Image Compression Guide — JPEG vs PNG vs WebP Explained

Choosing the right image format can cut your page weight by 50% or more. Here’s what you need to know about JPEG, PNG, and WebP to make the right call every time.

Lossy vs Lossless Compression

All image compression falls into two categories:

• Lossy — permanently discards some data to achieve smaller files. You can’t recover the original. JPEG and WebP (lossy mode) use this approach.
• Lossless — reduces file size without any data loss. The decompressed image is identical to the original. PNG and WebP (lossless mode) work this way.

Lossy compression typically produces files 5–10x smaller than lossless for photographs. The tradeoff is acceptable for most web use cases.

When to Use JPEG

JPEG is the workhorse of the web for photographs and complex images with smooth color gradients. Use it when:

• The image is a photo or has many colors
• You don’t need transparency
• File size matters more than pixel-perfect quality

A quality setting of 75–85 is the sweet spot for most photos. Below 70, you’ll start seeing visible artifacts around edges. Above 90, file size increases sharply with minimal visual improvement.

When to Use PNG

PNG excels at images with sharp edges, text, flat colors, and transparency:

• Logos and icons
• Screenshots with text
• Images that need a transparent background
• Graphics with fewer than 256 colors (use PNG-8 for even smaller files)

Avoid PNG for photographs — a 3 MB PNG photo will often be under 300 KB as a JPEG with no visible difference.

When to Use WebP

WebP supports both lossy and lossless compression and typically produces files 25–35% smaller than equivalent JPEG or PNG files. It also supports transparency (unlike JPEG) and animation (unlike PNG).

Browser support for WebP is now above 97% globally. The main reason not to use it is if you need to support very old browsers or specific tools that don’t read WebP.

Quick Format Decision Guide

Photo, no transparency     -> JPEG (quality 80) or WebP (quality 80)
Logo / icon / flat graphic -> PNG-8 or SVG
Transparency needed        -> PNG-24 or WebP
Animation                  -> WebP or GIF (WebP is much smaller)
Maximum compatibility      -> JPEG + PNG fallback
Best compression overall   -> WebP

Practical Tips for Smaller Files

• Resize before compressing. A 4000px-wide image displayed at 800px is wasting 96% of its pixels. Resize to 2x the display size for retina, no more.
• Strip metadata. EXIF data (camera info, GPS coordinates) can add 50–100 KB. Remove it unless you have a reason to keep it.
• Use progressive JPEG for images above 10 KB. They render a blurry preview first, which feels faster to users.
• Try multiple quality levels. Compress at 80, 70, and 60 — compare visually. You’ll often find 70 looks identical to 80 at half the size.

Related Tools

• Image Compressor — compress JPEG, PNG, and WebP images in your browser
• Image Converter — convert between image formats like JPEG, PNG, and WebP