PNG vs WebP: which format for the modern web?
PNG is a mature lossless format supported everywhere; WebP is a newer format that offers both lossless and lossy modes plus alpha and animation. WebP often delivers smaller web images, but PNG remains the safest master and universal fallback. The best choice depends on the job.
There is no single winner. Reach for WebP to ship smaller images to modern browsers, keep a lossless PNG (or other lossless master) as your editable source, and provide a fallback where universal compatibility matters. Use the scenario table below to decide.
Lossless and lossy: PNG has one mode, WebP has two
PNG is always lossless. It compresses with filtering followed by DEFLATE and restores the original samples exactly, so it never introduces compression artifacts regardless of how the file is produced.
WebP supports two modes. Lossy WebP is based on VP8 intra-frame coding and trades exactness for smaller files, much like JPEG. Lossless WebP uses a different technique that preserves the original pixels, similar in spirit to PNG.
This means WebP can replace PNG for graphics in its lossless mode and replace JPEG for photos in its lossy mode. Choosing the WebP mode deliberately matters: use lossless for flat graphics you need pixel-exact, and lossy for photographic content where small size wins.
Alpha transparency in both formats
PNG supports a full alpha channel, letting each pixel carry its own opacity for clean edges on any background.
WebP also supports alpha transparency, and it can combine alpha with lossy colour compression — an option PNG does not have. That combination can produce a transparent image that is smaller than an equivalent PNG while keeping soft edges, which is useful for web overlays and icons.
Animation caveats
WebP supports animation, so a single WebP file can hold a short animated sequence with alpha, an alternative to animated GIF or APNG.
There are caveats. PixMovo's image tool converts between still JPEG, PNG, and WebP and does not produce animation, so animated WebP is a delivery consideration rather than something you would export here. When you do use animated WebP, verify playback in your target browsers and keep a source you can re-render, because not every viewer or editor handles animated WebP the same way as a still image.
Browser delivery and fallback
WebP is supported by current versions of all major browsers, which makes it a strong default for web delivery today. Even so, very old clients, some email software, and certain third-party tools may not decode WebP.
The safe pattern is progressive enhancement: serve WebP to clients that accept it and fall back to PNG or JPEG for those that do not. The HTML picture element lets the browser pick the first source type it supports, so modern visitors get the smaller WebP while older ones still see a compatible image.
Keep a lossless source master
Whatever you deliver, keep a lossless source. If your master is a lossless PNG (or lossless WebP), you can re-export to any format later without stacking compression losses.
Exporting a lossy WebP from a lossy JPEG stacks two rounds of lossy compression and degrades the result. Always generate delivery files from the highest-quality lossless master you have, and archive that master rather than the shipped copy.
Attribute comparison
| Attribute | PNG | WebP |
|---|---|---|
| Compression modes | Lossless only | Lossless and lossy |
| Alpha transparency | Yes | Yes, including with lossy colour |
| Animation | No (still image) | Yes |
| Browser support | Universal | All current major browsers |
| Good as an editable master | Yes | Yes in lossless mode |
| Universal fallback | Yes | Needs a fallback for old clients |
When each format tends to win
- Choose WebP when your priority is smaller images for modern browsers and you can provide a fallback.
- Choose PNG when you need a universally compatible file, an editable lossless master, or a dependable fallback source.
- For flat graphics that must stay pixel-exact, use lossless mode in either format.
- For photographs on the web, lossy WebP usually beats PNG on size while looking comparable.
Worked example: shipping a transparent web graphic
- Start from a lossless master
Keep the graphic as a lossless PNG so you have an exact, editable source with alpha.
- Export a WebP for delivery
Convert the PNG to WebP in PixMovo. Use lossless WebP for flat graphics or lossy WebP with alpha for softer imagery to reduce size.
- Provide a fallback
Reference the PNG as a fallback (for example via a picture element) so clients that cannot decode WebP still render the image.
Scenario decision table
| Scenario | Recommended | Why |
|---|---|---|
| Photos | Lossy WebP | Smaller than PNG on the web while looking comparable; keep a lossless master |
| Logos | Lossless WebP or PNG | Both keep sharp edges and alpha; PNG is the more universal master |
| Screenshots | PNG or lossless WebP | Exact pixels keep UI edges and text crisp; lossless WebP can be smaller |
| Web delivery | WebP with a fallback | Ship smaller images to modern browsers and fall back to PNG or JPEG |
| Printing | PNG or lossless master | Confirm the print provider's format; avoid lossy artifacts in the final piece |
Frequently asked questions
- Is WebP better than PNG?
- Not universally. WebP can produce smaller web images and adds lossy and animation modes, but PNG is a more universal master and fallback. The best choice depends on the job.
- Does WebP support transparency like PNG?
- Yes. WebP supports an alpha channel, and it can even combine transparency with lossy colour compression, which PNG cannot do.
- Do all browsers support WebP?
- All current major browsers support WebP, but some very old clients, email software, and third-party tools may not. Provide a PNG or JPEG fallback for universal compatibility.
- Should I convert my PNG masters to WebP and delete the PNGs?
- Keep a lossless master. Deliver WebP for the web, but archive the lossless PNG (or lossless WebP) so you can re-export later without stacking compression losses.
- Is lossless WebP or lossy WebP the right mode?
- Use lossless WebP for flat graphics, logos, and anything needing exact pixels. Use lossy WebP for photographs where a smaller file matters more than exactness.
- Can WebP hold an animation?
- Yes, WebP supports animation with alpha. PixMovo's image tool works with still images, so treat animated WebP as a delivery format and verify playback in your target browsers.