WebP vs PNG: Which Format Should You Use?
August 7, 2026· 3 min read
WebP is the format every web developer whispers about, and PNG is the format everyone already trusts. Both support transparency, both are lossless-capable, and both get used for completely different reasons. Here's how to pick — and how to convert between them when you need both.
What is WebP?
WebP is Google's image format, designed specifically for the web. It combines:
- Excellent compression — typically 25–35% smaller than JPEG and PNG at the same visual quality
- Lossy and lossless modes in a single format
- Transparency (like PNG)
- Animation (like GIF, but far smaller)
Every major browser has supported WebP since around 2020, so it's safe to use for website images today.
What is PNG?
PNG is a lossless raster format that has been a web staple since the 1990s. It's the default choice for screenshots, graphics with text, and anything requiring pixel-perfect transparency. Its weakness is file size: PNG files are large compared to modern formats.
WebP vs PNG: side by side
| WebP | PNG | |
|---|---|---|
| File size | Much smaller | Larger |
| Lossless mode | Yes | Yes |
| Transparency | Yes | Yes |
| Animation | Yes | No |
| Photo quality at same size | Better | Good |
| Browser support | All modern browsers | Universal |
| Tool support | Good, improving | Universal |
| Best for | Web images, photos, animations | Screenshots, UI graphics, printing |
When to use WebP
Choose WebP for anything that lives on the web:
- Website photos and product images
- Blog post illustrations
- Animated images (replace GIFs)
- Images where every kilobyte counts (page speed, Core Web Vitals)
When to use PNG
Choose PNG when compatibility or precision matters more than size:
- Screenshots with sharp text
- UI mockups and design deliverables
- Images going into documents or presentations
- Files that will be edited later (lossless round-trips)
- Older software, email clients, or printing workflows that don't understand WebP
How to convert between them
The Image Converter on SlimImg converts between JPG, PNG, and WebP in your browser — no uploads, no accounts.
- Open the converter
- Drop in your images (batch is supported)
- Choose WebP or PNG as the output
- Download the converted files
Converting WebP to PNG is lossless in both directions — the pixels are preserved, only the container changes. Converting PNG to WebP lossy is where the size savings come from.
Choosing the right conversion settings
- PNG → WebP lossy: quality 75–80 looks identical to the PNG for photos and cuts size dramatically
- PNG → WebP lossless: use for graphics with text or sharp edges — smaller than PNG, still lossless
- WebP → PNG: always lossless; no settings needed
If you're not sure which direction makes sense, read the PNG to JPG and WebP to JPG guides too.
Frequently asked questions
Does WebP support transparency?
Yes. WebP supports full alpha transparency, exactly like PNG, in both lossy and lossless modes.
Is WebP smaller than PNG?
Almost always. For the same image, WebP lossless is typically 20–50% smaller than PNG, and WebP lossy is dramatically smaller.
Can I use WebP for print?
No — print workflows expect PNG, TIFF, or PDF. Convert WebP to PNG first using the Image Converter.
Should I replace all my PNGs with WebP?
On websites, yes — if the platform supports it. For files you share with other people, PNG is still the safer default. When in doubt, keep a PNG master and serve WebP copies on the web.
Does converting between WebP and PNG lose quality?
No — both formats support lossless conversion between each other. The pixels survive the round trip; only the container changes.
For a full comparison of every common format, see the image formats guide.
The bottom line
WebP for the web, PNG for everything else — and the Image Converter makes switching between them instant, free, and private.
Try the Image Converter
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