The LaTeX command for downarrow (↓) is \downarrow.
\downarrowWriting a paper? The table generator and the BibTeX cleaner are one click away, no account.
Write \downarrow inside math mode, that is between $…$ for inline math or in a \[ … \] or equation block for display math. It is part of core LaTeX math, so no extra package is required.
Arrows are relations in LaTeX, so \downarrow gets the same thick spacing as an equals sign. In running text, outside math mode, the same sign is \textdownarrow. With unicode-math under XeLaTeX or LuaLaTeX, typing ↓ in a formula gives the same symbol.
$A \downarrow B$Open this example in the live preview: it renders as you type, with no compiler and no signup.
\leftrightarrow\Leftarrow\Rightarrow\Leftrightarrow\iff\implies\uparrow\updownarrow\nearrow\searrow\swarrow\nwarrow\mapsto\longmapstoArrows in LaTeX: the full table or search all 350+ LaTeX symbols.
Use \downarrow in math mode; it needs no extra package. For example, $A \downarrow B$.
None: \downarrow is built into LaTeX, so no extra package is required.