How to Compress Images Without Losing Quality [2024 Guide]

Image compression is crucial for website performance, email deliverability, and storage management. But how do you reduce image file size without making photos look terrible?

This guide covers expert techniques to compress images up to 80% smaller while maintaining visual quality.

Why Image Compression Matters

For Websites

Page speed: Large images are the #1 cause of slow websites
SEO ranking: Google uses page speed as a ranking factor
User experience: Visitors leave slow-loading pages
Bandwidth costs: Smaller images = lower hosting costs

For Email

Deliverability: Large attachments get blocked or filtered
Mobile viewing: Compressed images load faster on phones
Inbox limits: Stay under attachment size limits

For Storage

Cloud storage: Fit more photos in limited space
Device storage: Free up phone and computer space
Backup speed: Smaller files backup faster

Understanding Image Compression

Lossy vs. Lossless Compression

Lossy compression removes some image data permanently:

Smaller file sizes (60-80% reduction)
Some quality loss (often imperceptible)
Best for photos (JPG)
Cannot restore original quality

Lossless compression removes redundant data without quality loss:

Moderate file size reduction (20-40%)
No quality loss
Best for graphics, screenshots (PNG)
Original quality preserved

Best Formats for Compression

Format	Type	Best For	Compression
JPG/JPEG	Lossy	Photos	Up to 80%
PNG	Lossless	Graphics, transparency	Up to 40%
WebP	Both	Web images	Up to 90%
AVIF	Lossy	Modern browsers	Up to 95%

Method 1: Compress Images Online (Easiest)

The fastest way to compress images is using a free online tool:

How to Compress Images Online:

Go to Percime Image Compressor
Upload your images (drag and drop multiple files)
Choose compression level or use smart auto-compression
Download compressed images

Results You Can Expect:

Photos: 60-80% smaller
Screenshots: 40-60% smaller
Graphics: 30-50% smaller

Method 2: Compress Images for Web

When optimizing images for websites, follow these best practices:

Recommended Settings for Web:

Quality: 80-85% for JPG (sweet spot)
Max dimensions: 1920px width for full-width images
Format: WebP with JPG fallback
DPI: 72 (screen resolution)

Code Example (HTML):

<picture>
  <source srcset="image.webp" type="image/webp">
  <img src="image.jpg" alt="Description" loading="lazy">
</picture>

Method 3: Batch Compress Multiple Images

For large numbers of images:

Online Batch Compression

Upload all images at once to Percime Tools
All images compress simultaneously
Download as ZIP file

Desktop Tools

ImageOptim (Mac): Drag and drop batch compression
FileOptimizer (Windows): Right-click compression
Squoosh (Web): Advanced settings per image

Command Line (for developers)


mogrify -quality 85 -strip *.jpg


jpegoptim --max=85 *.jpg

Method 4: Compress Images on iPhone

Built-in Options

iOS doesn't have native compression, but you can:

Take photos in "High Efficiency" mode (HEIC)
Share photos via Mail (it offers to reduce size)

Using Online Tools

Safari works great with online compressors — upload directly from your photo library.

Method 5: Compress Images on Android

Google Photos

Settings > Backup > High quality (compresses automatically)

Online Tools

Chrome on Android works with all online image compressors.

Expert Compression Techniques

1. Start with the Right Dimensions

Don't compress a 5000px image to use at 500px. Resize first, then compress.

2. Remove Metadata (EXIF)

Camera metadata adds 10-50KB per image. Strip it for web images:

Location data
Camera settings
Thumbnail previews

3. Use Progressive JPEGs

Progressive JPGs load in stages, appearing faster to users even at the same file size.

4. Choose the Right Quality Level

Use Case	Recommended Quality
Thumbnails	60-70%
Web photos	80-85%
Social media	85-90%
Print	95-100%

5. Consider Modern Formats

WebP and AVIF offer 25-50% better compression than JPG:

WebP: 95% browser support
AVIF: 75% browser support (growing)

Compression Quality Comparison

Here's what different compression levels look like:

100% Quality (Original): 2.5 MB

Perfect quality
Not suitable for web

85% Quality: 450 KB (82% smaller)

Virtually identical to original
Ideal for most uses

70% Quality: 200 KB (92% smaller)

Minor artifacts visible on close inspection
Good for thumbnails

50% Quality: 100 KB (96% smaller)

Noticeable quality loss
Only for very small images

Common Compression Mistakes

Mistake 1: Over-Compressing

Problem: Images look pixelated or have visible artifacts Solution: Stay at 75-85% quality for most uses

Mistake 2: Compressing Already Compressed Images

Problem: Quality degrades with each compression Solution: Always compress from the original file

Mistake 3: Wrong Format Choice

Problem: Using PNG for photos (huge files) Solution: Use JPG for photos, PNG for graphics with transparency

Mistake 4: Ignoring Dimensions

Problem: Compressing 4000px images for 400px display Solution: Resize to actual display size first

Image Compression for Different Platforms

WordPress

Install a plugin like ShortPixel or Smush
Enable automatic compression on upload
Bulk optimize existing images

Shopify

Use the built-in image optimization
Upload images at 2048px max width
Consider apps like TinyIMG for bulk optimization

Social Media Recommendations

Platform	Max Dimensions	Format
Instagram	1080x1350	JPG 85%
Facebook	1200x630	JPG 80%
Twitter	1600x900	JPG/PNG
LinkedIn	1200x627	JPG 85%

Frequently Asked Questions

Does compressing images reduce quality?

Lossy compression (JPG) reduces quality slightly, but at 80-85% quality the difference is usually invisible. Lossless compression (PNG) maintains perfect quality.

What's the best free image compressor?

For most users, online tools like Percime Image Compressor offer the best combination of ease-of-use and quality. For developers, ImageOptim (Mac) and FileOptimizer (Windows) are excellent.

How much can I compress an image?

Typically 60-80% for photos without visible quality loss. Graphics and screenshots may compress 30-50%.

Should I compress images before or after editing?

Always edit at full quality, then compress as the final step. Compressing before editing can cause quality issues.

What's better: JPG or PNG?

JPG for photos and complex images. PNG for graphics, logos, and images needing transparency.

Conclusion

Compressing images doesn't have to mean sacrificing quality. With the right techniques and tools, you can reduce file sizes by 60-80% while keeping images looking great.

Start with our free image compressor — it's fast, maintains quality, and works on any device.