Image Compressor – Compress Images Online Free
Image Compressor is a free online tool that reduces the file size of JPG, PNG, WebP, and GIF images directly in your browser. It works by re-encoding images using WebAssembly-powered compression with an adjustable quality setting. Users can compress up to 5 images at once, preview the before/after result, and download the compressed files — all without uploading anything to a server.
Your images never leave your device. All compression happens locally in your browser using WebAssembly. No upload, no server, no storage.
How to Compress Images Online Free
- 01
Upload your images
Drag and drop up to 5 images onto the upload zone, or click to open the file picker. JPG, PNG, WebP and GIF are all supported.
- 02
Adjust quality and compress
Set the quality slider for each image (default 80 is recommended), then click "Compress All". The browser-image-compression library processes each file in a Web Worker — your UI stays responsive.
- 03
Download the results
See the before/after file sizes and the percentage saved. Download individual images or click "Download All" to save everything at once.
Features
- ✓Compress JPG, PNG, WebP and GIF
- ✓Adjustable quality slider per image (0–100)
- ✓Batch compress up to 5 images at once
- ✓Before/after size comparison with savings %
- ✓Web Worker processing — UI stays responsive
- ✓100% client-side — files never leave your device
- ✓Individual and bulk download
- ✓No login, no file upload, no sign-up
Why Use Privatool Image Compressor?
Most image compression tools — TinyPNG, Compressor.io, Squoosh (for some operations) — transmit your images to a remote server. That means your photos, screenshots, or design assets travel over the internet to a machine you don't control, where they may be cached, logged, or retained for a period of time.
Privatool compresses images entirely within your browser tab using the browser-image-compression library, which runs in a Web Worker so your page stays interactive during heavy processing. The compressed file is assembled in memory and downloaded directly — no upload, no server round-trip, no privacy risk.
Frequently Asked Questions
Is image compression free?
Yes, completely free. You can compress up to 5 images at once with no login or account required. Images are processed entirely in your browser.
Are my images uploaded to a server?
No. All compression happens locally in your browser using WebAssembly and the browser-image-compression library. Your images never leave your device and are never sent to any server.
What image formats are supported?
JPG, JPEG, PNG, WebP, and GIF are supported. The compressed output preserves the original file format by default.
How much can image file size be reduced?
Compression results vary by image content and quality setting. Typical results are 50–80% size reduction for photos, with minimal visible quality loss at the default quality of 80. PNG images with large areas of solid colour may compress even more.
What does the quality slider control?
The quality slider (0–100) controls the initial compression quality passed to the image encoder. Lower values produce smaller files with more visible quality loss. The default of 80 provides a good balance between file size and visual quality.