PNG vs WEBP: Which Image Format Should You Use?

PNG and WEBP both support transparency and lossless compression, so a lot of people treat them as interchangeable. They are not. PNG was designed in 1996 to be a lossless, patent-free replacement for GIF. WEBP arrived in 2010 from Google with a different goal: smaller files for the web, in both lossy and lossless modes. The right choice depends on what you are doing with the image, not which format is newer.

What PNG is best for

PNG shines whenever you need crisp, lossless results and broad compatibility. It is the safe default for logos, icons, screenshots, charts, line art, and any image that will be edited and re-saved many times. Because PNG is lossless, you do not lose quality each time you save, which matters for design files passed between people.

It also has the widest support footprint of any modern format. Every browser, every operating system, every printer driver, and almost every piece of imaging software has supported PNG for over twenty years. If you are sharing a file with someone whose setup you cannot predict — a client, a print shop, an older internal tool — PNG is unlikely to embarrass you.

What WEBP is best for

WEBP is built for the modern web. It produces smaller files than PNG and JPG at the same visual quality, supports transparency like PNG, and supports both lossy and lossless modes. For hero images, blog photography, product shots, thumbnails, and UI screenshots that ship to a browser, WEBP almost always wins on file size.

If your priority is faster pages, better Largest Contentful Paint scores, and lower bandwidth bills, WEBP is the format you should be serving. Modern static site generators, image CDNs, and the Next.js / TanStack Start image components all produce WEBP automatically because of how consistent the savings are.

Size comparison

These numbers vary by image, but the pattern holds: lossless WEBP is roughly 25–35% smaller than PNG, and lossy WEBP is dramatically smaller again when you can tolerate some compression. For photography, the difference is enormous.

Transparency

Both formats support full 8-bit alpha transparency. There is no quality difference for transparent edges or drop shadows between PNG and lossless WEBP. The only thing that changes is file size — WEBP gets you the same crisp transparent edges for less.

Image quality

Lossless PNG and lossless WEBP are pixel-identical. Lossy WEBP is a different story: at quality 75–85 it is visually indistinguishable from the original for the vast majority of photos. Go below 60 and you start to see banding in skies and softness in fine detail, similar to a low-quality JPG.

Website speed and Core Web Vitals

Image bytes are usually the largest cost on a content page. Replacing PNG photos with lossy WEBP often shaves 60–80% off image weight, which moves Largest Contentful Paint times directly. If you care about SEO performance scores or mobile users on slower networks, this single change is one of the highest-impact things you can do.

Social media use

Be careful here. Most social networks ingest your image, recompress it themselves, and serve their own format back. Some platforms still do not accept WEBP uploads at all. For now, the safer choice for social posts and email attachments is JPG (for photos) or PNG (for transparent graphics).

When not to use WEBP

• When your recipient runs very old software that pre-dates 2020.
• When you need to paste the image into a Word document, Outlook email, or a tool that does not accept WEBP.
• When the file will be re-edited many times — lossy WEBP degrades on each save.
• When uploading to a platform that quietly rejects WEBP and silently fails.

When PNG is still better

• Editable design assets where lossless quality must survive many saves.
• Tiny UI icons where compression savings are negligible anyway.
• Images going into systems with strict format requirements.
• Anything that needs to print reliably at high resolution.

Quick rules of thumb

• Photos on a website you control: WEBP, with JPG fallback.
• Logos and icons on a website: PNG or SVG, switch to WEBP if many are loaded.
• Source files you keep editing: PNG.
• Files going to social media or email: JPG for photos, PNG for graphics.