Unicode Encoder/Decoder — Free Online \\u Escape Sequence Tool
Encode text to Unicode escape sequences (\\uXXXX) and decode Unicode escapes back to readable characters — supports BMP and supplementary characters.
Frequently Asked Questions
Unicode Escape Sequences in Programming Languages
Unicode escape sequences provide a way to include any Unicode character in source code using only ASCII characters. This is valuable for including non-ASCII characters in code files that might not support UTF-8, for embedding characters that are invisible or confusable, and for creating portable string representations.
The Basic Multilingual Plane (BMP, U+0000 to U+FFFF) covers most common characters including Latin, Cyrillic, Greek, Arabic, Hebrew, Chinese, Japanese, and Korean. These use 4-digit escapes:\\u4E2D = 中 (Chinese for "middle"). Supplementary planes (emoji, historic scripts, mathematical symbols) require 8-digit escapes: \\U0001F600 = 😀.
Security note: Unicode contains visually identical characters from different scripts — a technique called a homograph attack. аpple.com vs apple.com looks identical but the first uses Cyrillic 'а' (U+0430). When security is important, normalize unicode input with NFKC normalization and restrict allowed character ranges.