Image Compressor

About This Tool

Image compression reduces the file size of an image without significantly affecting its perceived visual quality. This tool uses the browser's native Canvas API to re-encode your images on the client side — no files are ever uploaded to a server. Your images stay on your device, ensuring complete privacy and security.

The tool supports JPEG, PNG, WebP, and GIF input formats and can output compressed versions in JPEG, PNG, or WebP format. The quality slider lets you control the trade-off between file size and image quality, with instant before/after comparison so you can see exactly what you are getting before you download.

Common Use Cases

• Optimizing website images to improve page load speed and reduce bandwidth costs
• Compressing photos before sending them as email attachments to meet size limits
• Reducing image file sizes for faster social media and messaging app uploads
• Saving storage space on your device by compressing large image collections
• Converting images between formats (e.g., PNG to JPEG) for better compatibility
• Preparing images for use in presentations or documents where file size matters

Pro Tips

• For web use, WebP typically offers the best compression-to-quality ratio — try quality 70-80 for a good balance
• JPEG is best for photographs and complex images with smooth gradients; avoid it for screenshots or text-heavy images
• PNG is lossless, so compression will be minimal — use it only when you need transparency or pixel-perfect output
• A quality setting of 80-90 is often indistinguishable from the original for photos, while achieving 40-60% file size reduction
• Reduce image dimensions before compressing if the image is larger than needed — this has a far bigger impact on file size

Frequently Asked Questions

What is the difference between lossy and lossless compression?

Lossy compression (JPEG, WebP with lower quality) permanently removes some image data to achieve smaller file sizes, which may cause visible artifacts at very low quality settings. Lossless compression (PNG, WebP at 100%) preserves every pixel exactly but achieves much smaller file size reductions.

Is there a limit on image size?

Since everything runs in your browser, the practical limit depends on your device's available memory. Very large images (over 8000px on a side) may cause performance issues on lower-end devices, but most standard photos and screenshots work without problems.

Are my images uploaded to a server?

No. All processing happens entirely in your browser using the Canvas API. Your images never leave your device. This makes the tool completely private and secure, ideal for sensitive or confidential images.

Why does PNG compression show no size reduction?

PNG is a lossless format, meaning it preserves every pixel exactly. The compression in this tool re-encodes the image as PNG, which will not reduce file size significantly. For PNG files, consider converting to JPEG or WebP for actual size savings.

What quality setting should I use?

For web use, start at 80 and adjust down until you notice quality loss. For photographs, 70-85 is a good range. For screenshots with text, use 85-95 to keep text readable. Below 50 you will typically start seeing visible artifacts.

Need more tools? Try the Base64 Encoder/Decoder. Part of the FreeQ.One tools suite.