Blog - Image Compression Guides & Tutorials

Learning how to compress images effectively is essential for web developers, content creators, and anyone working with digital images. This step-by-step guide will walk you through the process of compressing images for different use cases.

Step 1: Choose Your Compression Tool

The first step is selecting the right tool for your needs. Here are the main options:

For Quick One-Time Compression:

Use online tools like Squish web interface - simple drag and drop
TinyPNG - popular free tool
Compressor.io - good quality compression

For Automation & Integration:

Use APIs like Squish API - programmatic compression with CDN URLs
Kraken.io API - good for WordPress
Cloudinary - full image management platform

Step 2: Prepare Your Images

Before compressing, make sure your images are ready:

Check current file size - Know your starting point
Verify image dimensions - Resize if needed (don't compress unnecessarily large images)
Choose the right format - JPEG for photos, PNG for graphics with transparency
Backup originals - Keep uncompressed versions if you might need them later

Step 3: Compress Using Squish (Recommended)

Using the Web Interface:

1.Go to Squish and create a free account
2.Upload your image(s) - drag and drop or click to browse
3.Choose compression settings (quality, format, dimensions)
4.Get compressed image with instant CDN URL - ready to use immediately

Using the API:

curl -X POST https://api.isquish.dev/api/v1/compress/single \
  -H "X-API-Key: your_api_key" \
  -F "image=@photo.jpg" \
  -F "quality=80" \
  -F "format=webp"

See our API documentation for more examples.

Step 4: Choose Compression Settings

Quality Settings:

80-90: High quality, minimal compression - best for professional photography
70-80: Good balance - recommended for most web images
60-70: Higher compression - good for thumbnails or when file size is critical
Below 60: Maximum compression - use only when quality isn't critical

Format Selection:

JPEG: Best for photographs, complex images
WebP: Modern format, 25-35% smaller than JPEG
AVIF: Newest format, 50% smaller than JPEG
PNG: Use only for images needing transparency or lossless compression

Step 5: Verify Results

After compression, always verify the results:

✓Check file size reduction: Aim for 50-80% reduction while maintaining acceptable quality
✓Visual inspection: Compare original and compressed side-by-side
✓Test on different devices: Ensure images look good on mobile and desktop
✓Check load time: Use PageSpeed Insights to verify improvement

Step 6: Implement on Your Website

For Web Developers:

Use responsive images with srcset:

<img 
  src="image-800.webp" 
  srcset="image-400.webp 400w, 
          image-800.webp 800w, 
          image-1200.webp 1200w"
  sizes="(max-width: 600px) 400px, 
         (max-width: 1200px) 800px, 
         1200px"
  alt="Description"
  loading="lazy"
/>

Common Mistakes to Avoid

❌ Over-compression

Compressing too aggressively results in visible quality loss. Find the balance between size and quality.

❌ Wrong Format

Using JPEG for images with transparency or PNG for photographs wastes file size.

❌ Not Resizing First

Compressing a 4000px image to display at 800px wastes bandwidth. Resize first, then compress.

Conclusion

Compressing images is a straightforward process that can dramatically improve your website's performance. By following these steps and using the right tools, you can achieve significant file size reductions while maintaining excellent visual quality.

Ready to Start Compressing?

Try Squish free - compress images with instant CDN URLs. No credit card required.

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