ConUtil Compressor

ConUtil Compressor is a browser-based image compression tool that runs entirely on your machine. Images never leave your computer, which solves the privacy concern that comes with uploading files to random compression services. The creator built it out of frustration with existing tools that pester users with popups, demand subscriptions, or quietly ship images to servers overseas.

The tool handles JPEG, PNG, WebP, and other common formats. Users drag images into the browser window, pick compression settings, and download the results directly. There is no account to create, no email to enter, and no recurring payment to manage. It just works.

Bulk processing is a core feature. Instead of compressing one image at a time, users can drop an entire folder worth of files and process them in a single batch. The interface shows compression statistics as files process, including total savings, processing time, and compression ratios for each image. When finished, everything exports as a ZIP file for easy handling.

Quality control is adjustable. Users can pick a percentage quality level or choose from presets like Best, HD, 2K, 4K, Light, Balanced, or Web Optimized. There is also an optional resize function for situations where dimensions need to change alongside compression. This flexibility covers everything from archiving full-resolution photos to preparing thumbnails for a website.

Because processing happens locally in the browser, performance depends on the user's hardware rather than server capacity. Modern machines handle batches quickly, but older devices or very large files may take longer. The tradeoff is privacy and control, which matters more to some users than raw speed.

ConUtil Compressor is completely free and open source under the MIT license. The code is on GitHub, so anyone can audit it, contribute fixes, or fork it for their own purposes. There is no premium tier lurking behind the free version, no ads, and no telemetry phoning home.

The tool fits anyone who needs to compress images regularly and does not want to deal with the friction of cloud services. Developers, designers, bloggers, and small teams who work with images daily will find it practical. The local-first approach also makes it useful for handling sensitive visuals that should not leave the network.