How to Compress Images Online for Free
Need to compress images online for free? Whether you're optimizing for a website, reducing email attachment sizes, or saving storage space, image compression is quick and easy with the right tool.
Step 1: Choose a Free Image Compressor
The best free image compressors are browser-based tools that don't require downloads or sign-ups. Compresso is a free online image compressor that works entirely in your browser — your images never leave your device.
Step 2: Upload Your Images
Go to compresso.io and drag and drop your images onto the page, or click to browse your files. Compresso supports PNG, JPG/JPEG, and WebP formats. You can upload multiple files at once for batch compression.
Step 3: Adjust Quality Settings
Use the quality slider to set your desired compression level. Here are recommended settings:
- Web images: 70-80% quality (best balance of size and quality)
- Social media: 75-85% quality
- Email attachments: 60-70% quality
- High-quality prints: 90-95% quality
Step 4: Optionally Resize
If your images are larger than needed, resize them before compressing. Compresso lets you set maximum width and height while maintaining aspect ratio. For web use, most images don't need to be wider than 1200-1600 pixels.
Step 5: Download Your Compressed Images
Click download to save your compressed images. If you processed multiple files, you can download them all as a ZIP archive. Compresso shows the original and compressed file sizes so you can see exactly how much space you saved.
Tips for the Best Compression Results
- Choose the right format: JPG for photos, PNG for graphics with transparency, WebP for the best compression
- Resize first: Reducing dimensions before compressing gives the biggest savings
- Convert to WebP: WebP files are 25-35% smaller than JPG at the same quality
- Don't over-compress: Below 60% quality, artifacts become noticeable
- Batch process: Compress all your images at once for consistency
How Much Can You Reduce File Sizes?
Typical compression results with Compresso:
- JPG photos: 50-80% smaller (a 5MB photo → under 1MB)
- PNG graphics: 40-70% smaller
- WebP images: 20-50% smaller (already efficient format)
Why Use a Client-Side Compressor?
Unlike server-based tools like TinyPNG or iLoveIMG, Compresso processes images entirely in your browser. This means:
- Complete privacy — your images never leave your device
- No file size limits — no 5MB or 10MB caps
- Instant results — no upload/download wait times
- Works offline — once loaded, no internet needed
Ready to compress? Try Compresso free — no sign-up required.