Left Right Double Arrow

A symbol from the Arrow Symbols collection. Click the symbol or the button below to copy.

Symbol: ⇔
Unicode: U+21D4
HTML entity: ⇔
Category: Arrow Symbols

Export

Download Left Right Double Arrow as a vector SVG or a raster PNG.

PNG size

SVG uses the system font stack — open in any vector editor and convert to outlines if needed. PNGs have a transparent background.

15 of 46 in the arrow symbols collection

About the left right double arrow symbol

Known as the Left Right Double Arrow, this character consists of a horizontal line with an arrowhead at both ends. It belongs to the Arrows block and represents a bidirectional flow or a permanent connection between two points. In formal contexts, it is most frequently read aloud as if and only if or is equivalent to, signaling that two statements are logically identical.

Usage of this symbol is centered primarily within mathematics and logic to denote material equivalence between propositions. Outside of technical proofs, it appears in chemistry to indicate a reversible reaction that occurs in both directions simultaneously. In general typography and social media, it serves as a visual shorthand for a two-way street, a trade-off, or a mutual relationship between two distinct concepts.

How to type Left Right Double Arrow

Native keyboard shortcuts for each operating system — derived from the codepoint, so the steps below are always accurate.

Windows

2 options

In Word / Outlook: type 21D4 then press Alt + X.
Anywhere: press Win + . to open the emoji & symbol picker, then search.

macOS

2 options

Enable “Unicode Hex Input” in System Settings → Keyboard, then hold Option and type 21D4.
Or: Control + Command + Space opens the Character Viewer — search by name.