Tools/Unicode Escape

Unicode Escape Sequences Studio

Convert Unicode text to ES6 (\u{1F680}), Java/C# surrogate pairs (🚀), Python (\U0001F680), and CSS escapes, or decode back to text.

3Escape Entities Detected

2Astral Plane Glyphs (> U+FFFF)

34Total Unicode Codepoints

es6Target Syntax

Programming Language / Escape Standard:

Quick Presets:

Font Size (16px):

Plain Unicode Text (To Encode)Live Input Buffer

Unicode 16.0: Rocket 🚀 & Stars ★ 💖

Generated Escape Literals Output

Unicode 16.0: Rocket \u{1F680} & Stars \u2605 \u{1F496}

Surrogate Pair & Multi-Language Escape Anatomy

Glyph	Codepoint	ES6 JavaScript	Java / C# (Surrogates)	Python 32-bit	CSS Content
U	U+0055	\u0055	\u0055	\u0055	\000055
n	U+006E	\u006E	\u006E	\u006E	\00006E
i	U+0069	\u0069	\u0069	\u0069	\000069
c	U+0063	\u0063	\u0063	\u0063	\000063
o	U+006F	\u006F	\u006F	\u006F	\00006F
d	U+0064	\u0064	\u0064	\u0064	\000064
e	U+0065	\u0065	\u0065	\u0065	\000065
	U+0020	\u0020	\u0020	\u0020	\000020
1	U+0031	\u0031	\u0031	\u0031	\000031
6	U+0036	\u0036	\u0036	\u0036	\000036
.	U+002E	\u002E	\u002E	\u002E	\00002E
0	U+0030	\u0030	\u0030	\u0030	\000030
:	U+003A	\u003A	\u003A	\u003A	\00003A
	U+0020	\u0020	\u0020	\u0020	\000020
R	U+0052	\u0052	\u0052	\u0052	\000052
o	U+006F	\u006F	\u006F	\u006F	\00006F
c	U+0063	\u0063	\u0063	\u0063	\000063
k	U+006B	\u006B	\u006B	\u006B	\00006B
e	U+0065	\u0065	\u0065	\u0065	\000065
t	U+0074	\u0074	\u0074	\u0074	\000074
	U+0020	\u0020	\u0020	\u0020	\000020
🚀	U+1F680	\u{1F680}	0xD83D + 0xDE80	\U0001F680	\01F680
	U+0020	\u0020	\u0020	\u0020	\000020
&	U+0026	\u0026	\u0026	\u0026	\000026
	U+0020	\u0020	\u0020	\u0020	\000020

The Architecture of Unicode Escape Sequences in Compilers & Runtimes

When software compilers, source code files, and JSON payloads are transmitted across 7-bit ASCII channels, international Unicode characters can be corrupted by encoding mismatches. Unicode escape sequences allow programmers to represent any Unicode character purely with ASCII letters, digits, and backslashes:

1. Basic Multilingual Plane (BMP $\le$ U+FFFF):Represented uniformly as 4 hex digits (e.g. \u0627 for Urdu Alif).

2. Supplementary Astral Planes (> U+FFFF):Emojis and historic scripts (e.g. U+1F680) require either ES6 curly braces (\u{1F680}) or 16-bit surrogate pairs.

The Mathematics of UTF-16 Surrogate Pairs (U+D800 – U+DFFF)

In Java, C#, and ES5, characters > U+FFFF are divided into two 16-bit surrogate code units:

• High Surrogate: 0xD800 + ((U' - 0x10000) >> 10) (Range: 0xD800–0xDBFF)

• Low Surrogate: 0xDC00 + ((U' - 0x10000) & 0x3FF) (Range: 0xDC00–0xDFFF)

• Example 🚀 (U+1F680): High = 0xD83D, Low = 0xDE80 → 🚀

Frequently Asked Questions (FAQs)

Why does "🚀".length return 2 in JavaScript and Java?+

JavaScript and Java strings are internally represented in UTF-16 code units. Because the Rocket emoji (U+1F680) resides in the astral plane, it requires two 16-bit surrogate code units (🚀), causing string.length to return 2 instead of 1.

How do I use Unicode escapes in CSS pseudo-elements (::before / ::after)?+

In CSS, use a backslash followed by the hex codepoint (e.g. content: "\1F680" or content: "\2022"). Select the "CSS Content" mode to generate valid CSS escape literals.

Can this tool decode JSON payloads containing escaped strings?+

Yes! Paste your JSON escaped strings (e.g. {"msg": "\u0627\u0631\u062F\u0648"}) and select "Decode" to view the readable Unicode text.