PNG vs WebP: which image format should you use?
Written for web designers, developers and everyday users deciding whether to keep an image as PNG or convert it to WebP
Short answer
Both PNG and WebP support full 8-bit alpha channel transparency, so neither forces you onto a solid white box like JPEG does. The difference is file size vs universal legacy compatibility: according to Google’s published benchmarks, lossless WebP is 26% smaller than PNG on average, and lossy WebP with transparency is 60% to 75% smaller than PNG. Use WebP for websites, web apps and chat stickers where fast loading matters; use PNG for print layouts, lossless design masters and upload portals that reject .webp files.
On this page
For twenty years, whenever an image needed a transparent background or razor-sharp UI text, PNG (Portable Network Graphics) was the only practical choice. JPEG could shrink photographs, but JPEG had no transparency channel and added fuzzy mosquito noise around letters and icons.
WebP changed that trade-off by supporting both lossless compression and lossy compression alongside a full 8-bit transparent alpha channel. Here is how the two formats compare in real numbers and when each one is the right tool for the job.
PNG vs WebP: the measured numbers
| Feature | PNG (.png) | WebP (.webp) |
|---|---|---|
| Lossless compression | Yes (DEFLATE) | Yes (VP8L, averages 26% smaller than PNG) |
| Lossy compression | No (unless quantised to 256-colour PNG-8) | Yes (VP8, 25%–34% smaller than JPEG) |
| Lossy RGB + Transparent Alpha | No | Yes (often 60%–75% smaller than 32-bit PNG) |
| Bit depth | 1, 2, 4, 8 or 16 bits per channel | 8 bits per channel (24-bit RGB / 32-bit RGBA) |
| Maximum pixel dimensions | Unlimited in spec (over 2 billion px) | 16,383 × 16,383 px (VP8/VP8L hardware limit) |
| Browser support | 100% of browsers since 1998 | 97%+ of active browsers (Chrome, Safari iOS 14+/macOS 11+, Firefox, Edge) |
| Legacy desktop / portal support | Universal (every print shop, CMS and government portal) | Still rejected by some legacy upload forms and older office suites |
Where WebP wins decisively
Choose PNG to WebP whenever the image is going to be served over the internet to browsers or mobile apps:
- Transparent e-commerce cutouts and hero illustrations: a 1.4 MB transparent PNG product photo typically drops to 180 KB–260 KB as a quality-85 WebP while keeping smooth transparent drop shadows.
- Documentation and blog screenshots: saving retina screenshots as quality-90 or lossless WebP cuts page weight by a third to a half, directly improving Largest Contentful Paint (LCP) on mobile connections.
- Stickers and chat assets: messaging platforms like WhatsApp, Signal and Telegram standardise on WebP for transparent stickers because of its compact byte size.
Where PNG is still the right choice
Keep PNG (or convert WebP to PNG) in four situations:
- Upload forms that reject
.webp: job portals, government visa forms, trademark registries and some older newsletter tools still validate for.pngor.jpgonly. - Master files you plan to edit repeatedly: if you are passing a graphic back and forth between Figma, Photoshop, Pixelmator or Affinity, keep a lossless PNG master so you never stack lossy compression passes.
- 16-bit photography or images wider than 16,383 pixels: the WebP format specification caps canvas dimensions at
16,383 × 16,383pixels and 8 bits per channel, whereas PNG supports 16-bit-per-channel colour and huge stitched panoramas. - Print production: commercial print workflows expect lossless PNG, TIFF or vector PDF/SVG rather than WebP.
How to switch between PNG and WebP locally
You can batch-convert in either direction inside your browser tab with zero server uploads:
- To shrink heavy PNGs for a website, open the PNG to WebP converter, drop one or more PNG files in, set quality to 85 for photos/cutouts or 100 for small UI text, and download each WebP file.
- To open or upload a WebP image in an older tool that demands PNG, open the WebP to PNG converter, drop your WebP files in, and download the lossless 32-bit PNG copies.
- Notice that both tools write a fresh image container from your browser canvas, automatically stripping any hidden EXIF, XMP or AI generator text chunks from the output.
Questions
Is WebP better quality than PNG?
No format has higher pixel accuracy than lossless PNG, because PNG never discards a single colour or alpha value. Lossless WebP matches PNG’s exact pixel quality at a ~26% smaller file size, while lossy WebP trades a tiny amount of high-frequency detail for a 60% to 75% smaller file.
Does WebP support transparent backgrounds like PNG?
Yes. Both lossless WebP and lossy WebP support a full 8-bit (256-level) alpha channel, including smooth semi-transparent drop shadows and feathered cutout edges.
Why is my PNG file so much bigger than the WebP version?
PNG uses general-purpose DEFLATE compression (LZ77 + Huffman coding) designed in the 1990s. WebP uses modern spatial block prediction, adaptive colour-transform filters and arithmetic/entropy coding that pack photographic and gradient areas far more tightly.
When should I keep PNG instead of converting to WebP?
Keep PNG when sending logos or screenshots to a print shop, archiving master design assets you plan to re-edit many times, working with 16-bit-per-channel colour, or uploading to a government or HR portal that only accepts .png and .jpg.
Does converting PNG to WebP or WebP to PNG in your browser upload my files?
No. Both converters decode and encode the files inside your browser tab on your own device, and strip any embedded EXIF, XMP or PNG text metadata in the process.
Keep reading
What is a WebP file and how do you open or convert it?
Why saved web images end in .webp, how WebP compares with JPG and PNG, and how to convert WebP without uploading your file.
GuideHow to compress images for email (and why 25 MB is really 18 MB)
Base64 email encoding inflates photo attachments by 33%. Here are the real Gmail and Outlook limits and how to shrink photos to fit.
GuideProfile picture sizes: exact pixels and safe crop zones
One 800 x 800 or 1080 x 1080 square fits almost every platform, provided your face sits inside the circular crop mask.
