Double prime (″) is the Unicode character at U+2033 in the General Punctuation block. Official name: DOUBLE PRIME. It is used for inches, arcseconds / seconds of time, and second-order primes in math.
Remember
Character ″
Unicode U+2033
Named entity ″
Hex entity ″
Decimal ″
CSS escape \2033
Not the same ′ · "" · "
Prefer ″ in HTML markup (capital P). You can also type ″ in UTF-8, or use numeric forms when needed.
Double prime rendered alone and in common measurement / math uses.
Example5′ 10″
Large glyph″
Compared″ ′ ‴ "
With entitiesNamed: ″ | Hex: ″ | Decimal: ″
Code
Complete HTML Example
One page that shows Double Prime with named, hex, decimal, CSS escape, and a typed character. Use View Output or open the live editor.
Named + Hex + Decimal + CSS + Typed
Five ways to produce ″, plus height and math examples.
html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Double Prime (″) in HTML</title>
<style>
#point::after {
content: "\2033";
}
</style>
</head>
<body>
<p>Double Prime using Named Entity: ″</p>
<p>Double Prime using Hex Code: ″</p>
<p>Double Prime using HTML Code: ″</p>
<p id="point">Double Prime using CSS Entity: </p>
<p>Typed directly: ″</p>
<p>Height: 5′ 10″</p>
<p>Second derivative: f″(x)</p>
</body>
</html>
Double Prime using Named Entity: ″
Double Prime using Hex Code: ″
Double Prime using HTML Code: ″
Double Prime using CSS Entity: ″
Typed directly: ″
Height: 5′ 10″
Second derivative: f″(x)
How It Works
1. Named:″ is the HTML5 name for U+2033 → ″. Best default in markup (capital P).
2. Hex:U+2033 → ″ in HTML. Same glyph as the named form.
3. Decimal: same code point as 8243 → ″. Same result as hex and named.
4. CSS: use \2033 in content (not an HTML entity). #point::after appends that ″ after the paragraph text.
5. Typed / uses: paste ″ in UTF-8, or write 5′ 10″ and f″(x) for real-world examples.
Pitfalls & Tips
Common mistakes when working with Double Prime.
Case
Capital P matters
″ is double prime (″). ′ is single prime (′). The names are case-sensitive.
""
Not two quotation marks
Typing "" or using "" is not the same as ″. Use the real double-prime character for units and math.
′
Pair with single prime
For height like 5′ 10″, use ′ for feet and ″ for inches.
CSS vs HTML
Do not mix escapes
\2033 belongs in CSS strings. ″ / ″ / ″ belong in HTML.
Fonts
Punctuation font coverage
Some fonts draw ″ almost like straight quotes. Prefer a font with clear General Punctuation primes for display.
Semicolon
End named entities
Always finish with ; — write ″, not &Prime.
Compatibility
Browser Support
Double prime (U+2033) and its entity forms (″, ″, ″, CSS \\2033) are supported in all mainstream browsers. Visible glyphs depend on punctuation font coverage.
✓ Universal support
Double Prime (″)
Encode with named, 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+2033 / entitiesFull support
Bottom line: Prefer ″ in HTML. Use ″ / ″ when numeric form is required, and \\2033 only inside CSS content.
Remember
Key Takeaways
Unicode: double prime is U+2033 (decimal 8243) — glyph ″.
HTML: prefer ″ — also ″ / ″ / type ″.
CSS: use \2033 inside content for generated text.
Meaning:″ = inches / seconds / second prime — not ′, not "".
Use ″ (named), ″ (hex), ″ (decimal), type ″ directly in UTF-8, or the CSS escape \2033 in content. Prefer ″ in normal HTML.
U+2033 (DOUBLE PRIME). Hex 2033, decimal 8243. It belongs to the General Punctuation block (U+2000–U+206F).
Yes. Use ″ (capital P). Numeric forms ″ and ″ also work. Do not use ′ — that is the single prime U+2032.
Use it for inches (e.g. 5′ 10″), arcseconds or seconds of time, and second-order primes in math (f″). Prefer ′ for feet / arcminutes / first derivatives.
HTML entities (″, ″, or ″) go in markup. The CSS escape \2033 goes in stylesheet strings (usually content on ::before/::after).
No. ″ is ″ (U+2033). ′ is ′ (U+2032). Two ASCII quotation marks "" are U+0022 twice — not a double prime.
🤔
Did you know?
Double prime is Unicode U+2033 (decimal 8243) — glyph ″ in the General Punctuation block. HTML5 names it ″ (capital P). Common uses: inches, arcseconds / seconds of time, and the second derivative in math (e.g. f″(x)). Single prime is ′ (U+2032).
