Fast and accurate string escape/unescape utility. Convert special characters into backslash-escaped sequences (\\n, \\t, \\uXXXX) and restore them.
Escaping is the process of converting special characters into a format that can be safely embedded in contexts like source code, JSON, XML, or SQL. The escape encoder/decoder uses backslash-based escapes (\\n, \\t, \\uXXXX) — the standard defined by JavaScript, JSON, Python, and many other languages. Correct escaping prevents syntax errors, injection attacks, and data corruption. As OWASP emphasizes, proper output encoding is a cornerstone of web security.
⚡ Common Escape Sequences
| Sequence | Meaning | Unicode / ASCII |
|---|---|---|
| \\n | Newline (line feed) | U+000A |
| \\r | Carriage Return | U+000D |
| \\t | Horizontal Tab | U+0009 |
| \\b | Backspace | U+0008 |
| \\f | Form Feed | U+000C |
| \\' | Single quote | U+0027 |
| \\" | Double quote | U+0022 |
| \\\\ | Backslash | U+005C |
| \\uXXXX | Unicode character (hex) | Any BMP character |
Encode (Escape): Converts raw characters like newline, tab, double-quote, backslash into their respective escape sequences. If "Encode non-ASCII as \uXXXX" is selected, any character outside ASCII range (code point > 127) is transformed into a \\uXXXX format. This creates a pure ASCII representation — ideal for JSON without UTF-8 constraints or legacy systems.
Decode (Unescape): Reverses the process: sequences like \\n, \\t, \\u00E9 become actual characters. The parser strictly follows JavaScript/JSON escape syntax, ignoring invalid or incomplete sequences gracefully with warning messages.
Our implementation uses modern ES2021 features and handles edge cases such as escaped backslashes and high Unicode codepoints up to \\uFFFF. For surrogate pairs (emojis), the tool preserves them when unescape option is active.
Standards conformance: This tool strictly implements the escape semantics defined in ECMA-262 (13th edition) for JavaScript strings and RFC 8259 for JSON text serialization. All escape sequences are fully compliant with these specifications.
A backend developer receives user-generated comments that contain line breaks, quotes, and emojis. Before inserting into JSON response, the team escapes the text using \\n, \\" sequences to avoid breaking the JSON structure. Using this Escape Encoder, they generate safe strings that parse correctly on any JSON parser. The optional Unicode escape mode ensures ASCII-only transport across legacy protocols.
The OWASP XSS (Cross Site Scripting) Prevention Cheat Sheet mandates context‑sensitive escaping. For JavaScript/HTML contexts, backslash escaping prevents injection of malicious code. Additionally, this tool helps developers understand the difference between JavaScript encoding and HTML entity encoding. Always apply the right escape strategy based on the output context. Our encoder is safe by design — it never introduces unsafe eval or dynamic code execution.
? JavaScript Escape vs. HTML Entity Encoding – Key Differences
| Context | Encoding Method | Example | When to Use |
|---|---|---|---|
| JavaScript string / JSON | Backslash escaping (\\n, \\", \\uXXXX) |
"Hello \\"world\\""
|
Inside <script> blocks, JSON payloads, event handlers.
|
| HTML document body | HTML entities (<, >, ') |
<div>5 < 10</div>
|
Prevent XSS when inserting user data into HTML markup. |
| HTML attribute values | Quoting + entity encoding (or backslash if JS) |
data-msg=""safe""
|
Attribute injection prevention. |
Using the wrong encoder (e.g., HTML entity inside a JavaScript string) will break functionality or introduce vulnerabilities. This tool focuses on the JavaScript/JSON escape layer.
\\uXXXX is a JavaScript/JSON escape sequence (e.g., \\u00E9 = "é") and is evaluated at runtime. &#xXXXX; is an HTML/XML character reference (e.g., é = "é") that the browser parses as markup. Confusing them leads to XSS or broken strings. This tool handles \\uXXXX only.