JPEG vs PNG vs WebP: Which Image Format Should You Use?
A practical comparison with real file sizes. Tested the same photo saved as JPEG, PNG, and WebP so you don't have to guess.
JPEG, PNG, or WebP?
I ran into this question again last week while exporting photos for a friend’s portfolio site. JPEG? PNG? WebP? The answer is always “it depends,” but what it depends on is pretty straightforward once you see the numbers.
I grabbed four test images, ran them through all three formats, and noted down every file size. Here’s what I found.
The Three Formats, Fast
JPEG has been around since 1992. It uses lossy compression, which means it throws away some image data to keep files small. Great for photographs. Not great for text, sharp edges, or anything with a transparent background (it doesn’t support transparency at all).
PNG came out in 1996 as a better alternative to GIF. Lossless compression, so nothing gets thrown away. Every pixel stays exactly where it was. It handles transparency perfectly. The trade-off? Files get big fast, especially for complex photos.
WebP is the new kid. Google introduced it in 2010, but it took years for browsers to catch up. It supports both lossy and lossless compression, plus transparency. In most cases, a WebP file is 25 to 35% smaller than the equivalent JPEG, and dramatically smaller than PNG.
Short version: JPEG for photos, PNG for sharp graphics and transparency, WebP for everything (if your stack supports it).
Real File Size Tests
I tested four images on my 2023 MacBook Pro. All exports done at the same resolution, no resizing. Quality set to 80 for lossy formats. Here’s what came out:
| Image | JPEG | PNG | WebP (lossy) | Visible difference? |
|---|---|---|---|---|
| Sunset photo (4.2 MP) | 892 KB | 6.4 MB | 614 KB | None at normal zoom |
| Website screenshot | 248 KB | 1.1 MB | 174 KB | JPEG had slight blur on text |
| Logo (transparent bg) | N/A (no transparency) | 28 KB | 18 KB | Identical |
| Product photo (white bg) | 134 KB | 1.8 MB | 98 KB | None |
A few things jumped out at me.
The sunset photo tells the whole story. PNG bloated to 6.4 MB because lossless compression has to store every single color gradient in that sky. JPEG got it down to 892 KB. WebP beat JPEG by another 31%, and I could not spot any quality difference side by side on my screen.
The screenshot test is where PNG actually wins. Text and sharp lines get muddy with JPEG compression. You can see it if you zoom in even a little. PNG kept everything crisp. WebP did too, at a fraction of the size.
For the logo, JPEG straight up can’t handle transparency. No comparison there. WebP delivered the same clean edges as PNG but shaved off 36%.
The product photo result surprised me a little. WebP was 27% smaller than JPEG with zero visible quality loss. I zoomed to 300% and still couldn’t tell them apart.
When to Use Each Format
Here’s the decision process I use now.
Use JPEG when:
- You’re saving photographs for the web
- File size matters more than pixel-perfect accuracy
- You don’t need transparency
Use PNG when:
- You need a transparent background (logos, overlays, icons)
- The image has text or sharp geometric shapes
- You’re taking screenshots for documentation
Use WebP when:
- You want the smallest file possible
- You need transparency and small size
- You’re building a modern website and can control the markup
One thing I want to call out: if you’re working with screenshots that need to look perfect, stick with PNG. JPEG compression artifacts around small text will drive you crazy. I made that mistake once on a tutorial and had to redo all the images.
How to Convert Between Formats
You don’t need desktop software for this anymore. I use the image format converter on ImgPrism when I need to switch formats quickly. It runs entirely in your browser, so your images never leave your machine.
The process takes about ten seconds. Drop your file in, pick the output format, and download the result. I converted all four test images for this article in under a minute.
If you’re doing batch conversions for a whole website, you can queue up multiple files at once. I’ve run batches of 30+ images without any issues.
Is WebP Safe to Use in 2025?
Yes. As of early 2025, WebP works in every major browser. Chrome, Firefox, Safari, Edge, Opera, Samsung Internet. Even the browsers built into smart TVs handle it now.
The last holdout was Safari on older iOS versions, but Apple added full WebP support in iOS 14, which shipped in 2020. Anyone running a phone from the last five years can view WebP images without any problems.
If you’re really worried about edge cases, you can use the <picture> element in HTML to serve WebP with a JPEG fallback:
<picture>
<source srcset="photo.webp" type="image/webp">
<img src="photo.jpg" alt="A sunset over the ocean">
</picture>But honestly, at this point the fallback is mostly for peace of mind. I’ve been serving WebP-only images on my personal projects for over a year with zero complaints.
The Format I Reach For
Nine times out of ten, I go with WebP. The file size savings are real, the quality is there, and browser support is no longer a concern. The only time I skip it is when someone specifically asks for PNG (usually for print or design tool workflows) or when I’m taking screenshots where every pixel matters.
If you’re not sure, try converting one of your images to all three formats and compare them yourself. The numbers don’t lie.