JPG vs PNG vs WebP: Which Should You Use?
The short version, then the details that actually matter for your specific image.
The quick answer
If you just need a rule of thumb: use JPG for photos where small file size matters more than pixel-perfect edges, PNG when you need transparency or perfectly sharp lines (logos, screenshots, diagrams) and don't want any quality loss, and WebP when you want the smaller file size of JPG-style compression but with PNG-style transparency support, and your platform accepts it. The rest of this guide explains why, with real numbers.
How each format actually compresses
JPG (JPEG) is a lossy format. It breaks your image into small 8×8 pixel blocks, and for each block it keeps the color and brightness patterns your eye notices most and discards the ones it's less sensitive to. That's why JPG files can get extremely small — but push the compression too far and you start to see blotchy square artifacts, especially around sharp edges and text.
PNG is lossless. It compresses data the way a zip file does — finding repeated patterns and encoding them more efficiently — without throwing anything away. A PNG will always look pixel-identical to the source, but that guarantee comes at the cost of a larger file, especially for photos with lots of fine detail and gradients.
WebP, developed by Google and released in 2010, supports both modes in one format: lossy compression that typically beats JPG at the same visual quality, and lossless compression that typically beats PNG. It also supports transparency in both modes, which JPG never has.
Real file size differences
These are typical ranges we see comparing formats at visually equivalent quality — actual results vary by image content:
- Photo (JPG vs WebP, lossy): WebP is usually 25-35% smaller than an equivalent-quality JPG.
- Screenshot or UI graphic (PNG vs WebP, lossless): WebP is usually 20-30% smaller than an equivalent PNG.
- Photo saved as PNG instead of JPG: the PNG is very often 3-5× larger, since lossless compression can't discard the fine photographic detail JPG safely throws away.
- Simple graphic (flat colors, few gradients) as JPG vs PNG: the gap narrows a lot, and PNG can sometimes win, since there's little detail for JPG's lossy compression to exploit.
Transparency
JPG has never supported transparency — any transparent area in a source image gets filled with a solid color (usually white) when you save as JPG. PNG and WebP both support full alpha transparency, meaning smooth, partial transparency (like a soft drop shadow fading to nothing), not just a hard on/off mask.
Browser and software support
All major browsers — Chrome, Firefox, Edge and Safari — have supported WebP since 2020, so for a website it's now a safe default. Compatibility gets patchier outside the browser: some older desktop image editors, a handful of printers, and some upload forms still only accept JPG or PNG. If you're sending an image somewhere you don't control, PNG (for graphics) or JPG (for photos) remains the safest universal choice.
Decision guide
Choose JPG when…
It's a photo, file size matters, you don't need transparency, and it needs to open absolutely everywhere.
Choose PNG when…
You need transparency or perfectly sharp edges (logos, screenshots, text) and want zero quality loss, or maximum compatibility with transparency.
Choose WebP when…
You want the smallest possible file — for a website, an app, or storage — and your platform accepts it.
Frequently Asked Questions
Is WebP always smaller than JPG?
Usually, but not always. For ordinary photos, WebP is typically 25-35% smaller than JPG at equivalent visual quality. For very simple images (flat colors, screenshots, line art), the gap is smaller and can occasionally reverse, especially with an aggressive JPG quality setting.
Why does my photo look blocky after saving as JPG?
JPG divides the image into small blocks and discards detail the eye is less sensitive to. At low quality settings, those block boundaries become visible as blotchy squares, especially around sharp edges and text — a compression artifact, not a bug in your software.
Can I convert a JPG to PNG to fix quality loss?
No. Once a JPG has been compressed, the discarded detail is gone for good — converting to PNG afterward just locks in the existing quality loss inside a larger, lossless file. To avoid this, start from the original uncompressed source next time, if you still have it.
Does PNG support transparency the same way as WebP?
Both support full alpha transparency (smooth, partial transparency, not just an on/off mask), so visually they behave the same way. The difference is file size: WebP usually compresses transparent images smaller than PNG for the same visual result.
Will an old browser or app fail to open a WebP file?
It's rare today — all major browsers have supported WebP since 2020, including Safari. The exceptions are older desktop software (some versions of Photoshop before 2021, some image viewers) and a handful of platforms that still require JPG or PNG for uploads. Check the specific tool if you're unsure.
Which format should I use for a website logo?
PNG or WebP — both preserve sharp edges and transparency. WebP is usually the better default for the web today since it produces a smaller file at the same quality; keep a PNG version around as a universal fallback if your platform doesn't support WebP uploads.