PNG vs JPG vs WebP: Which Image Format Should You Use?

Every time you save or export an image, you make a choice that affects file size, quality, transparency, and compatibility. PNG, JPEG, and WebP dominate web image use, but they work very differently—and using the wrong format for the job is one of the most common causes of unnecessarily large files or poor-looking images.

This guide explains exactly what each format does, when to use each one, and how to pick the right format every time.

JPEG (JPG): the workhorse of web photography

JPEG is a lossy format—it discards image data when compressing to reduce file size. The algorithm analyzes the image and removes detail that the human eye is least likely to notice, particularly in areas of subtle color variation.

Use JPEG for:

• Photographs and realistic imagery
• Images without transparency
• Any situation where legacy compatibility is required
• Print files when your print provider requires it

Avoid JPEG for:

• Screenshots with text or fine lines (JPEG blurs edges)
• Images that need a transparent background
• Logos and icons (use SVG or PNG)
• Images you'll edit and re-save multiple times (each save degrades quality further)

JPEG quality is set on a 0–100 scale. The sweet spot for web use is 75–85: the visual result is indistinguishable from the original at normal viewing distances, but the file is significantly smaller. Going above 90 gives diminishing returns; the file grows substantially without meaningful quality improvement.

PNG: lossless, transparent, and large

PNG uses lossless compression—no image data is discarded. Every pixel is stored exactly as it was, which makes it ideal for images that need to stay crisp across repeated edits or exports.

Use PNG for:

• Screenshots, especially those with text or UI elements
• Logos and graphics with hard edges
• Images that need a transparent background in older environments
• Source files for graphics you'll edit repeatedly

Avoid PNG for:

• Full-resolution photographs (the files will be enormous compared to JPEG or WebP)
• Any image where you don't need transparency and file size matters

A common misconception is that PNG is "higher quality" than JPEG for photos. For photography, JPEG at 90% quality is visually equivalent to PNG and a fraction of the size. PNG's losslessness only matters when exact pixel reproduction is required—screenshots, pixel art, icons.

PNG-8 vs PNG-24: PNG-8 supports 256 colors (like GIF), suitable for simple graphics. PNG-24 supports millions of colors plus full transparency, suitable for complex images. Most modern image tools default to PNG-24.

WebP: the modern standard

WebP was developed by Google specifically for web delivery. It offers both lossy and lossless compression modes, supports transparency in both modes, and consistently beats JPEG and PNG on file size at equivalent quality.

Use WebP for:

• All photographs and images on modern websites
• Images with transparency on modern web projects
• Any situation where you're already using JPEG or PNG and want smaller files

Avoid WebP when:

• You need compatibility with Internet Explorer or very old Safari versions
• You're providing images to a third-party system that only accepts JPEG or PNG
• Your image editing tool doesn't support WebP export (though most modern tools now do)

WebP lossy mode is 25–35% smaller than JPEG at the same visual quality. WebP lossless mode is 26% smaller than PNG on average. For most web projects, switching from JPEG to WebP is the single highest-impact image optimization you can make.

AVIF: the next step

AVIF is newer still—based on the AV1 video codec, it achieves even better compression than WebP, particularly at low quality settings where JPEG and even WebP show artifacts. AVIF is now supported in Chrome, Firefox, and Safari.

Use AVIF where you need maximum compression and can use the HTML <picture> element to provide a fallback:

<picture>
  <source srcset="image.avif" type="image/avif">
  <source srcset="image.webp" type="image/webp">
  <img src="image.jpg" alt="Description">
</picture>

This serves AVIF to browsers that support it, WebP as the fallback, and JPEG for any remaining legacy browsers—giving you the best quality-to-size ratio at every compatibility level.

Side-by-side comparison

Format	Compression	Transparency	Best for
JPEG	Lossy	No	Photos, legacy compatibility
PNG	Lossless	Yes	Screenshots, logos, transparency
WebP	Lossy + Lossless	Yes	All modern web images
AVIF	Lossy + Lossless	Yes	Maximum compression, modern browsers
SVG	N/A (vector)	Yes	Icons, logos, illustrations
GIF	Lossless (256 colors)	Yes (1-bit)	Simple animations (use WebP animation instead)

How to convert between formats

The FixTools Image Format Converter handles all common format conversions in your browser. Drop in your image, choose the target format, and download the result. No uploads to a server, no account required.

A practical workflow for existing sites:

1. Identify your largest JPEG and PNG images using browser DevTools (Network tab, filter by Img)
2. Convert them to WebP using the Image Format Converter
3. Replace the <img src> references or configure your server to serve WebP automatically
4. Verify with Lighthouse that your image formats score improved

Most modern web frameworks serve WebP automatically when available. Next.js does this through the built-in <Image> component. WordPress with a caching plugin like WP Rocket handles it at the CDN level.

The format you choose won't make or break your site—but choosing well means smaller files, faster pages, and better scores without touching a single line of your actual content.