4K Image Compressor 26.0: What's New?

Version 26.0.0 of 4K Image Compressor brings a more polished interface, better support for Linux users with its freshly added dark theme, and a fix for one of the more persistent file-handling headaches reported by our HEIC and HEIF users. Here's a closer look at what changed.

A Cleaner, More Consistent Look

The most visible change in this release is a refresh of the Control Panel and the News section. Buttons throughout both areas have been redesigned to match the app's updated visual language, giving the interface a more cohesive and modern feel. It's not a dramatic overhaul, but the kind of detail-level polish that makes the app feel more consistent every time you open it, whether you're adjusting compression settings or catching up on the latest updates from the News tab.

Dark Theme Arrives on Ubuntu

Linux users get a meaningful upgrade in this version: 4K Image Compressor now supports dark theme on Ubuntu. Rather than requiring a manual toggle, the app reads your system's appearance settings and adapts automatically, so the interface stays in sync with however you've configured your desktop.

HEIC & HEIF Files Now Work as Expected

That, perhaps, is the most practical fix in this release addresses an issue where opening HEIC or HEIF files could trigger an "unsupported input format" error, even though these are common formats produced by default on many iPhones and other modern devices. That error is now resolved, and both formats are handled correctly.

Many Improvements Under the Hood

Beyond the headline changes, this release also includes a number of smaller UI/UX and stability improvements. None of these are big enough to warrant their own section, but together they contribute to a smoother, more reliable experience across the app.

As always, the update is free for existing users of 4K Image Compressor. Make sure you update your current version to 26.0.0 on our website or inside 4K Image Compressor.