J2K Converter

Our fast and easy J2K image converter will help you avoid spending countless hours trying to figure out how to convert multiple .j2k files at once.

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Convert J2K on your PC

For quick and effortless J2K file handling on your PC, reaConverter offers powerful conversion tools with batch processing. Best of all, it works entirely offline — ensuring your sensitive data never leaves your computer.

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Do more with your images

Converting J2K images for use in a workflow? Touch up, transform, apply editing and effects to your images during conversion.

Our range of editing options includes such image processing actions as Resize, Rotate, Crop, Color Replace, Watermarks and more. Adjust actions include RGB, HLS, HSV, Brightness and Contrast. Auto-processing options are also available, such as auto-rotate and auto-crop.

Image editing tools

User Reviews

Average User Rating:
Last updated on November 01, 2025

"Your solution was buried deeper in search results than it should be. After struggling with unclear alternatives, I found your guides — finally, instructions that made sense for a first-time user like me. Excellent work!"

Richard E. Miller

Satisfied Customer

"I deal with hundreds of images daily, and reaConverter has been a lifesaver. The Watch Folders feature lets me automate file conversions without lifting a finger. I set up a folder for incoming files and it automatically resizes, renames, and converts them into the formats I need. It's like having a personal assistant!"

Sarah T.

Graphic Designer

"This program is incredibly simple and user-friendly, even beginners can use it with ease. It supports batch processing, works offline, and runs smoothly on my aging Acer Aspire laptop. Best of all, the output quality is outstanding!"

Kevin Harris

Happy User

"reaConverter is pure gold! Rock-solid performance with zero crashes. No internet needed—perfect for travel or low-connectivity work. The ultimate offline alternative to sketchy web converters. Plus, the desktop version keeps sensitive files secure since nothing ever gets uploaded to the cloud."

Malik T. Martin

Satisfied Customer

"Tried a few image tools before, but this one is by far the easiest. Drag, drop, convert — done in seconds. It saved me a ton of time when organizing my image folders."

Lisa K.

Happy User

"An efficient all-in-one solution for image conversion and light editing, designed for maximum user-friendliness."

Elena Anderson

Happy User

J2K images: Frequently Asked Questions

Can reaConverter open J2K files?

reaConverter fully supports the J2K image format – open, edit, and export J2K files to any other popular file format with ease.

How do I change J2K to another format?

reaConverter is a user-friendly tool for converting J2K files. Once installed on your computer, it allows you to convert all your .j2k files at once with just a few clicks. You can even convert j2k images directly from Windows Explorer using the right-click menu — fast and convenient.

Can I convert J2K online?

If you only want to convert a few J2K images, you are welcome to try our free online J2K converter.

How can I turn J2K files on my computer to another format?

The best way to convert J2K images on your PC is to get a quality piece of software, such as reaConverter. This software is extremely efficient in managing a wide range of batch files conversions, including conversion from J2K.

How can I automate J2K files conversion?

reaConverter supports all the essential automation features, such as right-click сonversion and Watch Folders, for the most efficient automated file conversion in any software of its kind.

Can I convert J2K files using scripts or the command-line interface?

reaConverter provides full access to all its features from the Windows command-line shell, including the command-line j2k converter.

What else can I do with reaConverter?

Change format settings Change DPI Copy metadata (EXIF, IPTC)Convert DICOM files Change photo size