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Caesium Image Compressor
What Caesium Image Compressor is
Caesium Image Compressor compresses digital pictures for storage, sending, and sharing, with desktop and online options. The maker says pictures can be reduced by up to 90% without visible quality loss. Its desktop interface offers real-time previews, batch processing, resizing, metadata storage options, and folder structure support. JPG, PNG, WebP, and TIFF are the listed formats. The online compressor works without dedicated software, states that images never leave your device, and includes a lossless option that preserves image quality completely. It accepts up to 10 files at a time, with a 20 MB maximum per file. The software is free. The current Windows desktop version is 2.8.5 and supports Windows 10 build 1809 or later; a portable download is also listed. The macOS desktop version supports macOS 12 or later. Linux users can compile the source or obtain a third-party binary build; the project README reports testing on Ubuntu 22.04 and Manjaro. The project README directs users to open an issue for troubleshooting or feature requests.
Who it suits
It suits photographers, bloggers, webmasters, businesses, and casual users who need to compress, resize, or batch-process images. The online option is useful for people who want to avoid downloading dedicated software.
What it does well
- Free plan listed as free
- Batch processing and real-time desktop preview
- Supports JPG, PNG, WebP, and TIFF
- Online compressor states images stay on-device
What to know first
- Online compressor limits files to 10 at a time
- Online files are limited to 20 MB each
- Linux requires source compilation or a third-party build
- Desktop versions require Windows 10 build 1809+ or macOS 12+
Limits
The online compressor accepts up to 10 files at a time, with a maximum of 20 MB per file. The listed Windows desktop version requires Windows 10 build 1809 or later, and the macOS version requires macOS 12 or later; Linux requires compiling the source or using a third-party build.
Plans
| Plan | Billed and limits | Price |
|---|---|---|
| Caesium Image Compressor | Free software; Windows 10 (build 1809+) and macOS 12+ downloads listed; Linux requires source compilation or a third-party build | Free |
As saerasoft.com lists them, read 10 Oct 2026. The maker's own page has the final word.
Getting started
- Visit the Caesium website.
- For online compression, open the online compressor without downloading dedicated software.
- For Windows, download the installer or portable version; the listed desktop version requires Windows 10 build 1809 or later.
- For macOS, download the DMG; the listed desktop version requires macOS 12 or later.
- For Linux, compile the source or obtain a third-party binary build.
Verdict
Caesium covers image compression alongside resizing, batch processing, and metadata options, with desktop and browser-based use. Check the file-size limits for the online compressor and the platform-specific desktop requirements before choosing it.
Questions
How much does Caesium Image Compressor cost?
It is free software, listed as free.
Which image formats does it support?
The listed formats are JPG, PNG, WebP, and TIFF.
Can I use it online?
Yes. Caesium offers an online compressor that does not require downloading dedicated software. It accepts up to 10 files at a time and 20 MB per file.
Which desktop platforms are supported?
The listed platforms are Windows, macOS, and Linux. The current Windows version supports Windows 10 build 1809 or later, and the macOS version supports macOS 12 or later.
Does Caesium have a lossless option?
The online compressor has a lossless mode that preserves image quality completely.
Who maintains Caesium?
Its creator and maintainer identifies himself as Matteo, a developer from Italy. He says the project started more than 10 years ago.
Facts from Caesium Image Compressor's own pages
- Advanced options
- The desktop product includes metadata storage options and folder structure support. · saerasoft.com, 10 Oct 2026
- Batch processing
- Yes · saerasoft.com, 20 Sept 2026
- Command line
- Caesium offers command-line tools for fast image compression with advanced tools. · saerasoft.com, 10 Oct 2026
- Compression
- The maker says pictures can be compressed up to 90% without visible quality loss. · saerasoft.com, 10 Oct 2026
- Compression modes
- both · saerasoft.com, 20 Sept 2026
- Free plan
- Yes · saerasoft.com, 20 Sept 2026
- Linux support
- The project README says Linux has been tested on Ubuntu 22.04 and Manjaro, and users can compile the source or obtain a third-party binary build. · github.com, 10 Oct 2026
- Lossless mode
- The online compressor has a lossless compression option that preserves image quality completely. · caesium.app, 10 Oct 2026
- macOS support
- The current listed desktop version supports macOS 12 or later and is available as a DMG. · saerasoft.com, 10 Oct 2026
- Maker
- The creator and maintainer identifies himself as Matteo, a developer from Italy, and says the project started more than 10 years ago. · saerasoft.com, 10 Oct 2026
- Metadata controls
- Yes · saerasoft.com, 20 Sept 2026
- Online compressor
- Caesium also offers an online compressor that can be used without downloading dedicated software. · saerasoft.com, 10 Oct 2026
- Online limits
- The online compressor allows up to 10 files at a time and a maximum of 20 MB per file. · caesium.app, 10 Oct 2026
- Online privacy
- The online compressor states that images never leave your device. · caesium.app, 10 Oct 2026
- Preview and batch processing
- The desktop interface provides a real-time preview and processes multiple images at the same time. · saerasoft.com, 10 Oct 2026
- Purpose
- Caesium compresses digital pictures for storing, sending and sharing, and is aimed at photographers, bloggers, webmasters, businesses and casual users. · saerasoft.com, 10 Oct 2026
- Image resizing
- Yes · saerasoft.com, 20 Sept 2026
- Support
- The project README directs users to open an issue for troubleshooting or feature requests. · github.com, 10 Oct 2026
- Supported formats
- The online compressor allows JPG, PNG and WebP images. · caesium.app, 10 Oct 2026
- Windows support
- The current listed desktop version is v2.8.5 and supports Windows 10 build 1809 or later, with installer and portable downloads. · saerasoft.com, 10 Oct 2026
Where Caesium Image Compressor stands on Freedom251
- Image Compression Software#5 of 85