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Ozone — The J-Link Debugger and Performance Analyzer

  • Stand-alone graphical debugger
  • Debug output of any tool chain and IDE
  • C/C++ source level debugging and assembly instruction debugging
  • Debug information windows for any purpose: disassembly, memory, globals and locals, (live) watches, CPU and peripheral registers
  • Source editor to fix bugs immediately
  • High-speed programming of the application into the target
  • Direct use of J-Link built-in features (Unlimited Flash Breakpoints, Flash Download, Real Time Terminal, Instruction Trace)
  • Scriptable project files to set up everything automatically
  • New project wizard to ease the basic configuration of new projects

Ozone, the molecule and the debugger, are a powerful bug killer and efficiently protect you and your application.


Ozone is a full-featured graphical debugger for embedded applications. With Ozone it is possible to debug any embedded application on C/C++ source and assembly level. Ozone can load applications built with any tool chain / IDE or debug the target's resident application without any source. Ozone includes all well-known debug controls and information windows and makes use of the best performance of J-Link and J-Trace debug probes. The user interface is designed to be used intuitively and is fully configurable. All windows can be moved, re-sized and docked to fit the need of any developer.

Ozone is more than a simple debugger. Its various features, including trace, code profiling and code coverage analysis make it a powerful performance analyzer, which enable you to get full system insight, to track down inefficiencies and bugs, and to make your products even better.


Ozone can be used with virtually any ARM-based microcontroller.

With J-Link tightly integrated, all devices supported by J-Link can be used with Ozone.


Ozone focuses on debugging. No compiler or project window will distract your work. All debug windows can be moved, resized and docked, to provide you with the workspace you need.

With the source editor you can fix bugs immediately on detection.


Ozone is available on Windows, macOS, and Linux.

Similar look and feel on all platforms and fully portable projects enable efficient development on the operating system of your choice.


Ozone can be used with output of any tool chain / IDE. Freely select the compiler that best suits your project and always benefit from Ozone's capabilities.
Write your code in C or C++, Ozone visualizes your project sources and symbolic information.

Free Tool

Ozone can easily be downloaded and used free of charge with J-Link PLUS, ULTRA+, PRO, or J-Trace. You can also evaluate it for free.

Debug Capabilities

Ozone offers all well-known debug controls and information windows. Live watches, data graphs, and real-time terminal I/O further extend these capabilities.

System Analysis

With direct integration of J-Trace, Ozone enables CPU trace and offers different possibilities to analyze the run-time behavior and performance of your target system.

System Insight

Ozone includes RTOS aware debugging to provide information about the OS of your application - What are other tasks currently doing or how much stack does each task use.

Getting Started

First Run & Project Generation

When starting Ozone for the first time, the New Project Wizard will guide through the setup of the first project. Set your target device and the J-Link connection settings. Now select your application data file, which is usually the output (elf) file from your tool chain or IDE. Your first project is ready to run a debug session. You can save your project for further load and modify it, as it is a simple C-like script.

When starting Ozone again, a welcome dialog pops up, to open a recent project, or create a new one.


Debugging with Ozone can be controlled through the most common keyboard shortcuts or buttons from the toolbars, to be used intuitively.
To start debugging, a J-Link and the target have to be connected to the PC. Ozone can download the application code to the target, if there is a file selected.

A debug session is started with F5 or the green On/Off button from the toolbar.
After starting, the code is downloaded and the application is reset and runs to main(). The reset behavior can be changed via the System Variables.

Ozone features the most usable debug information windows to give full overview and control over the target application. The Source Viewer highlights the current line of execution and gives information about the application. The instructions to be executed can also be shown in the Disassembly. Ozone allows stepping on source level, as well as on instruction level. The Memory, Global, Local and Watched Data and the Registers Windows show information about the current state and content of the target. The data can also be written and changed from any of these windows. 

Ozone includes a Terminal which allows communication with the target in the most common ways. It can display SWO data, handle semihosting commands and show output and send input with SEGGER's Real Time Transfer (RTT) technology.

Ozone Licensing

Ozone can be used with J-Link PLUS, ULTRA+, PRO and J-Trace. With other J-Link models, Ozone can be used without restriction for evaluation purposes or after purchasing the J-Link RDI license, that includes the Ozone license. In evaluation mode, you will see the following screen each time a debug session is started:

Download & Installation

Download   Ozone - The J-Link Debugger for Windows, macOS or Linux

Download the setup and install Ozone with a few clicks. Multiple versions of Ozone can be installed on the same PC without any problems, as they can co-exist in different directories. Application settings are shared across the versions.

Ozone Media

Ozone The J-Link Debugger Introduction

Ozone The J-Link Debugger Features Part 1

Ozone The J-Link Debugger Features Part 2