Equal to by definition (≝) is the Unicode character at U+225D in Mathematical Operators. Official name: EQUAL TO BY DEFINITION. It marks a definitional equality — read “is defined as,” as in f(x) ≝ x².
Remember
Character ≝
Unicode U+225D
Hex entity ≝
Decimal ≝
CSS escape \225D
Named entity (none)
Not the same = · ≜ (triangleq) · ≡ (equiv)
Prefer ≝ or ≝ in HTML (no named form). You can also type ≝ in a UTF-8 document.
Built with Hex: ≝
Built with Decimal: ≝
Built with CSS: ≝
Typed: ≝
Definition: f(x) ≝ x²
How It Works
1. Hex:≝ inserts code point U+225D → ≝.
2. Decimal: same code point as 8797 → ≝. Same visual as hex.
3. CSS: use \225D in content (not an HTML entity). #point::after appends ≝.
4. Typed: paste ≝ in a UTF-8 document, or write a definition like f(x) ≝ x².
Pitfalls & Tips
Common mistakes when working with Equal To By Definition.
Name
No named entity
There is no HTML5 named entity for U+225D. Use ≝ or ≝.
=
Not ordinary equals
U+003D (=) is ordinary equality. Prefer ≝ when you mean “defined as.”
≜
Not triangleq
U+225C (≜, ≜) is a related “defined as” mark with a triangle — not the same glyph as ≝.
CSS vs HTML
Do not mix escapes
\225D belongs in CSS strings. ≝ / ≝ belong in HTML.
Fonts
Math font coverage
Some fonts omit Mathematical Operators. Prefer a font with solid math coverage for definition notation.
a11y
Add accessible text
Screen readers may not expand ≝ clearly. Prefer a phrase nearby such as “is defined as” when the meaning matters.
Semicolon
End references
Always finish entities with ; — write ≝, not ≝.
Compatibility
Browser Support
Equal to by definition (U+225D) and its entity forms (≝, ≝, CSS \\225D) are supported in all mainstream browsers. Visible glyphs depend on Mathematical Operators font coverage.
✓ Universal support
Equal To By Definition (≝)
Encode with hex, decimal, CSS escape, or type the character — same code point everywhere encoding is supported.
100%Browser coverage
Google ChromeSupported
Yes
Microsoft EdgeSupported
Yes
Mozilla FirefoxSupported
Yes
Apple SafariSupported
Yes
OperaSupported
Yes
Internet ExplorerAll versions
Yes
U+225DFull support
Bottom line: Prefer ≝ in HTML (no named form). Use ≝ when decimal form is required, and \\225D only inside CSS content.
Remember
Key Takeaways
Unicode: equal to by definition is U+225D (decimal 8797) — glyph ≝.
HTML: no named entity — use ≝ / ≝ / type ≝.
CSS: use \225D inside content for generated text.
Meaning: ≝ ≠ = ≠ triangleq ≜ ≠ equiv ≡.
One line:U+225D → ≝ / ≝ / CSS \225D (no named form).
Frequently Asked Questions
Use ≝ (hex), ≝ (decimal), type ≝ directly in UTF-8, or the CSS escape \225D in content. There is no named HTML entity for U+225D.
U+225D (EQUAL TO BY DEFINITION). Hex 225D, decimal 8797. It belongs to the Mathematical Operators block (U+2200–U+22FF).
No. HTML5 does not define a named entity for U+225D. Prefer ≝ or ≝.
Use it when introducing a definition (for example f(x) ≝ x²). Prefer ordinary = for computed or proven equality, and ≜ (U+225C) when you specifically want the triangle-equals “defined as” form.
HTML numeric entities (≝ or ≝) go in markup. The CSS escape \225D goes in stylesheet strings (usually content on ::before/::after).
No. U+225D is ≝ (equal to by definition). U+003D is = (ordinary equals). U+225C is ≜ (delta equal to / triangleq), a related but different definition mark.
🤔
Did you know?
Equal to by definition is Unicode U+225D (decimal 8797) — glyph ≝ (EQUAL TO BY DEFINITION) in Mathematical Operators. There is no HTML5 named entity; use ≝ or ≝. It marks a definitional equality (read “is defined as”). Nearby related marks include ≜ (≜, U+225C) and ordinary = (U+003D).
