✅ What is LaTeX Preview?

LaTeX preview is a system that automatically compiles and renders LaTeX mathematical expressions as images when you hover over them in your org-mode documents. This provides instant visual feedback for complex equations, matrices, and mathematical notation.

✅ Key Features

• Hover Preview: Rendered equations appear in tooltips when hovering over LaTeX code

• Multiple Syntax Styles: Support for both dollar-sign and backslash delimiters

• Dark Mode Aware: Automatically adjusts rendering for light and dark themes

• Smart Caching: Previously rendered equations are cached for instant display

• Document Settings: Use custom LaTeX packages and preambles

• Equation Numbering: Automatic numbering for equation environments

• Live PDF Preview: Full document preview with bidirectional sync

✅ Inline Math

Inline math appears within text paragraphs and uses the following delimiters:

✅ Display Math

Display math appears on its own line, centered and larger than inline math.

\[
\sum_{n=1}^{\infty} \frac{1}{n^2} = \frac{\pi^2}{6}
\]

Math Environments

LaTeX environments provide advanced layout and automatic numbering.

\begin{equation}
E = mc^2
\end{equation}

\begin{equation*}
F = ma
\end{equation*}

\begin{align}
x + y &= 5 \\
2x - y &= 1
\end{align}

\begin{align*}
\nabla \times \mathbf{E} &= -\frac{\partial \mathbf{B}}{\partial t} \\
\nabla \times \mathbf{H} &= \mathbf{J} + \frac{\partial \mathbf{D}}{\partial t}
\end{align*}

$$
A = \begin{pmatrix}
a_{11} & a_{12} & a_{13} \\
a_{21} & a_{22} & a_{23} \\
a_{31} & a_{32} & a_{33}
\end{pmatrix}
$$

Hover Preview

To preview any LaTeX math expression:

1. Position your cursor over the math expression

2. Wait briefly or hover with your mouse

3. A tooltip appears showing the rendered equation

The preview displays:

• The rendered equation as an image (SVG or PNG)

• Equation number (if applicable)

• The original LaTeX source code

Inline Previews (C-c C-x C-l)

C-c C-x C-l (scimax.org.latexPreview) draws math fragments as rendered equations in the editor, as org-latex-preview does in Emacs. The fragment's source is hidden and the equation is drawn in its place, in the editor's font size and a text color that suits the theme.

The section is the text from the heading above the cursor to the next heading of any level, or the text before the first heading. Toggling a region or section removes its previews if any are showing, and otherwise previews all its fragments, so pressing C-c C-x C-l repeatedly switches the equations on and off.

Clicking an equation shows its LaTeX source so you can edit it. When the cursor leaves the source, the equation is drawn again, re-rendered if you changed it. If the edit leaves no math there (say you deleted a delimiter), the preview is removed.

All the fragment types the hover preview knows are previewed: $...$, \(...\), $$...$$, \[...\] and math environments such as \begin{equation}. Numbered environments show their equation number.

Editing a previewed fragment:

• Moving the cursor into a preview shows its LaTeX source again; moving out shows the equation. A preview over several lines (an environment) shows its source while the cursor is on any of its lines.

• Edits made while the source is showing are re-rendered when the cursor leaves it. (Org instead removes the preview.) An edit that runs across the fragment's edge, such as replacing a selection that includes it, removes the preview.

• A fragment that fails to render gets a ⚠ after it; hover it for the LaTeX error.

Previewing when a file opens: #+STARTUP: latexpreview previews every fragment when the file is opened, and #+STARTUP: nolatexpreview turns that off for a file when scimax.latexPreview.startupWithPreview is on.

Differences from Emacs: VS Code cannot make a line taller, so an equation has to fit the lines its source takes up. A one-line fragment that is taller than a line (a big fraction or sum in \[...\]) is shrunk to the line height; give such equations their own lines in an environment to see them full size. An environment is drawn across its lines, so a three-line equation has three lines of room.

Inline Preview Settings

Changing the theme, the editor font size or these settings re-renders the previews.

Preview Caching

Rendered equations are cached in your VS Code global storage directory. The cache:

• Speeds up repeated hover previews

• Persists between VS Code sessions

• Automatically cleans up entries older than 7 days

• Stores separate versions for light and dark modes

Clearing the Cache

To clear all cached equation renders:

1. Open Command Palette (C-S-P / s-S-P)

2. Run: Scimax: Clear LaTeX Cache

To view cache statistics:

1. Open Command Palette

2. Run: Scimax: Show LaTeX Cache Statistics

This displays:

• Number of cached equations

• Total cache size on disk

Document-Level Configuration

Add LaTeX configuration at the top of your org file using #+LATEX_HEADER: keywords.

#+LATEX_HEADER: \usepackage{physics}
#+LATEX_HEADER: \usepackage{siunitx}
#+LATEX_HEADER: \usepackage{chemformula}

#+LATEX_HEADER: \newcommand{\RR}{\mathbb{R}}
#+LATEX_HEADER: \newcommand{\dd}[1]{\,\mathrm{d}#1}
#+LATEX_HEADER: \DeclareMathOperator{\Tr}{Tr}

$$\int_{\RR} f(x) \dd{x} = \Tr(A)$$

#+LATEX_HEADER: \usepackage{amsmath,amssymb,amsfonts}
#+LATEX_HEADER: \usepackage{mathtools}
#+LATEX_HEADER: \usepackage{bm}
#+LATEX_HEADER: \usepackage{physics}
#+LATEX_HEADER: \DeclareMathOperator{\sgn}{sgn}
#+LATEX_HEADER: \newcommand{\ve}[1]{\bm{#1}}

VS Code Settings

Configure global LaTeX preview behavior in your settings.

{
  "scimax.latexPreview.enabled": true
}

{
  "scimax.latexPreview.cacheEnabled": true
}

{
  "scimax.latexPreview.darkModeAware": true
}

Greek Letters

Math Operators

Relations and Operators

Arrows

Special Symbols

Delimiters

Accents and Decorations

Calculus

Derivative definition:

\[f'(x) = \lim_{h \to 0} \frac{f(x+h) - f(x)}{h}\]

Fundamental theorem of calculus:

\[\int_a^b f'(x) \,dx = f(b) - f(a)\]

Integration by parts:

\[\int u \,dv = uv - \int v \,du\]

Linear Algebra

Matrix multiplication:

$$

=

$$

Determinant:

\[\det(A) = \begin{vmatrix} a & b \\ c & d \end{vmatrix} = ad - bc\]

Eigenvalue equation:

\[A\mathbf{v} = \lambda\mathbf{v}\]

Physics

Schrödinger equation:

\[i\hbar \frac{\partial}{\partial t}\Psi(\mathbf{r},t) = \hat{H}\Psi(\mathbf{r},t)\]

Maxwell's equations:

Statistics

Normal distribution:

\[f(x) = \frac{1}{\sigma\sqrt{2\pi}} \exp\left(-\frac{(x-\mu)^2}{2\sigma^2}\right)\]

Bayes' theorem:

\[P(A|B) = \frac{P(B|A)P(A)}{P(B)}\]

Computer Science

Big-O notation:

\[T(n) = O(n\log n)\]

Recurrence relation:

\[T(n) = 2T\left(\frac{n}{2}\right) + O(n)\]

Common Problems and Solutions

{
  "scimax.latexPreview.darkModeAware": true
}

HTML Export

When exporting to HTML, LaTeX math is rendered using MathJax:

1. Inline math: $E mc^2$= → Renders with MathJax in browser

2. Display math: $$...$$ → Centered equation in HTML

3. Environments: \begin{align}...\end{align} → Properly formatted

The export includes MathJax CDN automatically, so equations render perfectly in web browsers.

LaTeX/PDF Export

When exporting to LaTeX or PDF:

1. Math expressions are passed through unchanged

2. #+LATEX_HEADER: settings are included in preamble

3. Equation numbering preserved

4. All environments work natively

Export and Preview Consistency

What you see in hover preview should match the exported output, but note:

• HTML export: Uses MathJax (may look slightly different from LaTeX preview)

• PDF export: Uses your LaTeX compiler (exact match with preview)

• Font differences: Preview uses default LaTeX fonts; exports may use custom fonts

Preview Commands

Live PDF Preview Commands

Markup Commands

Using Commands

1. Via Command Palette:

   • Press Cmd/C-S-P

   • Type "Scimax: Clear LaTeX Cache" (or any command name)

   • Press Enter

2. Via Keybinding:

   • For commands with keybindings, simply press the key combination

   • Example: C-c C-e l v opens live preview

Custom Keybindings

To add custom keybindings for commands without defaults:

1. Open Keyboard Shortcuts (`C-k C-s')

2. Search for the command (e.g., "Clear LaTeX Cache")

3. Click the + icon to add a keybinding

4. Press your desired key combination

Example keybindings.json:

[
  {
    "key": "ctrl+alt+l",
    "command": "scimax.clearLatexCache",
    "when": "editorLangId == 'org'"
  }
]

Multi-line Equations

Use \\ to break equations across multiple lines within display math:

\[ f(x) = a_0 + a_1 x + a_2 x^2 + \cdots \\ = \sum_{n=0}^{\infty} a_n x^n \]

Aligned Equations at Specific Points

Use & in align environments to specify alignment points:

The `&' symbols align vertically.

Cases and Piecewise Functions

Use the cases environment:

$$ f(x) = \begin{cases} x^2 & \text{if } x ≥ 0

\end{cases} $$

Chemical Formulas

With the chemformula package:

The reaction is \ch{2 H2 + O2 -> 2 H2O}.

or with `mhchem'

The reaction is \ce{2 H2 + O2 -> 2 H2O}.

Physics Notation

With the physics package:

#+LATEX_HEADER: \usepackage{physics}

$$\dv{f}{x} = \lim_{h \to 0} \frac{f(x+h) - f(x)}{h}$$

$$\grad V = \left(\pdv{V}{x}, \pdv{V}{y}, \pdv{V}{z}\right)$$

SI Units

With the siunitx package:

#+LATEX_HEADER: \usepackage{siunitx}

The speed is \SI{3e8}{\meter\per\second}.

Document Organization

1. Place all #+LATEX_HEADER: lines at the top of your org file, before the first heading

2. Group related packages together with comments

3. Define custom commands early for use throughout the document

Example:

#+TITLE: Research Notes
#+AUTHOR: Your Name
#+DATE: 2026-01-13

# Standard math packages
#+LATEX_HEADER: \usepackage{amsmath,amssymb,amsfonts}
#+LATEX_HEADER: \usepackage{mathtools}

# Physics
#+LATEX_HEADER: \usepackage{physics}

# Custom commands
#+LATEX_HEADER: \newcommand{\RR}{\mathbb{R}}
#+LATEX_HEADER: \newcommand{\dd}[1]{\,\mathrm{d}#1}

* First Section

Math Delimiters

Common Environments

Essential Commands

Keybindings

Settings

LaTeX Documentation

• LaTeX Math Wiki: https://en.wikibooks.org/wiki/LaTeX/Mathematics

• Comprehensive LaTeX Symbol List: http://tug.ctan.org/info/symbols/comprehensive/symbols-a4.pdf

• Detexify (draw symbols): https://detexify.kirelabs.org/classify.html

Package Documentation

• amsmath: https://ctan.org/pkg/amsmath

• physics: https://ctan.org/pkg/physics

• siunitx: https://ctan.org/pkg/siunitx

• chemformula: https://ctan.org/pkg/chemformula

Org-Mode Export

• Org-Mode Manual: https://orgmode.org/manual/

• LaTeX Export: https://orgmode.org/manual/LaTeX-Export.html

• Math Formatting: https://orgmode.org/manual/LaTeX-fragments.html

Scimax VS Code Documentation

• Export System

• Source Blocks

• Configuration