Unicode Escape Converter

What this Unicode escape converter does

This converter turns Unicode text into language and format-specific escape syntax, then decodes supported escape representations back to characters. It covers JavaScript \uXXXX, JavaScript \u{...}, strict JSON escapes, Python \u and \U forms, Java UTF-16 escapes, HTML numeric character references, CSS escapes and human-readable U+ notation. The page processes text locally in your browser and does not execute decoded content.

The important rule is that escape syntax belongs to a parser. A sequence valid in JavaScript may be invalid in JSON, and an HTML numeric reference is not JavaScript syntax. Use the syntax selector before decoding so malformed input is reported instead of quietly interpreted by the wrong rules.

Unicode escape formats at a glance

How \uXXXX works

The four-digit \uXXXX form stores hexadecimal digits in source text. In JavaScript, JSON and Java contexts it represents a UTF-16 code unit, not always a full Unicode scalar value. Basic Multilingual Plane characters such as é fit in one escape: \u00E9. Values above U+FFFF need a syntax that supports full code points or a valid surrogate pair.

Supplementary characters and surrogate pairs

The emoji 😀 is code point U+1F600. JSON and Java-style UTF-16 escape syntax writes it as \uD83D\uDE00: a high surrogate followed by a low surrogate. The two escapes together decode to one code point. \uD83D by itself, \uDE00 by itself, and reversed order are malformed and should be rejected.

JavaScript, JSON, Python, Java, HTML and CSS differences

Modern JavaScript accepts code-point escapes such as \u{1F600}. Strict JSON does not; JSON uses \uXXXX and surrogate pairs for supplementary characters. Python uses \uXXXX for BMP values and \UXXXXXXXX for long escapes. Java strings use UTF-16 escapes. HTML uses numeric character references such as é and é. CSS uses a backslash followed by one to six hexadecimal digits and may need a terminating space.

Auto-detect is useful for obvious markers, but it is deliberately conservative. The input \u00E9 is shared by JavaScript, JSON, Python and Java, so the converter reports it as ambiguous. By contrast, \u{1F600} is JavaScript code-point syntax, \U0001F600 is Python-style syntax, and 😀 is an HTML hexadecimal reference. When correctness matters, choose the exact input syntax instead of relying on guessing.

Unicode escapes are not UTF-8 bytes

é
Code point: U+00E9
Escape: \u00E9
UTF-8 bytes: C3 A9

Escapes are text notation. UTF-8 bytes are an encoded storage or transport representation. Do not turn the UTF-8 bytes C3 A9 into \uC3A9 or HTML references é when you mean é.

Literal vs interpreted escapes

The text \u00E9 can be an escape sequence for é, or it can be six literal characters: backslash, u, zero, zero, E, nine. The text \\u00E9 usually decodes one layer to the literal string \u00E9. This tool reports a remaining-layer notice instead of automatically decoding repeatedly.

Separators are also syntax-sensitive. Continuous source-code strings normally use no separator, while Unicode notation is often easier to read with spaces or new lines. The All representations option produces one structured row per code point so you can compare JavaScript, JSON, Python, Java, HTML, CSS, UTF-8 bytes and UTF-16 code units without mixing those formats into one ambiguous output string.

Avoid double escaping

Double escaping happens when already escaped text is escaped again, such as \u00E9 becoming \\u00E9. That may be correct when a string is nested inside another string, but it is often a pipeline bug. Decode one layer at a time and stop when the application contract says the value is ordinary text.

How to use the tool

1. Choose Encode or Decode.
2. For Encode, select the output syntax and character handling.
3. Choose hexadecimal casing and a separator only when that syntax benefits from separated values.
4. For Decode, select the input syntax or Auto-detect.
5. Use Advanced options only when normalization is intentional.
6. Review warnings, statistics and decoded output before copying, downloading or using output as the next input.

Use Escape non-ASCII characters when you want readable ASCII text with non-ASCII characters represented numerically. Use Escape all characters when every code point must be visible as notation. Preserve printable ASCII keeps ordinary ASCII letters and punctuation readable while still escaping controls and non-ASCII characters.

Privacy and processing

This tool runs in your browser. Your input is not submitted to UnicodeNow. Output is written as textarea text, not inserted as executable markup or code.

Common uses

• Preparing source-code strings.
• Debugging escaped API values.
• Converting emoji to surrogate pairs.
• Inspecting code-point notation.
• Converting HTML numeric references.
• Comparing language-specific syntax.
• Diagnosing double escaping.

Frequently asked questions