Live Code File Formats

R2026b

MATLAB^® saves live scripts using the plain text live code file format (.m) by default. This format supports all live script features while enabling editing in external tools and integration with source control. You also can save live scripts using the binary live code file format (.mlx), which stores content in a binary structure designed for use in MATLAB.

Plain Text Live Code File Format (.m)

Since R2025a

The plain text live code file format is based on the standard MATLAB code file format (.m) and supports all live script features, including output, formatted text, interactive controls, and tasks.

Saving live scripts using the default plain text file format has several advantages:

• Open files in external editors — Open live scripts in any external text or code editor that supports plain text.

• Review file contents directly — File contents are readable as text, except for images and plots, which are saved as Base64 (ASCII-binary) strings in the plain text file.

• Use source control tools — Compare and merge live scripts using external source control tools.

Work with Plain Text Live Code Files

When you open a live script saved using the plain text file format, MATLAB displays the formatted content. For example, when you open the plain text live script fahrenheitconverter.m, MATLAB displays the title, formatted text, equations, interactive control, code, and output. Notice that in fahrenheitconverter.m, the line number for the first code line is 5. The reason is that in live scripts saved using the plain text file format, each line of text accounts for one or more code lines in the saved file.

To open the live script as a text file, right-click the file in the Files panel and select Open as Text. Editing a live script as a text file can prevent it from opening correctly if the markup structure becomes invalid.

Structure of Plain Text Live Code Files

The plain text live code file format uses custom markup to store code, text, images, and other live script content as plain text.

The markup appears in two places in the live script file, inline with the code and at the end of the file in an appendix:

• Inline markup — The plain text live code file format uses inline markup to store text items, such as formatted text, tables, equations, and hyperlinks. The format saves text lines as code comments, and each line of text can correspond to one or more code lines in the file. As a result, you cannot insert text between code statements that span multiple lines.

• Appendix — The plain text live code file format uses a single appendix at the end of the file to store content that does not fit inline, including:

  • Large amounts of data that cannot be stored inline

  • File information that is not associated with a specific line

For features that cannot be represented entirely with inline markup, the plain text live code file format uses reference IDs to link inline markup to corresponding data in the appendix. When merging live scripts, ensure that these reference IDs remain consistent between the inline content and the appendix.

For example, in the file fahrenheitconverter.m, lines 1 through 4 contain markup for a title and text line, and lines 11 through 24 contain the appendix. The appendix stores the current view of the live script and the data for the two outputs that the script generates. Line 7 contains inline markup for an output with the reference ID 3ffe5f06. The corresponding output data appears in the appendix on lines 19 through 21, where it uses the same reference ID.

Markup Details

In live scripts saved using the plain text live code file format, the Live Editor stores custom markup as comments. It uses a syntax based on Markdown for text content, such as formatted text, tables, images, and hyperlinks, and LaTeX commands for equations. Any line that does not begin with markup, including blank lines, is treated as code. Because blank lines are interpreted as empty code statements, do not insert them between markup lines. The only exception is a single blank line immediately before the %[appendix] marker, which separates code from the appendix.

This table provides more information about the custom markup used in the plain text live code file format (.m).

Markup Type	Markup Syntax
Section break	A line containing only %% creates a section break. Section breaks separate independently runnable code regions and control where outputs appear. Follow a section break with a %[text] ## Header line to give the section a heading. %% %[text] ## Data Processing data = load('measurements.mat');
Formatted text	Text is saved inline using the %[text] markup. Markup in the line specifies the formatting. Each %[text] line renders as a single paragraph. Enter each paragraph on a single %[text] line. Do not split a paragraph across multiple %[text] lines, as this creates separate paragraphs. The Live Editor automatically wraps long lines. %[text] This is basic text %[text] # This is a title %[text] ## This is a header %[text] This is **bold**, *italic*, `monospace`, and <u>underlined</u> %[text]{"align":"center"} This block of text is center aligned
List	Lists are saved inline using the %[text] markup. A backslash (\) at the end of a list item indicates the last item in the list. %[text] - This is the first item in a bulleted list %[text] - This is the last item in a bulleted list \ %[text] 1. This is the first item in a numbered list %[text] 2. This is the last item in a numbered list \
Table of contents	A table of contents is saved inline using the %[text:tableOfContents] markup. %[text:tableOfContents]{"heading": "Table of Contents"}
Code example	Code examples are saved inline using the %[text] markup. Plain code example (unhighlighted, monospaced text): %[text] ``` %[text] x = 1; %[text] y = "hello"; %[text] ``` MATLAB code example (syntax-highlighted, monospaced text): %[text] ```matlabCodeExample %[text] x = 1; %[text] y = "hello"; %[text] ```
Table	Tables are saved inline using the %[text:table] markup. %[text:table] %[text] | abc | def | %[text] | --- | --- | %[text] | 123 | 456 | %[text:table]
Image	Images are saved both inline and in the appendix. Syntax inline: %[text] this image:  Syntax in appendix: %[text:image:<imageid>] % data: { ... } %---
Hyperlink	Hyperlinks are saved inline using the %[text] markup. %[text] web page: [MathWorks Website](https://mathworks.com) %[text] file: [Duck Duck Go](/path/to/file.txt)
Internal link and anchor	Internal links allow navigation in a document. Create a named anchor at any text line, then link to it from elsewhere in the document. Anchor IDs must use only letters, digits, and underscores. Hyphens are not supported in IDs. %[text] %[text:anchor:my_section] ## Section Title %[text] See [Section Title](internal:my_section) for details.
Equation	Equations are saved as LaTeX commands inline using the %[text] markup. LaTeX commands start and end with the $ character. Inside $ ... $ equation delimiters: LaTeX commands use double backslashes: \\sin, \\frac, \\pi, \\sum. Markdown-significant characters use a single backslash: \_, \*, \[, \], \~, and \#. For a centered or display-style equation, use the {"align":"center"} attribute on the %[text] line. %[text] here is how to square four: $x = 4^2${"altText": "four squared"} %[text] and below is a large equation: %[text]{"align":"center"} $ X(k) = \\sum\_{n=0}^{N-1} x(n) e^{-j2\\pi kn/N} $
Output	Output is saved using the %[output] markup both inline and in the appendix. Syntax inline: %[output:<outputid>] Syntax in appendix: %[output:<outputid>] % data: { ... } %---
Control	Controls are saved using the %[control] markup both inline and in the appendix. The {"position":[start,end]} markup defines the start and end column positions of the value that is being replaced by the control in the code line. Syntax inline: %[control:<controltype>:<controlid>]{"position":[<start>,<end>]} For example: %[control:slider:67da]{"position":[6,8]} Syntax in appendix: %[control:<controltype>:<controlid>] % data: { ... } %--- For example: %[control:slider:67da] % data: {"defaultValue":40,"label":"Slider","max":100,"min":-100,"run":"Section","runOn":"ValueChanging","step":1} %--- Supported control types include button, checkbox, colorPicker, datePicker, dropdown, editfield, filebrowser, rangeslider, slider, spinner, and statebutton. For more information about controls, see Add Interactive Controls to Live Scripts.
Live Editor task	Live Editor tasks are saved using the %[task] markup both inline next to each task code line and in the appendix. Syntax inline: %[task:<taskid>] Syntax in appendix: %[task:<taskid>] % data: { ... } %---
Live script view	The current view of the live script is saved using the %[metadata] markup in the appendix. The "layout" field controls output placement: "inline" places outputs directly below the code that produces them, and "onright" places outputs in a panel to the right of the code. The optional "rightPanelPercent" field sets the width of the right panel. %[metadata:view] % data: {"layout":"inline","rightPanelPercent":40} %---

Source Control

Live scripts saved using the plain text file format can be compared and merged using external source control tools. For example, in GitHub^®, when you add a plain text live script to a repository, you can see the differences between revisions of the file.

Some external source control tools have file-size limitations that can prevent comparing live scripts saved using the plain text file format:

• GitLab^® and GitHub throw an error and do not display the differences in a file if the file size is too big.

• Perforce^® tries to display the differences but might become unresponsive if the file size is too big. To avoid Perforce becoming unresponsive, try disabling the Show Inline Differences option.

For the best results, try using GitHub Desktop or Visual Studio Code. You also can reduce file size by disabling the saving of output to your files. To disable saving output, go to the Home tab, and in the Environment section, click Settings. Select MATLAB > Editor/Debugger > Saving and in the Output Save Options section, clear Save output to file. Alternatively, clear all output before submitting your files to source control.

For more information, see the documentation for your source control tool.

Example: Plain Text Live Code File

This code shows the markup for a plain text live code file that includes headings, formatted text, equations, a table of contents, section breaks, a slider control, and output. To open a plain text live code file as plain text in the Editor, right-click the file in the Files panel and select Open as Text.

%[text] # Convert Fahrenheit to Celsius and Kelvin
%[text] This live script converts a value in degrees Fahrenheit to Celsius and Kelvin using the following equations:
%[text] - $\\degree C=\\left(\\degree F-32\\right)\\times \\frac{5}{9}${"editStyle":"visual"} 
%[text] - $\\degree K=\\left(\\degree F-32\\right)\\times \\frac{5}{9}+273\\ldotp 15${"editStyle":"visual"} \
F = -40; %[control:slider:67da]{"position":[5,8]}
%%
%[text] ## Convert Temperature
C = (F - 32) * 5/9;
K = C + 273.15;
%%
%[text] ## Display Results

fprintf("%.2f degrees Fahrenheit is %.2f degrees Celsius.",F,C); %[output:3ffe5f06]
fprintf("%.2f degrees Fahrenheit is %.2f Kelvin.",F,K); %[output:0875f432]

%[appendix]{"version":"1.0"}
%---
%[metadata:view]
%   data: {"layout":"inline","rightPanelPercent":20.2}
%---
%[control:slider:67da]
%   data: {"defaultValue":40,"label":"Slider","max":100,"min":-100,"run":"Section","runOn":"ValueChanging","step":1}
%---
%[output:3ffe5f06]
%   data: {"dataType":"text","outputData":{"text":"-40.00 degrees Fahrenheit is -40.00 degrees Celsius.","truncated":false}}
%---
%[output:0875f432]
%   data: {"dataType":"text","outputData":{"text":"-40.00 degrees Fahrenheit is 233.15 Kelvin.","truncated":false}}
%---

Binary Live Code File Format (.mlx)

The binary live code file format (.mlx) stores content using Open Packaging Conventions (OPC) technology, an extension of the ZIP file format. Code and formatted content are stored in an XML document, and output is stored separately using the Office Open XML (ECMA-376) format. For more information, see the Microsoft^® Open Packaging Conventions Fundamentals page and the ECMA Office Open XML File Formats (ECMA-376) page.

Source Control

Live scripts saved using the binary file format (.mlx) do not support standard text comparison. To compare these files, use the MATLAB Comparison Tool. When using source control, register the .mlx extension as a binary file. For more information, see Register Binary Files with SVN or Register Binary Files with Git.

Save Live Scripts Using Binary Format

By default, MATLAB saves live scripts using the plain text live code file format (.m). (since R2026b) To save a live script using the binary live code file format:

1. On the Live Editor tab, in the File section, select Save > Save As.

2. Select MATLAB Live Code File (*.mlx) as the file type.

3. Enter a filename. To avoid shadowing issues, use a different name if you are converting an existing file.

4. Click Save.

Convert Existing Code to Plain Text Live Scripts

You can convert an existing binary live script (.mlx) to a plain text live script (.m). You also can convert an existing MATLAB code file to a plain text live script. The conversion creates a copy of the file and leaves the original file untouched. The new file uses the plain text live code file format and supports all live script features. When converting a script, MATLAB converts any publishing markup to formatted content in the new live script.

1. Open the existing binary live script or MATLAB code file.

2. On the Editor or Live Editor tab, in the File section, select Save > Save As.

3. Select MATLAB Live Code File (*.m) as the file type.

4. Enter a filename. To avoid shadowing issues, use a different filename.

5. Click Save.

Alternatively, you can convert an existing script to a plain text live script by right-clicking the file's document tab in the Editor and selecting Open scriptName as Live Script.

When you convert an existing binary live script to a plain text live script, some text formatting might not look exactly the same. For example, formatting next to certain special characters or other formatted text might appear as markup, and leading white space is removed.

Change Default File Format

By default, MATLAB saves live scripts using the plain text live code file format (.m). (since R2026b)

To change the default live script file format, follow these steps:

1. On the Home tab, in the Environment section, click Settings.

2. Select MATLAB > Editor/Debugger.

3. In the Live script format section, set the Default live script file format setting to one of the available options.