Script Debugger 8

You want your computer systems to be simple, reliable and automatic. Script Debugger is the integrated development environment that makes that happen by making your AppleScript coding easier, faster, and more transparent. And now Script Debugger runs natively on M1 Macs, with full support for universal applets, Dark Mode, and themes.


Before you begin scripting, discover the information and commands that your applications offer. Use the Explorer to experiment with applications, explore their data and manipulate it to see how the application responds. When you create and debug your script, the Explorer remains available and continues to show data information as you work.


Maximize your productivity and write scripts easily and quickly with Script Debugger’s powerful and flexible code creation features. Insert tell blocks for applications and objects or properties. Script Debugger helps you by intelligently inserting a broad range of commonly-used code segments. These features are specifically designed for the peculiarities of the AppleScript language. They let you easily navigate large scripts, automatically enter “end” lines and closing delimiters, and more.


As you create, test your scripts to make sure they behave as expected. Script Debugger can run a script in an analytical mode that tracks your variables and their values, making it easy to isolate and fix specific problems when things go wrong. Watch your script as it runs, line by line, viewing the values of variables at every stage of the script’s execution. Use breakpoints to pause your code at key points. With Script Debugger, you never have to guess about what is happening as your script runs.


Easily package scripts for your clients and colleagues. Script Debugger checks for common errors when packaging scripts, and it makes distributing scripts to others amazingly simple. Should your script contain sensitive or private information, you can export it in “run only” form to prevent others from accessing the code. Script Debugger anticipates problems by telling you instantly what applications, scripting additions, libraries and frameworks are needed in order to run your script successfully.

Why AppleScript

First introduced by Apple in 1992, AppleScript is a venerable and proven scripting language for automating tasks on the Macintosh. It uses terminology that is similar to common English words, and it is relatively easy to learn in comparison to other scripting languages. But it is also an object-oriented language that is fully capable of handling complex programming tasks when necessary. AppleScript creates script files that can control your computer and its various applications. It can be used to automate repetitive and error-prone manual tasks, saving both time and money.  For example, it can automatically retrieve files from remote servers or schedule and execute important updates. Its broad range of possible uses makes it a powerful tool for both individuals and businesses in search of optimized workflows.

What Is Script Debugger?

Script Debugger is an integrated development environment focused entirely on AppleScript. This focus allows it to deliver a suite of tools that make AppleScript development amazingly productive. You can use it to write and edit code, analyze target applications, debug scripts, and more.

Script Debugger has been making AppleScript better for over 25 years!  Script Debugger 8 continues the tradition with support for Apple M1 Macs and macOS Big Sur.

Script Debugger’s features include:

Dictionary Explorer

The Dictionary Explorer lets you see directly into the live data within any scriptable application. Unlike Apple’s Script Editor, you don’t have to imagine how to convert a written description of an application’s scripting interface into code. Script Debugger shows it to you visually and lets you interact with the application without having to write a line of AppleScript.

Step-Wise Debugging

This is the best way to see what your script is doing and to find bugs quickly. Execute scripts line-by-line to see exactly how they are executing. Set breakpoints to pause a script at key points. No more Caveman Debugging with AppleScript `log` statements. Script Debugger shows you the result of each and every statement as you go and the value of every variable in your script. There is no better way to see exactly what your code is doing.

Powerful Code Completion

Script Debugger provides an amazingly helpful set of code completion tools. They include completion of variable names in your script, AppleScript and Scripting Addition commands, as well as application commands and names. Script Debugger also provides completions for AppleScriptObjC handlers which are tedious and error prone to type by handle.

Split-Pane Editing & Code Folding

Work with long scripts easily. Split-pane editing allows you to view two or more sections of your script at the same time. Code Folding lets you collapse portions of your code to help you focus on your work.

See All Your Variables

See the values held in your script’s variables as your script executes. You can also see the value each variable holds in different ways. For example, if the value of a variable is a file reference, you can see the corresponding AppleScript source code, or the file’s name, path and icon, and even its contents via QuickLook. Script Debugger’s ability to show how your script operates and the data it uses will be a revelation.

Tabbed Windows

Organize your work by opening multiple script documents at once and organizing them into separate windows or multiple tabs within a single window.

Dark Mode & Text Themes

Script Debugger 8 fully supports Dark Mode and introduces the notion of themes to manage the presentation of scripts in light and dark mode.


Script Debugger provides virtually endless opportunities for customization. Create your own script templates. Generate clippings to insert commonly used blocks of code. Clippings can employ markup to insert parameters and speed editing. Create AppleScript scripts to automate repetitive tasks. Assign keyboard shortcuts to your clippings, scripts and any Script Debugger menu command.

AppleScriptObjC Value Viewing

If you use AppleScriptObjC, Script Debugger shows you the details of the Objective-C values your script is using. Unlike Apple’s Script Editor, where you see «class ocid» id «data optr0000000080100F0000600000» and wonder what this value might be, Script Debugger identifies that is an array with five elements, for example, and shows the value of each array element. The content of scalar value types such as NSString, NSAttributedString, NSNumber, NSValue, NSImage, NSColor, NSDate and NSURL are shown directly.

Open Quickly

Script Debugger can easily find the script you want to work with. The Open Quickly command lets you find scripts targeting specific applications, documents or even scripts containing a particular variable or handler name. You don’t even have to know the full name of the thing you are looking for. Start typing and Script Debugger will offer you the most relevant search hits it can find.

Script Debugger Has Your Back

Script Debugger offers facilities to find common scripting and deployment errors.  For instance, the Leaks feature detects when your script opens and does not close a file, or when a database transaction begins and is not finished.  Script Debugger watches for common errors like saving a script with an idle handler, but without enabling the Stay Open setting.

Code Generation

Use the Dictionary Explorer to find the application objects you need, and then use drag & drop to add AppleScript code to your script. Combine this with all of Script Debugger’s other code building tools, including the Tell Block builder, to save enormous amounts of time and avoid errors.

Apple Silicon (M1)

Script Debugger runs natively on Apple Silicon Macs and generates universal applets when running under macOS Big Sur.

Enhanced Applets

Script Debugger offers a new way of deploying AppleScripts as standalone applications with an improved interface for your users, support for automatic software updates via Sparkle and much more. If you are creating AppleScript droplets, Script Debugger’s enhanced applets provide a drop target window where users can drag & drop files or use Spotlight searching to find the files they want to process.

Code Signing & Notarizing

When the time comes to share your work with others, Script Debugger integrates with our free SD Notary application to code-sign and notarize the script applications you create.

Mini Debugger

Script Debugger’s mini debugger window floats above the windows of all applications on your Mac.  Use this when you don’t want the layering of windows to change as you debug your script.

Script Debugger Lite

If you don’t need all of Script Debugger’s advanced features, but want something better than Apple’s Script Editor, we offer a LITE version of Script Debugger.

Support forum

Late Night Software provides a public support forum where anyone can come, customer or not, for help with Script Debugger or AppleScript.  Out forum aims to very low noise and welcoming.

Who Is Script Debugger For?

Script Debugger is for any individual or organization wanting to automate routine tasks on the Macintosh.

The possibilities are vast. Almost any routine software function that you or your staff carry out manually can be automated to save time and money and reduce errors. Script Debugger makes the coding process faster and frees you up to think creatively about new ways to use AppleScript to make your life easier and more productive.

New In Script Debugger 8

Script Debugger 8.0 introduces the following major new features:

Big Sur & Apple M1 Support

Script Debugger 8 fully embraces macOS Big Sur and Apple M1 Macs. Script Debugger’s appearance has been updated to fit nicely into macOS Big Sur. Script Debugger 8 runs natively on Apple’s new M1 Macs, and generates universal Intel/ARM applications when running under macOS Big Sur, regardless of platform.

Dark Mode

At long last, Script Debugger 8 supports Dark Mode. This has been the most requested Script Debugger change since Apple introduced Dark Mode and it’s finally here!


To go along with Dark Mode support, Script Debugger 8 provides user configurable and switchable themes. Themes can automatically handle transitions between Light Mode and Dark Mode, and you can change them manually. You can create your own custom themes to easily switch script formatting depending on the task at hand.

Library Improvements

Viewing script library documentation has been made much easier with the introduction of a Libraries section within Script Debugger’s dictionary window. Script Debugger is able to automatically discover libraries in more locations. You can now add frequently used libraries to your Favorites list.

Revised Applet Building, Code-signing & Notarizing

Apple’s improvements to security in macOS Mojave, Catalina and now Big Sur required a reimagining of Script Debugger’s ability to create stand-alone script applications. Script Debugger 8 offers vastly expanded options for generating standalone applications, along with the ability to code-sign and notarize applications.

Line Editing

Script Debugger 8 introduces a suite of new editing commands that operate on lines: Move Up, Move Down, Insert Before, Insert After, Cut, Copy, Delete and Duplicate. Like all menu commands in Script Debugger, you can assign your own keyboard shortcuts to these commands. This change makes script editing even faster, especially when coming from other editors which offer these commands.

No More Debug Documents

Previous versions of Script Debugger saved scripts with debugging enabled in a special format to facilitate something we called external debugging, which allowed scripts to be debugged while running within other applications. While external debugging was useful in some situations, users were often caught out when distributing scripts with debugging enabled because the file format required Script Debugger be present.

Security changes introduced in macOS Mojave and later rendered Script Debugger’s external debugging feature inoperable. For Script Debugger 8 we’ve removed external debugging and now all scripts are saved in the standard script format, guaranteeing scripts can be easily shared.

Direct Export

Script Debugger 8 introduces a new workflow for exporting run-only applications. By storing all related settings in documents of any script format, exporting becomes a one-click process, while new destination options offer greater convenience in organizing and tracking changes as scripts are updated.

Miscellaneous Improvements

Script Debugger 8 includes heaps of improvements to existing features.



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