JPG vs PNG — which format when?

The short answer

JPG for photos and complex images with many colors. PNG for graphics, screenshots, logos and anything that needs transparency. That's the rule of thumb — but the details matter.

What is JPG?

JPG (or JPEG — Joint Photographic Experts Group) is the most widely used image format in the world. It uses a lossy compression algorithm that permanently discards image information to reduce file size.

At low quality settings, characteristic "artifacts" appear — blurry blocks especially in high-contrast areas. At 80–90% quality these are nearly imperceptible to the human eye, but the file is significantly smaller than the original.

• Supports 16.7 million colors (24-bit)
• No transparency (no alpha channel)
• Lossy compression — every edit and re-save degrades quality
• Universally supported on every device
• Ideal for photos, typically 60–200 KB at web quality

What is PNG?

PNG (Portable Network Graphics) was developed as a free replacement for the patent-encumbered GIF format. It uses lossless compression — no pixel is lost.

PNG supports a full alpha channel for transparency, making it the first choice for logos, icons and graphics that need to work on different backgrounds. Because no information is discarded, PNG files for photos are significantly larger than the equivalent JPG.

• Lossless compression — perfect quality
• Full transparency support (alpha channel)
• Supports 8-bit (PNG-8) and 24-bit (PNG-24) color depth
• Ideal for graphics, logos, screenshots, illustrations
• Larger files than JPG for photographic content

Head-to-head comparison

When to use JPG

JPG is the right choice when:

• You have photos or images with many natural colors and gradients
• No transparent background is required
• File size matters (e.g. for fast page loads)
• The image won't be edited further
• Images for social media, blogs, online shops

When to use PNG

PNG is the right choice when:

• Transparency or a transparent background is needed
• The image contains text or sharp edges (e.g. screenshots)
• The image will be edited further
• Logos, icons or graphics with few colors
• Pixel-accurate rendering matters (e.g. QR codes, diagrams)

What about WebP?

WebP is Google's modern image format and offers the best of both worlds: lossy compression like JPG, lossless compression like PNG, and full transparency support. File sizes are typically 25–35% smaller than the equivalent JPG or PNG. For new web projects WebP is worth a look — every modern browser supports it.

Conclusion

For most web projects: photos as JPG (70–85% quality), graphics and logos as PNG or WebP. If you need maximum compatibility: JPG and PNG. If you're building modern, lean websites: WebP for both. JNRT Pixel supports all three formats directly in the browser.