How the image compressor works
Image Compressor reduces image file sizes to speed up website load times, meet email attachment constraints, and save device storage. Utilizing modern HTML5 Canvas rendering and WebP compression algorithms native to your browser engine, the compression happens locally on your computer or smartphone without uploading your photos to third-party cloud servers.
You maintain complete control over visual quality with an adjustable compression slider from 10% to 100%. The compressor outputs modern WebP formatted files, which deliver up to 30% smaller file sizes than legacy JPEG files while maintaining comparable visual fidelity.
Step-by-step instructions
- Click or drag-and-drop a JPEG, PNG, or WebP image (up to 20MB) into the upload area.
- Adjust the quality slider to your desired balance of sharpness and file size reduction.
- Click Compress Image, review the instant before-and-after file size comparison, and download your optimized WebP image.
Browser-Native Canvas Re-encoding
CanvasRenderingContext2D.drawImage() → HTMLCanvasElement.toBlob(callback, 'image/webp', quality)Your image is loaded into an off-screen bitmap, rendered onto an HTML5 canvas element at original dimensions, and re-encoded into an optimized lossy WebP stream. Metadata (EXIF data) is stripped, enhancing privacy and saving additional kilobytes.
Practical example
A 4.2 MB PNG screenshot can typically be compressed at 80% quality into an indistinguishable 480 KB WebP image, representing an approximate 88% reduction in bandwidth consumption.
Frequently asked questions
Are my photos uploaded to any server or cloud database?
No. All compression is performed 100% locally on your machine using your browser's canvas graphics engine. Your files never leave your device.
Does WebP support transparency?
Yes. Unlike standard JPEG, the WebP format fully preserves alpha channel transparency from original PNG files.
Does compression overwrite my original file?
No. The compressed file is downloaded as a separate file with a .webp extension, leaving your original photo untouched.