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2026-07-02·3 min read

How to Batch Compress Multiple Images at Once Online Free

Compress dozens of images simultaneously without installing software. The fastest way to bulk reduce image file sizes for web or upload.


Compressing images one by one is slow. If you have dozens or hundreds of images to optimise — for a website, product catalogue, or photo archive — batch compression saves hours of work. Here is how to do it for free online.

How to Batch Compress Images at ImageResize.co

1. Open the Image Compressor 2. Click SELECT IMAGES and choose multiple files, or drag and drop a selection 3. All selected images are compressed simultaneously in your browser 4. Download each compressed image No file size limits, no watermarks, no registration. Works on JPG, PNG, and WebP.

Batch Compress to a Specific File Size

Organising Your Batch Before Compressing

  • For best results:
  • Sort by use case: Website hero images need different compression than thumbnails
  • Resize first if needed: Batch resize all images to the target display size before compressing
  • Use consistent naming: Rename files to descriptive, SEO-friendly names before uploading

Batch Compression for WordPress and CMS

For WordPress sites, batch-compress all images before uploading to the media library. Pre-compressing with our free browser-based tool is faster and free — no server resources consumed, no plugin required.

Try It Free — No Registration Needed

Resize, compress, and convert images instantly in your browser.