# \textbf

Bold text labels or emphasis inside math expressions.

https://texform.dev/latex/commands/textbf

## Metadata

| Field | Value |
| --- | --- |
| Topic | [Boxes and text](https://texform.dev/latex/topics/boxes-text) |
| Packages | base, textmacros |
| Allowed mode | math, text |
| Tags | presentation |
| Commonality | high |
| Kind | prefix |

## Syntax

### base

Argument specification: `m:T`

Bold text labels or emphasis inside math expressions.

### textmacros

Argument specification: `m:T`

Used to make a short span of text bold inside MathJax text mode.

## Common tasks

### How to write bold text inside math

```latex
\textbf{Warning: } x>0
```

[Open in Playground](https://play.texform.dev/?input=%5Ctextbf%7BWarning%3A+%7D+x%3E0)

### How to bold a short label in a subscript

```latex
E_{\textbf{tot}}
```

[Open in Playground](https://play.texform.dev/?input=E_%7B%5Ctextbf%7Btot%7D%7D)

## Examples

```latex
\textbf{a}
```

[Open in Playground](https://play.texform.dev/?input=%5Ctextbf%7Ba%7D)

```latex
\textbf b
```

[Open in Playground](https://play.texform.dev/?input=%5Ctextbf+b)

```latex
\text{\textbf{a}}
```

[Open in Playground](https://play.texform.dev/?input=%5Ctext%7B%5Ctextbf%7Ba%7D%7D)

## Package variants

| Package | Argument specification | Allowed mode | Description |
| --- | --- | --- | --- |
| base | m:T | math | Bold text labels or emphasis inside math expressions. |
| textmacros | m:T | text | Used to make a short span of text bold inside MathJax text mode. |

## Renderer support

| Package | MathJax | KaTeX | XeTeX |
| --- | --- | --- | --- |
| base | full | full | full |
| textmacros | full | full | full |

## Usage frequency

0.70% of formulas in the measured corpus contain this entry, rank 54 of 263 entries with frequency data.

## In TeXForm

TeXForm parses this entry as prefix syntax; the package determines its argument specification.

### Expands to (textmacros)

```latex
\textbf{#1}
```

→

```latex
{\bf #1}
```

## See also

- [\\bmod](https://texform.dev/latex/commands/bmod)
- [\\bmqty](https://texform.dev/latex/commands/bmqty)
- [\\boxed](https://texform.dev/latex/commands/boxed)
- [\\bra](https://texform.dev/latex/commands/bra)
- [\\Bra](https://texform.dev/latex/commands/Bra)
- [\\flatfrac](https://texform.dev/latex/commands/flatfrac)
- [\\hbox](https://texform.dev/latex/commands/hbox)
- [\\iff](https://texform.dev/latex/commands/iff)
- [\\imathbb](https://texform.dev/latex/commands/imathbb)
- [\\imathbfbb](https://texform.dev/latex/commands/imathbfbb)
- [\\impliedby](https://texform.dev/latex/commands/impliedby)
- [\\implies](https://texform.dev/latex/commands/implies)
- [\\itextbb](https://texform.dev/latex/commands/itextbb)
- [\\itextbfbb](https://texform.dev/latex/commands/itextbfbb)
- [\\jmathbb](https://texform.dev/latex/commands/jmathbb)
- [\\jmathbfbb](https://texform.dev/latex/commands/jmathbfbb)
- [\\jtextbb](https://texform.dev/latex/commands/jtextbb)
- [\\jtextbfbb](https://texform.dev/latex/commands/jtextbfbb)
- [\\ket](https://texform.dev/latex/commands/ket)
- [\\Ket](https://texform.dev/latex/commands/Ket)
- [\\ketbra](https://texform.dev/latex/commands/ketbra)
- [\\Ketbra](https://texform.dev/latex/commands/Ketbra)
- [\\LaTeX](https://texform.dev/latex/commands/LaTeX)
- [\\mathstrut](https://texform.dev/latex/commands/mathstrut)
- [\\matrixdeterminant](https://texform.dev/latex/commands/matrixdeterminant)
- [\\mbox](https://texform.dev/latex/commands/mbox)
- [\\mdet](https://texform.dev/latex/commands/mdet)
- [\\mod](https://texform.dev/latex/commands/mod)
- [\\pmb](https://texform.dev/latex/commands/pmb)
- [\\pmod](https://texform.dev/latex/commands/pmod)
- [\\pmqty](https://texform.dev/latex/commands/pmqty)
- [\\Pmqty](https://texform.dev/latex/commands/Pmqty)
- [\\pod](https://texform.dev/latex/commands/pod)
- [\\qc](https://texform.dev/latex/commands/qc)
- [\\qcomma](https://texform.dev/latex/commands/qcomma)
- [\\Residue](https://texform.dev/latex/commands/Residue)
- [\\sbmqty](https://texform.dev/latex/commands/sbmqty)
- [\\skew](https://texform.dev/latex/commands/skew)
- [\\smdet](https://texform.dev/latex/commands/smdet)
- [\\spmqty](https://texform.dev/latex/commands/spmqty)
- [\\sPmqty](https://texform.dev/latex/commands/sPmqty)
- [\\stackbin](https://texform.dev/latex/commands/stackbin)
- [\\stackrel](https://texform.dev/latex/commands/stackrel)
- [\\substack](https://texform.dev/latex/commands/substack)
- [\\svmqty](https://texform.dev/latex/commands/svmqty)
- [\\TeX](https://texform.dev/latex/commands/TeX)
- [\\text](https://texform.dev/latex/commands/text)
- [\\textit](https://texform.dev/latex/commands/textit)
- [\\textnormal](https://texform.dev/latex/commands/textnormal)
- [\\textrm](https://texform.dev/latex/commands/textrm)
- [\\textsf](https://texform.dev/latex/commands/textsf)
- [\\texttt](https://texform.dev/latex/commands/texttt)
- [\\textup](https://texform.dev/latex/commands/textup)
- [\\varinjlim](https://texform.dev/latex/commands/varinjlim)
- [\\varliminf](https://texform.dev/latex/commands/varliminf)
- [\\varlimsup](https://texform.dev/latex/commands/varlimsup)
- [\\varprojlim](https://texform.dev/latex/commands/varprojlim)
- [\\vmqty](https://texform.dev/latex/commands/vmqty)
- [\\zeromatrix](https://texform.dev/latex/commands/zeromatrix)
- [\\zmat](https://texform.dev/latex/commands/zmat)

## Test cases

### base

| Input | Case | MathJax | KaTeX | XeTeX |
| --- | --- | --- | --- | --- |
| \textbf{a} | Positive: baseline | Pass | Pass | Pass |
| \textbf a | Positive: bare[0] | Pass | Pass | Pass |
| \textbf{a^2} | Negative: neg:T[0] | Pass | Fail | Fail |

### textmacros

| Input | Case | MathJax | KaTeX | XeTeX |
| --- | --- | --- | --- | --- |
| \textbf{a} | Positive: baseline | Pass | Pass | Pass |
| \textbf a | Positive: bare[0] | Pass | Pass | Pass |
| \textbf{a^2} | Negative: neg:T[0] | Fail | Fail | Fail |