LLDB (Low-Level Debugger) is the default debugger provided by Apple for debugging iOS, macOS, watchOS, and tvOS applications. LLDB is a powerful command-line debugger that allows developers to inspect and manipulate the runtime state of their applications, set breakpoints, analyze variables, and diagnose issues during development and testing.


Key features and capabilities of LLDB include:


  • Interactive Debugging: LLDB provides an interactive debugging environment where developers can enter debugger commands, evaluate expressions, and inspect program state dynamically during runtime.
  • Breakpoint Management: LLDB allows developers to set breakpoints at specific lines of code, functions, or memory addresses to pause execution and examine the program’s state. Breakpoints can be conditional, meaning they are triggered only when specific conditions are met, and can be configured to perform actions such as logging messages or executing debugger commands.
  • Expression Evaluation: LLDB enables developers to evaluate expressions, variables, and data structures dynamically using the debugger console. Developers can inspect object properties, call methods, and manipulate data structures to diagnose issues and understand program behavior.
  • Symbolic Debugging: LLDB provides symbolic debugging capabilities, allowing developers to debug optimized and stripped binaries by using symbol tables, debug information, and source maps generated during the build process. Symbolic debugging enables developers to debug code at the source level, even in release builds and third-party libraries.
  • Scripting Support: LLDB supports scripting using Python, allowing developers to automate debugging tasks, write custom debugger commands, and extend LLDB’s functionality. Python scripts can interact with LLDB’s Python API to perform complex debugging operations and analyze program state programmatically.
  • Integration with Xcode: LLDB is tightly integrated with Xcode, Apple’s integrated development environment (IDE) for iOS and macOS development. Developers can use LLDB directly within Xcode’s debugging environment to debug iOS apps, analyze crashes, and diagnose issues using Xcode’s visual debugger interface and debugging tools.


LLDB is a versatile and powerful debugger that provides developers with advanced debugging capabilities for diagnosing issues, analyzing program behavior, and optimizing the performance and reliability of their iOS applications.

Previously at
Flag Argentina
time icon
Skilled iOS Engineer with extensive experience developing cutting-edge mobile solutions. Over 7 years in iOS development.