be, and a logo saved as JPEG grows fuzzy halos around every edge. The decision is simpler than the format wars suggest. Here is the comparison, then the rules of thumb.

The three formats at a glance

What lossy vs lossless means for your eyes

PNG compresses like a ZIP file: every pixel comes back exactly as it went in, which is why text stays razor sharp and flat colors stay flat. JPEG instead throws information away — it keeps the broad strokes and discards fine detail human vision is bad at noticing. In a photograph, that trick is nearly invisible and saves enormous amounts of space. On a screenshot it backfires: sharp edges between text and background are exactly what JPEG’s math handles worst, producing the smudgy “mosquito noise” around letters that marks a screenshot saved in the wrong format. WebP plays both games — its lossy mode beats JPEG by roughly 25–30% at similar quality, and it adds the transparency and animation JPEG never had.

File-size intuition: one photo, three ways

Take a 1920×1080 photograph. Uncompressed, that’s about 6 MB of raw pixels. Saved as PNG it might land around 3 MB — lossless can only squeeze a photo so far. As a quality-85 JPEG it drops to roughly 300 KB, and as lossy WebP to perhaps 220 KB — a 90%+ saving over the PNG with no visible difference at normal viewing size. Now reverse the content: a screenshot of a settings dialog might be 60 KB as PNG and larger — and visibly worse — as JPEG. The content decides the format; you can see this yourself by dropping one image into the Image Compressor and comparing outputs side by side.

Rules of thumb

• Photographs → JPEG or WebP. Never PNG unless you’re editing and need a lossless master.
• Screenshots, UI captures, diagrams, logos → PNG. Crisp edges and flat color are lossless territory. (For logos and icons, honestly, SVG beats all three when you have a vector source — it scales forever and stays tiny.)
• Anything needing transparency → PNG or WebP. JPEG has no alpha channel at all — convert a transparent PNG to JPEG and the background comes back solid white, usually discovered only after the logo lands on a dark page.
• Web delivery → WebP by default. Smallest files, transparency, animation, universal in current browsers.

The WebP caveat

WebP’s weakness isn’t browsers — it’s everything else. Email clients (Outlook notably), older versions of Office and Photoshop, some CMS uploaders, government portals and print workflows still reject or mishandle it. And the person you send a .webp to may simply not know what to do with it. The pragmatic split: WebP for images your website serves, JPEG/PNG for images you hand to other people. When a site hands you a .webp you need as something else — or the reverse — the Image Converter switches between all three formats right in the browser: your image is never uploaded anywhere, and the conversion takes a second or two even for large files.

What about AVIF and the rest?

AVIF compresses even harder than WebP and is now supported by all major browsers, but encoding is slow and tooling support outside the web is thinner still — it’s a great additional format for high-traffic sites, not yet a replacement for knowing the big three. GIF survives purely as a meme-delivery mechanism; animated WebP does the same job at a fraction of the size.

The one-sentence version

Photos get JPEG (or WebP), graphics get PNG (or SVG), websites serve WebP, and when the file you have doesn’t match the format you need, converting takes ten seconds. If size still matters after choosing well, compressing and resizing matter more than the format itself — our guide to compressing images for the web covers that workflow.