Is my data safe? Are images uploaded to your server?

Absolutely not. All compression happens 100% in your browser using the HTML5 Canvas API and Web Workers. Your images never touch our servers — we don't even have image storage infrastructure.

What image formats are supported?

Zolkit Image Compressor supports JPG/JPEG, PNG, and WebP. The output format is preserved from the input (JPG stays JPG, etc.).

How much can I compress an image?

Results vary by image content and chosen quality level. Typically 40–80% file size reduction with minimal visible quality loss at the 60–80% quality setting.

Is there a file size or quantity limit?

There are no hard limits — you're bounded only by your browser's available memory. In practice, you can process dozens of high-resolution images at once.

What's the difference between Lossy and Lossless compression?

Lossy compression reduces file size by discarding some image data — excellent for photos where small quality loss is imperceptible. Lossless preserves every pixel but achieves smaller reductions, ideal for logos or graphics with sharp edges.

Do I need to create an account?

No account, no signup, no email required. Just open the page and start compressing.

Image Compressor

Compress JPG, PNG & WebP. 100% in-browser — your files never leave your device.

Quality: 75%

Drop images here

JPG, PNG, WebP · Multiple files at once

Compress Images Instantly — No Upload Required

Zolkit's image compressor uses your browser's built-in processing power. Nothing is ever sent to a server — your images stay on your device at all times.

100% Private

Files are processed entirely in your browser using HTML5 Canvas. Zero server contact.

Batch Processing

Drop multiple images at once and compress them all in parallel using Web Workers.

Quality Control

Fine-tune compression with a quality slider from 10% to 100% for perfect balance of size vs. quality.

Works on Mobile

Tap to open your photo gallery directly. Optimised for one-handed mobile use.

Completely Free

No account, no signup, no watermarks. Free forever.

Bulk Download

Download all compressed images as a single .zip file with one click.

How to Compress Images

1
Drag and drop your images into the upload area, or click to select files from your device.
2
Adjust the quality slider to your preference. Lower = smaller file, higher = better quality.
3
Click Download on individual images, or Download All to get a ZIP of everything.