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6 min read
January 15, 2025

How to Compress Images Without Losing Quality (2026 Guide)

Reduce image file sizes by up to 90% without anyone noticing. Here's exactly how the quality slider works and the optimal settings for every use case.

How to Compress Images Without Losing Quality (2026 Guide)

Images account for over 50% of an average webpage's total weight. A 4MB hero image that loads in 8 seconds on mobile is a conversion killer — Google's research shows a 1-second delay reduces conversions by up to 20%.

Lossy vs Lossless Compression

Lossless compression removes metadata without touching pixel values. PNG is always lossless — typical reduction: 10–30%.

Lossy compression permanently discards some pixel data. JPEG, WebP use lossy. Typical reduction: 50–90%.

Optimal Quality Settings

  • Photos: 75–85% quality
  • Product images with fine detail: 80–90%
  • Logos on solid background: Use PNG — JPG creates visible artefacts around sharp edges
  • WebP: 25–35% Smaller Than JPG

    Image typeOriginal JPGWebP (same quality)Saving
    Portrait photo420 KB280 KB33%
    Product shot185 KB125 KB32%
    Landscape1.1 MB730 KB34%

    Safari added full WebP support in 2020. Global browser support is 97%+ in 2025.

    How to Check Quality After Compression

  • Download the compressed file
  • Zoom to 200% and examine edges — especially text overlaid on photos
  • Check shadow areas — compression artefacts appear here first
  • If you see rectangular blocks, increase quality by 5–10 points
  • Use our Image Compressor and WebP Converter to optimise your images in your browser — no uploads required.

    Written by the GMC Tools team