Caesium is one of the most popular image optimization software available helping photographers, bloggers, webmasters, businesses or casual users at storing, sending and sharing digital pictures.

Compress up to 90%

  • Preserving the original file format.
  • No additional software required for opening compressed files.
  • Compression without visual quality loss.
  • Simple processing

Batch processing.

  • Set compression level with a simple slider.
  • Set different compression levels to each image.
  • Custom suffix support.

Image Compressor

Providing a simple yet effective interface with a real-time preview and multiple image processing at the same time, everyone will be able to reach the best result. Advanced users will find extra features, like metadata storing options or folder structure support.

Command Line Tool

If you are working on Linux or MacOSX and want to be geeky, you can use the Command Line Tools, which are the pulsing heart of Caesium. You can compress images with advanced tools very quickly. It works on the command line!

Online Compressor

Just have a few bunch of images to compress and you don't want to download a dedicated software to accomplish the task? Do it online!

What's New

  • Option to select the maximum number of threads used while multithreading #221
  • Finnish translation #224
  • Option to compress selecting a maximum output size instead of a set quality
  • Added a shortcut (CTRL+P/CMD+P) for preview #220
  • Issue a warning when compressing with "Lossless" option and/or resize/conversion to another format #181 #217
  • Add Hindi Translation by @anuragsingh6 in #219


  • Resize handles not visible in Windows Native theme #resize
  • Usage dialog too big on macOS
  • Not remembering the output format selection #216
  • A bug preventing selection and preview without reordering (macOS only)
  • Some strings not translating correctly