\phantom - LaTeX spacing command

\phantom{x}

Renderer support

Package	MathJax	KaTeX	XeTeX
`base`	MathJax: Full	KaTeX: Full	XeTeX: Full
`textmacros`	MathJax: Full	KaTeX: Full	XeTeX: Full

Syntax#

\phantomm{a}math content

Argspec m — one mandatory argument. In base. Reading argspecs

\phantomm:T{a}text content

Argspec m:T — one mandatory argument. In textmacros. Reading argspecs

textmacros

\text{\phantom{abc}}

Package	Signature	Allowed mode	Notes
`base`	`m`	math	Used to reserve space in mathematical formulas equal to the size of the argument without printing it.
`textmacros`	`m:T`	text	Used for manual alignment and spacing tweaks in equations.

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

`base`
Input	Case	MathJax	KaTeX	XeTeX
`\phantom{a}`	Positive · baseline	Pass	Pass	Pass
`\phantom a`	Positive · bare[0]	Pass	Pass	Pass

`textmacros`
Input	Case	MathJax	KaTeX	XeTeX
`\phantom{a}`	Positive · baseline	Pass	Pass	Pass
`\phantom a`	Positive · bare[0]	Pass	Pass	Pass
`\phantom{a^2}`	Negative · neg:T[0]	Fail	Fail	Fail