How to Compress Images Without Losing Quality

Image compression is one of the most impactful optimizations you can apply to any website. Large image files slow down page loads, increase bandwidth costs, and hurt your Google Core Web Vitals score. In this guide we explain the best techniques for compressing images without a noticeable drop in visual quality.

Why Image Size Matters

Studies show that a 1-second delay in page load time reduces conversions by up to 7%. Images often account for 60–80% of a web page's total byte size. Reducing image weight is therefore one of the highest-ROI optimizations available to developers and content creators alike.

Lossy vs. Lossless Compression

Lossy compression permanently removes some image data to achieve smaller file sizes. JPEG and WebP are lossy formats. At quality settings of 75–85%, the difference is practically invisible to the human eye, yet file sizes can drop by 60–70%.

Lossless compression reduces file size without discarding any data. PNG files compressed losslessly retain every pixel but still benefit from efficient encoding. Tools like OptiPNG or Quarkova's browser-based compressor can reduce PNG sizes by 20–40% losslessly.

Using Quarkova to Compress Images

1. Navigate to the Image Compressor tool.
2. Click "Select image" and choose your JPG or PNG file.
3. Drag the quality slider — start at 80% for a balanced result.
4. Click "Compress and Download" to get your optimized file instantly.

All processing happens in your browser using HTML5 Canvas. Your file is never uploaded to any server, ensuring complete privacy.

Recommended Quality Settings

• Social media thumbnails: 70–75%
• Blog post images: 75–82%
• Product photos (e-commerce): 80–88%
• Portfolio / photography: 88–95%