Online Free Image Compressor Online UniConverter allows you to compress images, reduce image file size online for free without losing quality. The compressed files can be saved to Dropbox and Google Drive or downloaded directly. How to compress images? Step 1. Click the Image Compressor extension icon on the top right corner of your Chrome browser. It will open an online free Image Compressor. Step 2. Drag and drop or click the Choose Files button to import image files you want to compress. Step 3. Hit the COMPRESS button to start the image compression process. Step 4. Click the DOWNLOAD button to get the compressed files.