11 min read

Source: Roblox Creator Hub · CC BY 4.0 · View source · Code samples: MIT Imported 2026-10-03. Formatting adapted for this site.

Debugging

Studio offers many debugging tools and workflows commonly found in Integrated Development Environments (IDEs). These help you inspect and resolve errors in scripts as they run.

Breakpoint debugging

Breakpoints are checkpoints that pause or "break" the execution of your scripts at specific lines. You can use the pauses to inspect and debug your game, watch variables, and inspect the call stack. Breakpoints are one of the most effective ways to debug functions, so they're one of the most important debugging tools.

Management

In the Script Editor, you can insert several types of breakpoints and edit the configuration of a breakpoint at any time, including during playtest sessions. If you edit breakpoints during a playtest session, the edits persist even after you finish it. You can also edit a breakpoint that's actively pausing your playtest session, but changes don't apply until the next playtest session.

Insert

Breakpoints take multiple variations and can be inserted at any line of executable code as follows:

Standard

To insert a standard breakpoint at a line of code, click in the gutter directly to the right of its line number. Alternatively, right‑click in the gutter and select Insert Breakpoint. The breakpoint icon appears as a red circle.

Standard breakpoint shown in the script gutter

Conditional

A conditional breakpoint pauses your script only if a specified condition is true, so it's useful for debugging how functions execute when certain variables have certain values or if you want to break only on certain executions in a loop.

To insert a conditional breakpoint, right‑click in the gutter and select Insert Conditional Breakpoint. In the popup window that appears, enter the desired condition, such as var == 10 , then click Save. The conditional breakpoint icon appears as a circled = sign.

Conditional breakpoint shown in the script gutter

Logpoint

A logpoint is a special breakpoint that logs messages to the Output window without pausing the script, making it useful for debugging the values of the variables before the line executes.

To insert a logpoint, right‑click in the gutter and select Insert Logpoint. In the popup window that appears, enter the desired log message, such as "The value of var:", var , then click Save. The logpoint icon appears as a red diamond.

Logpoint shown in the script gutter

Temporary

A temporary breakpoint offers the same options as other breakpoint types, except that it automatically removes itself after the first playtest session. This makes it ideal for quickly testing variable values or functionality without needing to disable or delete the breakpoint afterward.

To insert a temporary breakpoint, right‑click in the gutter and select Insert Temporary Breakpoint. It initially appears as red circle and then you can edit its options to specify the behavior.

Standard breakpoint shown in the script gutter

Disable

To temporarily disable a breakpoint without deleting it, use any of the following workflows:

A disabled breakpoint appears as a hollow version of its enabled icon, for example a hollow circle for a disabled standard breakpoint, or a hollow diamond for a disabled logpoint.

	<img alt="Disabled standard breakpoint shown in the script gutter" src="https://prod.docsiteassets.roblox.com/assets/studio/debugging/Gutter-Breakpoint-Disabled.png" width="400" />

Disabled standard breakpoint

	<img alt="Disabled logpoint shown in the script gutter" src="https://prod.docsiteassets.roblox.com/assets/studio/debugging/Gutter-Breakpoint-Logpoint-Disabled.png" width="400" />

Disabled logpoint

Delete

To delete a breakpoint, middle-click its icon or right‑click its icon and select Delete Breakpoint.

Note

Deleting a breakpoint deletes its Condition and Log Message. If you want to keep this information for future debugging, disable the breakpoint instead.

Edit

You can edit the configuration of a breakpoint at any time, including during playtest sessions. If you edit breakpoints during a playtest session, the edits persist even after you finish it. You can also edit a breakpoint that's actively pausing your playtest session, but changes don't apply until the next playtest session.

To edit a breakpoint:

  1. Right-click the breakpoint icon and select Edit Breakpoint.

  2. In the Edit Breakpoint window, configure the breakpoint as desired. You can mix these configurations together to best suit your debugging needs.

    Option Description
    **Condition** An optional expression that determines whether the breakpoint activates. If the condition is empty, the breakpoint always activates. If the condition exists, the breakpoint becomes a [conditional breakpoint](#insert) and activates only if the condition is true. For example, if you want the breakpoint to activate only if the variable `var` equals `10`, set the condition to

var == 10 .

Log Message An expression that prints to the Output window when the breakpoint is hit. The format of the log message is the same as that of a LuaGlobals.print() statement. For example, set the log message as "The value of var:", var to output the same message as print("The value of var:", var) . Continue Execution Determines whether the breakpoint pauses the script if it activates. This option is disabled by default unless the inserted breakpoint is a logpoint. Remove Breakpoint on Hit If checked, the breakpoint automatically removes itself after the first playtest session, effectively making it a temporary breakpoint. Trigger At The context of a breakpoint determines whether it should activate on the Client (client‑side scripts), Server (server‑side scripts), or Edit (debugging plugin scripts). If you choose Custom Context, the window indicates the current trigger contexts.

Workflow

The typical workflow for breakpoint debugging is as follows:

  1. Open the script you'd like to debug and insert breakpoints on the lines of codes that you want to examine.

  2. From Studio's mezzanine, initiate a playtest to begin debugging.

    Test option in the testing modes dropdown of Studio's mezzanine.
  3. When the script hits a breakpoint, the playtest session pauses unless that breakpoint is configured to continue execution. A yellow arrow over the breakpoint indicates which line of code executes next.

    Active breakpoint in the debugger showing yellow arrow
  4. As the script pauses, inspect the Breakpoints window, Watch window, Call Stack window, Output window, and Script Editor to find information about variable values and function executions.

  5. To continue executing code after hitting a breakpoint, click Resume Scripts in the mezzanine.

    Resume Scripts button indicated in Studio's mezzanine

    You can also execute code one line at a time with the stepping buttons in the mezzanine:

    Breakpoint stepping buttons indicated in Studio's mezzanine
    Action Shortcut Description
    **Step Into** F11 The **Step Into** button moves the debugger into the code of the function on the current line. If there is no function on the current line, the debugger moves to the next line.
    **Step Over** F10 The **Step Over** button moves the debugger to the next line of code, **not** moving into functions.
    **Step Out** ShiftF11 The **Step Out** button moves the debugger out of the current function and to the next line of code after the function call. If the current line isn't inside a function, the debugger moves to the next line.
  6. When you're finished debugging the current session, click the Stop button.

    Stop button indicated in Studio's mezzanine.

Monitoring

Studio includes multiple windows and tools to monitor variable values and function executions while debugging. With this information, you can find the root cause of most problems in your scripts.

Breakpoints button indicated in Studio's toolbar

Breakpoints

The Breakpoints window is a unified view that shows all breakpoints within all scripts. To open it, click Breakpoints from Studio's Script tab toolbar, or navigate to the Window ⟩ Debug menu and toggle on Breakpoints.

In the window, the Script and Line columns always display, and you can toggle on/off other configuration columns through the ⋮ menu in the upper‑right corner. Within the Script column, right‑click any breakpoint to reveal an options menu to edit, disable/enable, delete, or jump to the breakpoint's line within the script.

Breakpoints window in Studio

While in a debugging session, the furthest left column shows (x3) which indicates the multiple contexts (Client, Server, Edit) for the breakpoint. By expanding any breakpoint's branch, you can then click the icon next to a specific context to disable/enable it for that context, such as disabling a breakpoint only in the Client context while keeping it enabled in the Server context.

Breakpoint expanded to show contexts

Call Stack

The Call Stack window, accessible from Studio's Script tab toolbar or the Window ⟩ Debug menu, shows which line of code is going to execute next when the debugger reaches a breakpoint. If you call functions from inside other functions, it indicates which lines those functions were called from, letting you confirm whether the actual call flow matches the expected flow.

Call stack flow in a scriptCall stack flow in the Call Stack window

As the script pauses at breakpoints, use the stepping buttons in the mezzanine to step into, over, or out of a function/line as outlined in workflow.

Breakpoint stepping buttons indicated in Studio's mezzanine

Watch

The Watch window, accessible from Studio's Script tab toolbar or the Window ⟩ Debug menu, lets you actively watch variable and expression values as you step through breakpoints.

Variables

The Variables tab shows information about the current variables in scope, filterable by clicking the All Scopes button in the window's upper bar. Expanding a branch shows the members of that variable or instance and their values. You can also watch any variable by double‑click highlighting it in the Script Editor, right‑clicking, and selecting Add Watch from the popup menu.

Variables to watch inside a scriptVariables information in the Watch window

My Watches

The My Watches tab shows the value of variables or expressions that you define. To watch a specific expression, click an empty row in the Expression column and type the expression into it. This allows you to check any expression value without monitoring individual variables in the Variables tab or adding LuaGlobals.print() statements in the script to check expression values.

Variables to watch inside a scriptExpression entered into Watch window for analysis

Script Editor

The debugger is integrated with the Script Editor. When your game pauses at a breakpoint in a script, you can hover your mouse over the name of a variable to see its value. For example, you can see the composition of a table and its contained keys/values.

Mouseover a variable in Script Editor to show value

Additional debugging tools

In addition to the debugger, Studio offers additional debugging tools for you to fix problems and bugs in your game.

Command Bar

The Command Bar allows you to run Luau commands while the game is running. It is available in Studio from the Window ⟩ Script menu and in the Developer Console.

Developer Console

The Developer Console provides a wide array of details including client and server output, memory usage, network performance, and more. To open console while testing or playing a game, type /console into the chat or press F9.

Log files

When a script prints or errors in Studio or the player app, the app records the message in a log file in the local file system. These files are located in different places depending on the operating system.

Windows

To access log files on Windows:

  1. Open File Explorer.
  2. Navigate to the %LOCALAPPDATA%\Roblox\logs directory.
  3. Double-click a log to open it. Logs with the same XXXXX value are from the same Studio session.

Mac

To access log files on Mac:

  1. Open Finder.
  2. In the menu bar, select Go ⟩ Go to Folder....
  3. In the dialog, enter ~/Library/Logs/Roblox.
  4. Double-click the result to navigate to the Roblox logs directory.
  5. Inside the directory, double-click a log to open it.

iOS

You can collect iOS logs using a Mac or using an iOS device.

Mac

To access iOS log files on a Mac:

  1. Connect the iOS device to a Mac.
  2. Open Finder.
  3. Navigate to Utilities and open the Console application.
  4. To populate real-time logs in the Console application, select the iOS device from the sidebar, click the Start button, and reproduce the issue on the iOS device.
  5. To populate archived logs in the Console application, run sudo log collect --device-name "[iOS Device Name]" in the Terminal. Make sure there are no apostrophes in the device's name or you might get an error when running the command.

Device

To access iOS log files on an iOS device:

  1. Press and hold both volume buttons and the top or side button on the iOS device for 1 to 1.5 seconds to start the sysdiagnose program. This process might take up to 10 minutes to finish.
  2. Navigate to Settings ⟩ Privacy & Security ⟩ Analytics & Improvements ⟩ Analytics Data to access the log files.
  3. Tap on the a log file to open it.

Android

To access log files on Android:

  1. Navigate to Settings ⟩ System ⟩ Developer options.
  2. Toggle Developer options on.
  3. On a computer, download and install Android Studio.
  4. In Android Studio, click Logcat.
  5. Connect the Android device to the computer to automatically populate Logcat with logs.