HTML Symbol Entities
Symbols or letters that are not on your keyboard can be added to HTML using entities. Use the entity name, or the entity number as a decimal or hexadecimal reference. For example, the euro sign can be written as €, €, or €, and all three display as €.
Example
The euro sign shown three different ways.
Output: complete HTML page
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Euro Symbol</title>
</head>
<body>
<p>I will display €</p>
<p>I will display €</p>
<p>I will display €</p>
</body>
</html>
Some HTML Symbol Entities
Some common symbols (character, name, number): copyright © (©, ©), registered trademark ® (®, ®), euro € (€, €), trademark ™ (™, ™), left arrow ← (←, ←), up arrow ↑ (↑, ↑), right arrow → (→, →), down arrow ↓ (↓, ↓), and the card suits spade ♠, club ♣, heart ♥, and diamond ♦.
Some HTML Mathematical Entities
Some math symbols (character, name, number): for all ∀ (∀, ∀), partial differential ∂ (∂, ∂), there exists ∃ (∃, ∃), empty set ∅ (∅, ∅), nabla ∇ (∇, ∇), element of ∈ (∈, ∈), not an element of ∉ (∉, ∉), n-ary product ∏ (∏, ∏), and n-ary summation ∑ (∑, ∑).
Some HTML Greek Letters Entities
Some Greek letters (character, name, number): Alpha Α (Α, Α), Beta Β (Β, Β), Gamma Γ (Γ, Γ), Delta Δ (Δ, Δ), Epsilon Ε (Ε, Ε), and Zeta Ζ (Ζ, Ζ).
More Symbols
HTML supports many more symbol groups, including currency symbols, letter-like symbols, number forms, enclosed alphanumerics, box drawings, block elements, geometric shapes, miscellaneous symbols, dingbats, astrological symbols, math operators and symbols, arrows, weather symbols, musical symbols, dominoes and dice, mahjong tiles, card symbols, chess symbols, yin-yang symbols, recycling symbols, and more. Each can be added with its entity name or number.