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How to Bold in LaTeX

To bold text in LaTeX, write \textbf{your text}. Inside a formula use \mathbf{x} for upright bold letters (vectors, matrices) and \boldsymbol{\alpha} — or \bm{\alpha} with the bm package — for bold italic letters and bold Greek symbols.

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Bold commands

  • \textbf{bold text}
    bold text

    Bold text in a paragraph (works inside math too).

  • {\bfseries bold text}
    Text mode, no math preview

    Switch to bold until the closing brace; handy for whole paragraphs or table cells.

  • \mathbf{v}
    v

    Upright bold letters and digits in math, e.g. vectors.

  • \boldsymbol{\alpha}
    α

    Bold version of any math symbol, keeps italics; from amsmath.

  • \bm{\alpha}
    Text mode, no math preview

    Same idea as \boldsymbol, usually better spacing; needs \usepackage{bm}.

  • \textbf{\textit{text}}
    text

    Bold and italic together.

  • \pmb{x}
    x x

    "Poor man's bold": overprinted, for symbols that have no bold font.

Try it live

Change the formula and the preview redraws as you type. Copy the LaTeX, download a PNG or SVG, copy it for Word, or use Edit here on any example below to load it.

Templates

Bold examples

Each result below is drawn from the LaTeX under it. Copy the code, edit it on this page, or open it in the full editor.

  • Bold vector

    v = ( v 1 , v 2 , v 3 )
    LaTeX
    \mathbf{v} = (v_1, v_2, v_3)
    Edit hereOpen in editor

  • Bold Greek letters

    θ = ( θ 1 , … , θ n )
    LaTeX
    \boldsymbol{\theta} = (\theta_1, \dots, \theta_n)

    \mathbf{\theta} would leave the θ plain: \mathbf only affects Latin letters and digits.

    Edit hereOpen in editor

  • Upright vs italic bold

    x vs x
    LaTeX
    \mathbf{x} \quad \text{vs} \quad \boldsymbol{x}

    \mathbf gives upright bold, \boldsymbol keeps the italic shape.

    Edit hereOpen in editor

  • Bold text inside a formula

    P ( rain ) = 0.3
    LaTeX
    P(\textbf{rain}) = 0.3
    Edit hereOpen in editor

  • Matrix equation

    A x = b
    LaTeX
    \mathbf{A}\mathbf{x} = \mathbf{b}
    Edit hereOpen in editor

  • Bold operators and numbers

    ∇ ⋅ E = ρ ε 0
    LaTeX
    \boldsymbol{\nabla} \cdot \mathbf{E} = \frac{\rho}{\varepsilon_0}
    Edit hereOpen in editor

In a LaTeX document

These commands work in the text of a .tex document (Overleaf, TeX Live, MiKTeX), not inside math. The box on the right shows what the compiled PDF looks like.

  • Bold words in a sentence

    LaTeX
    The result is \textbf{not} significant.
    Compiled result

    The result is not significant.

  • Bold and italic

    LaTeX
    \textbf{Note:} read \textbf{\textit{every}} step.
    Compiled result

    Note: read every step.

  • A whole paragraph in bold

    LaTeX
    {\bfseries This paragraph is bold from start to end.\par}

    End with \par inside the braces so the paragraph is finished while bold is still on.

    Compiled result

    This paragraph is bold from start to end.

Bold text: \textbf and \bfseries

\textbf{…} bolds the text in its argument and is the command to reach for first. \bfseries is the declaration form: it turns bold on until the end of the current group, so {\bfseries …} or an environment is the way to bold a longer passage or every cell of a table column.

The old \bf from plain TeX still works in the standard classes but is deprecated in LaTeX2e: it resets italics instead of combining with them. Use \textbf or \bfseries.

Bold math: \mathbf, \boldsymbol and \bm

\mathbf switches to an upright bold font. It works on Latin letters and digits only; Greek lowercase letters and operators stay unchanged. That makes it the usual choice for vectors and matrices in engineering notation.

\boldsymbol (amsmath) and \bm (bm package) make the symbol itself bold, keeping its italic shape, and they also work for Greek letters, ∇, ∂ and most operators. Many authors prefer \bm in documents because its spacing is more reliable.

LaTeX
\usepackage{amsmath}  % \boldsymbol
\usepackage{bm}       % \bm

$\bm{\alpha} + \mathbf{x}$

Common mistakes

  • \mathbf has no effect on Greek lowercase letters, so the α stays plain.

    Instead of
    \mathbf{\alpha}
    Write
    \boldsymbol{\alpha}

  • Markdown asterisks are printed literally in LaTeX.

    Instead of
    **important**
    Write
    \textbf{important}

  • ^ is math-only; using it in text mode stops with "Missing $ inserted".

    Instead of
    \textbf{x^2 + y^2}
    Write
    $\mathbf{x}^2 + \mathbf{y}^2$

  • The old two-letter commands reset each other, so you get italic only. The LaTeX2e commands combine.

    Instead of
    {\bf \it text}
    Write
    \textbf{\textit{text}}

In Overleaf, MathJax and Word

  • Overleaf and pdfLaTeX

    \textbf, \bfseries and \mathbf need nothing extra. \boldsymbol needs amsmath and \bm needs \usepackage{bm}. If a font has no bold version you get a "Font shape undefined" warning and a substitute.

  • MathJax and KaTeX

    MathJax supports \textbf, \mathbf, \boldsymbol and \pmb inside math, but not \bm or \bfseries. KaTeX accepts \bm as well. In Markdown, bold normal text with **…** outside the math.

  • Microsoft Word

    For text use Word's Bold button (Ctrl+B). For a formula, build it in the editor on this page and use Copy for Word; check bold symbols after pasting and apply bold in Word's equation tools if one comes through plain.

Bold in LaTeX: questions

How do I bold text in LaTeX?
Use \textbf{text}. For a longer passage, {\bfseries …} keeps bold on until the closing brace.
How do I make a bold symbol in math mode?
Use \mathbf{x} for upright bold letters and \boldsymbol{x} or \bm{x} for bold italic letters and bold Greek symbols.
Why does \mathbf not work on Greek letters?
\mathbf only switches the font for Latin letters and digits. Greek letters come from a different font, so use \boldsymbol{\alpha} or \bm{\alpha}.
What is the difference between \textbf and \bf?
\textbf is the LaTeX2e command and combines with italics. \bf is a deprecated plain-TeX switch that cancels other font changes; avoid it in new documents.
How do I make text bold and italic at the same time?
Nest the commands: \textbf{\textit{text}}, or {\bfseries\itshape text}.

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