JPEG vs PNG vs WebP: Which Image Format Should You Use?
Three formats cover almost every image you'll deal with on the web. Choosing the right one is the difference between a crisp 40 KB image and a blurry 2 MB one. Here's how they differ and a simple rule for each situation.
JPEG — the photo workhorse
JPEG (or JPG — same thing) uses lossy compression tuned for photographs. It excels at images with smooth gradients and lots of color variation: landscapes, portraits, product photos. Its weaknesses are sharp edges, where it produces visible "ringing," and transparency, which it doesn't support at all. JPEG is supported by literally everything — every browser, email client, printer, and operating system on earth — which is why it's still the safe default for attachments and uploads to older systems.
Use JPEG for: photographs, especially when you need universal compatibility.
PNG — lossless and transparent
PNG is lossless: it reproduces every pixel exactly. That makes it perfect for images with crisp edges and flat areas of color — logos, icons, screenshots, charts, and any graphic with text. It also supports a full alpha channel, so it's the standard for transparent images. The catch is file size: because it never discards data, a PNG photograph can be 5–10× larger than the equivalent JPEG. Using PNG for photos is the single most common cause of bloated pages.
Use PNG for: logos, icons, screenshots, line art, and anything needing transparency.
WebP — the modern all-rounder
WebP, developed by Google, supports both lossy and lossless modes plus transparency and animation in a single format. In practice WebP files are typically 25–35% smaller than a JPEG of the same visual quality, and significantly smaller than PNG for transparent graphics. Browser support is now effectively universal — every major browser has supported it for years. The only place you might avoid it is very old software or some email clients that still don't recognize it.
Use WebP for: almost everything on a modern website, when you want the smallest files.
Quick decision rule
- Photo on a website? → WebP.
- Photo for email or an old system? → JPEG.
- Logo, icon, screenshot, or chart? → PNG (or lossless WebP).
- Needs transparency? → WebP or PNG.
- Needs animation? → WebP (or keep an existing GIF).
Format choice when a website has upload rules
The best-looking format is not always the format the receiving website accepts. Check both the file type and the file-size limit in the form before converting. A smaller WebP still fails if the form only accepts JPEG, and changing the filename extension does not change the file's actual format.
| What the upload asks for | Good starting choice | Check before sending |
|---|---|---|
| JPG or JPEG photo | JPEG | Some forms reject WebP even when it is smaller. |
| Transparent logo or icon | PNG or WebP | JPEG removes transparency and uses a solid background. |
| Screenshot with small text | PNG | Lossy compression can blur fine text and sharp edges. |
| Website photo, format flexible | WebP | Keep a JPEG copy for tools that do not accept WebP. |
Why the same photo has different file sizes
Pixel dimensions, image detail, noise, and transparency all affect the final size. Two photos saved at the same quality setting can differ substantially: foliage, hair, and textured backgrounds are harder to encode compactly than a plain wall. A format comparison is meaningful only when you compare the same image at similar visual quality and dimensions. For a practical file-size target, use the dedicated 50 KB image compressor or the 50 KB JPEG compressor when the extension must stay .jpg.
A note on file extensions and "converting"
Renaming a file from .png to .jpg does not convert it — the data inside is still PNG, and most software will reject it. Real conversion re-encodes the pixels in the new format. You can convert between JPEG, PNG, and WebP for free in your browser with the PixelTools converter; just pick the output format before downloading. To learn how to keep quality high while shrinking the result, see how to compress images without losing quality.