The Arrows block runs from U+2190 through U+21FF and assembles the most-used arrow forms into a single 112-codepoint window. The four cardinal arrows occupy the first four codepoints — ← U+2190, ↑ U+2191, → U+2192, ↓ U+2193 — and serve as the canonical reference for almost every other arrow in the standard. Beyond them come bidirectional arrows, diagonal arrows, double-line arrows, arrows with strokes, arrows with hooks, arrows with tails, and a handful of decorative variants.
About this block
Arrows entered Unicode in version 1.0 (1991), and the block has been expanded gradually as scientific publishing demanded more variants. The mathematical use cases drove most of the additions: the double-arrow row at U+21D0–U+21D5 (⇐ ⇑ ⇒ ⇓ ⇔ ⇕) is reserved for logical implication and bi-implication, while the long arrows in the Supplemental Arrows blocks were added in Unicode 3.2 (2002) at the request of mathematicians who needed proper "—→" forms for category-theory diagrams. The standard also distinguishes hooked arrows (↪ ↩) used for injections, arrows with tails (↣) used for surjections, and bi-directional arrows (↔) used for bijections in set theory.
Stroked arrows — ↚ U+219A, ↛ U+219B, ⇍ U+21CD, ⇏ U+21CF, ⇎ U+21CE — denote negation: "does not imply", "is not mapped to". These are crucial in formal logic, where ⇏ means strict non-implication. Diagonal arrows at U+2196–U+2199 (↖ ↗ ↘ ↙) and their double-line versions are widely used in diagrams and user interfaces. Curved-tail arrows (↰ ↱ ↲ ↳) appear in flowcharts and in word-processor "return" indicators.
This is not the only place arrows live. Once the original block filled up, additional arrows were placed in three supplementary blocks: Supplemental Arrows-A at U+27F0–U+27FF, Supplemental Arrows-B at U+2900–U+297F, and Supplemental Arrows-C at U+1F800–U+1F8FF on Plane 1. The Miscellaneous Symbols and Arrows block at U+2B00–U+2BFF holds the heavy, dingbat-style arrows used in modern UI fonts. Together these blocks contain over 600 arrow characters — vastly more than any single typeface actually implements.
For most everyday uses, the original Arrows block is enough. Designers building interfaces should know that → U+2192 (RIGHTWARDS ARROW) and ➜ U+279C (HEAVY ROUND-TIPPED RIGHTWARDS ARROW) render very differently in most fonts; the bolder dingbat forms in U+2794–U+27BE are usually a better choice for buttons and calls to action, since the lightweight glyph in U+2192 is meant to read as inline text.