Max Line Length for Visual Studio

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See and apply your project's preferred line length directly in Visual Studio. Max Line Length reads the effective max_line_length value from .editorconfig, displays a subtle ruler, and safely reflows supported content during Format Document and Format Selection.

This extension was inspired by the Visual Studio Developer Community feature request Support max_line_length in EditorConfig.

Why Max Line Length

Need	What the extension provides
Keep code readable	A clear visual boundary at the team's preferred line length
Apply the convention	Reflow supported content through Visual Studio's existing format commands
Share conventions	Configuration through the repository's existing .editorconfig file
Support mixed codebases	Per-file values resolved by Visual Studio from matching EditorConfig sections
Stay out of the way	No custom commands, options pages, or background scans

Getting started

Add max_line_length to a matching section in .editorconfig:

[*.{cs,vb}]
max_line_length = 120

Open a matching file in Visual Studio. The extension displays a vertical ruler immediately after column 120. Nested .editorconfig files and more specific sections work normally because Visual Studio resolves the effective setting for each document.

Change the value and save .editorconfig to update the convention. All open document rulers independently resolve their effective setting and move to the applicable column. Remove the property, set it to unset, or use an invalid value to hide the ruler and disable reflow.

Run Format Document or Format Selection to apply the configured limit. Plain-text documents wrap at the last whitespace before the limit and preserve indentation.

Executing the Format Document (Ctrl+K+D) command, the code is being reflowed.

Behavior

• Works with plain text, Markdown, C#, JavaScript, TypeScript, and C++ editors and uses the effective setting for each file.
• Honors indent_size, indent_style, and tab_width when calculating visual columns.
• Follows editor scrolling, zoom, font, and viewport changes.
• Stays hidden in diff views.
• Uses the editor foreground color with reduced opacity so it fits light, dark, and high-contrast themes.
• Groups built-in formatting and reflow into a single undo transaction.
• Restricts Format Selection reflow to complete selected lines or complete C# syntax constructs.
• Leaves C# string and character literals unchanged because inserting raw newlines would produce invalid or semantically different code.
• Reflows only comments in JavaScript, TypeScript, and C++; expressions remain unchanged because automatic semicolon insertion, templates, preprocessors, and raw strings require language-specific transformations.
• Reflows ordinary Markdown paragraphs but leaves front matter, headings, lists, block quotes, tables, fenced or indented code, inline code, HTML, and hard line breaks unchanged.
• Does not intercept mouse or keyboard input.

Profiling

The ProcessesRepresentativeFormattingWorkload test exercises the plain-text, Markdown, classified-comment, and C# reflow engines with representative document sizes. Filter on Category=Profiling when targeting this workload with a CPU or allocation profiler. It isolates the formatting algorithms; profile an experimental Visual Studio instance to measure editor, command-routing, and adornment overhead.

Get involved

Found a bug or have an idea? Open an issue or pull request on the GitHub repository.