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About this LaTeX Formatter Online LaTeX Formatter

Working on a thesis, paper, or Beamer slides and your LaTeX got a bit messy? This LaTeX formatter uses Prettier with the unified-latex engine to reflow and indent your code so environments, sections, and math are easier to read—without changing the meaning of your document.

Why Use This LaTeX Formatter?

  • Uses Prettier with unified-latex under the hood for structure-aware LaTeX formatting
  • Works for typical .tex documents (articles, reports, theses, Beamer slides, notes, homework)
  • Normalizes indentation and line wrapping around environments, math, and macro arguments
  • Preserves comments and most intentional blank lines where possible
  • Paste LaTeX directly or drop a text file (up to ~5 MB)
  • Adjustable indent size and optional soft line-width guidance via wrap length
  • Client-first formatting in your browser, with a secure backend fallback when required

🔧 How to Format Your LaTeX Code Online for latex-formatter

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1. Paste or drop your LaTeX

Paste LaTeX code into the editor or drag-and-drop a text-based file (typically .tex). You can work on anything from a small snippet to a full document.

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2. Choose indentation & wrap length

Adjust the indent size (1–8 spaces) and optional wrap line length. A shorter wrap length produces narrower paragraphs; 0 disables automatic wrapping.

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3. Format & review the output

Run the formatter. If the LaTeX parses correctly, you get clean, re-indented code. If there’s a parsing issue, you’ll see an error so you can fix the source.

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4. Copy back to your editor

Copy the formatted LaTeX back into your editor or save it as a new file. Commit the cleaned version so co-authors and reviewers get a consistent layout.

Technical Details

Formatting Engine

This tool uses Prettier with the unified-latex plugin to parse LaTeX into a structured AST, then reprints it with normalized indentation and line breaks. It operates on the source code only and does not compile your document.

AspectBehavior
EnginePrettier + unified-latex formatter
InputPlain-text LaTeX (UTF-8)
OutputReformatted LaTeX source (UTF-8)
ExecutionClient-first (browser) with optional secure backend fallback
Timeout~25s safety timeout for heavy inputs or complex documents

Typical File Types

Any plain-text LaTeX is accepted; these are the most common:

TypeExamplesNotes
.tex documentsarticle, report, book, beamerMain LaTeX sources with preamble + body
Snippets\section{}, \begin{proof}…Great for cleaning smaller fragments used in docs or slides
Input fileschapter.tex, intro.texStandalone chapters or sections included via \input/\include

Formatting Behavior

The formatter focuses on layout and readability, not semantic validation.

AreaWhat it doesWhat it doesn’t do
IndentationIndents environments, nested structures, and certain macro bodies based on the configured indent size.Does not infer logical structure from custom macros beyond what unified-latex understands.
Line wrappingWraps long lines according to the wrap length (or leaves them as-is if set to 0).Does not guarantee perfect wrapping for every custom command or deeply nested macro.
CommentsPreserves comment lines and most inline comments in place.Does not interpret or refactor comment text.
MathKeeps math environments and inline math intact, adjusting surrounding indentation where appropriate.Does not verify mathematical correctness or LaTeX package usage.
PreambleFormats preamble sections like \usepackage, \newcommand, etc., with consistent spacing.Does not reorder packages or commands for compatibility.
Always recompile after reformatting to ensure your document still builds as expected.

Limits & Performance

The formatter is tuned for real-world documents used in academic and technical contexts.

InputLimitNotes
Text size (editor)≈ 2 MBHard limit enforced by the formatter to keep the browser responsive.
File uploads≈ 5 MBControlled by the UI file-size cap.
Formatting time< 1–2 s (typical)Varies with document complexity and browser performance.
Timeout behaviorFails gracefullyIf formatting exceeds the timeout, you get an error instead of a frozen tab.

Safety & Privacy

For standard usage, formatting runs directly in your browser using the Prettier + unified-latex adapter. In some environments, a secure backend formatter may be used as a fallback if the in-browser plugin is unavailable. In both cases, the LaTeX is treated as transient input: it is only used for formatting and not compiled or executed.

For highly confidential documents (e.g., embargoed papers, exams, proprietary reports), the safest option is still to run latexindent or other tools locally on your own machine.

Command-Line LaTeX Formatting Alternatives

Prefer local tools or want to integrate formatting into your build or CI pipeline? Here are common options.

Linux / 🍏 macOS

Format a LaTeX file in place with latexindent

latexindent -w main.tex

Rewrites main.tex with standardized indentation and layout.

Format all .tex files in a project

find . -name "*.tex" -print0 | xargs -0 latexindent -w

Applies latexindent to every LaTeX file in the current directory tree.

Windows (PowerShell)

Format all .tex files in the current folder

Get-ChildItem -Filter *.tex | ForEach-Object { latexindent -w $_.FullName }

Runs latexindent on each LaTeX file using PowerShell.

Use this online formatter for quick cleanups and snippets, then wire latexindent or editor integrations (VS Code, TeXstudio, Overleaf) into your daily workflow for automation.

Practical LaTeX Formatter Use Cases

Academic Papers & Theses

  • Clean up a messy draft before sending to your advisor or co-authors.
  • Keep long sections, proofs, and appendices consistently indented.
  • Normalize line lengths to make diffs in Git much easier to review.
% Before
\begin{proof}Let $G$ be a group with identity $e$...  \end{proof}

% After (formatted)
\begin{proof}
  Let $G$ be a group with identity $e$...
\end{proof}

Beamer Slides & Teaching Material

  • Tidy up slide decks with many frames and overlays.
  • Make example code blocks and math environments easier for TAs to maintain.
  • Prepare workshop or lecture notes in a consistent style.
\begin{frame}{Title}
  \begin{itemize}
    \item First point
    \item Second point
  \end{itemize}
\end{frame}

Reports, Docs & Dev-Oriented LaTeX

  • Format auto-generated LaTeX reports before committing.
  • Clean technical documentation with many code and verbatim blocks.
  • Standardize macros and environment layout across a team.
\begin{verbatim}
$ git commit -m "cleaned tex formatting"
\end{verbatim}

❓ Frequently Asked Questions

❓Does this tool compile my LaTeX or only reformat the source?

It only reformats the LaTeX source. The formatter parses the input into a structured representation and then prints it back with consistent indentation and line wrapping. It never runs latex, pdflatex, lualatex, or any other TeX engine.

🧪Will formatting change the meaning of my document?

The formatter is designed to change layout only—whitespace, line breaks, and indentation—while preserving commands, environments, and content. That said, LaTeX can be sensitive to certain line breaks in rare cases (e.g., fragile commands), so it’s always a good idea to recompile and skim the output after reformatting.

📏How big can my LaTeX file be?

For browser performance, the formatter limits the input to about 2 MB of text, and file uploads to roughly 5 MB. Larger theses or combined project files may require splitting or using local tools such as latexindent.

📦Does it understand custom macros and packages?

The formatter is layout-focused: it doesn’t need to know the semantics of every macro or package to indent and wrap text. However, very exotic or deeply nested custom syntax might not format perfectly. When in doubt, test on a copy of your document.

🔒Is my LaTeX document stored on the server?

The tool is designed as a client-first formatter: LaTeX is formatted in your browser using a local adapter where possible. In some setups, a secure backend may be used as a fallback, but documents are treated as transient formatting input, not long-term storage. For highly confidential work, prefer running latexindent or equivalent locally.

Pro Tips

Best Practice

Keep environments visually aligned: consistent indentation of \begin and \end blocks makes complex proofs and derivations much easier to navigate.

Best Practice

Run the formatter before committing to Git so co-authors review content changes instead of whitespace noise.

Best Practice

When working with fragile commands or custom macros, format a copy of your file first and recompile to ensure the layout change doesn’t affect the output.

Best Practice

Pair this online formatter with local latexindent or editor plugins for a fully automated LaTeX formatting workflow.

Additional Resources

LaTeX Project
Technical specification
Overleaf – Online LaTeX Editor
Documentation
latexindent Documentation
Documentation
LaTeX Formatting Quick Guide
Documentation

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