Unicode Encoder/Decoder Free Online Tool 2026

Last updated March 22, 2026

What Is Unicode Encoding?

Unicode encoding converts characters to various text representations — escape sequences, HTML entities, UTF-8 hex bytes, and percent-encoded URLs. The Unicode Encoder/Decoder handles all common formats, making it easy to prepare text for different programming environments and debug encoding issues.

Unicode Escape Sequences (JavaScript / Java)

Encode special characters as \uXXXX escape sequences:

Input text: Hello, 世界! ©

JavaScript/Java escape sequences:
Hello, \u4e16\u754c! \u00a9

Extended (ES6) for characters above U+FFFF:
Emoji 😀 → \u{1F600}
Emoji 🎉 → \u{1F389}

Java (surrogate pairs for supplementary planes):
😀 → \uD83D\uDE00
🎉 → \uD83C\uDF89

HTML Entity Encoding

Convert characters to HTML entities for safe use in HTML markup:

Input:  © 2024

Named entities:
<script>alert("XSS")</script> © 2024

Decimal numeric entities:
<script>alert("XSS")</script> © 2024

Hexadecimal numeric entities:
<script>alert("XSS")</script> © 2024

UTF-8 Hex Byte Encoding

See the raw UTF-8 bytes for any character:

Character   Code Point   UTF-8 Bytes (hex)
---------   ----------   -----------------
A           U+0041       41
é           U+00E9       C3 A9
€           U+20AC       E2 82 AC
世          U+4E16       E4 B8 96
😀          U+1F600      F0 9F 98 80

Full string: "Héllo"
UTF-8 hex:   48 C3 A9 6C 6C 6F

Percent Encoding (URL Encoding)

Encode characters for safe use in URLs:

Input: https://example.com/search?q=hello world&lang=中文

Percent-encoded:
https://example.com/search?q=hello%20world&lang=%E4%B8%AD%E6%96%87

Individual character encoding:
Space  → %20
&      → %26
=      → %3D
中     → %E4%B8%AD  (3 UTF-8 bytes)
文     → %E6%96%87  (3 UTF-8 bytes)

CSS Unicode Escapes

Use Unicode characters in CSS content properties and font icon declarations:

/* CSS unicode escape format: \XXXXXX */

/* Font Awesome icon in CSS */
.icon-home::before {
  content: "\f015";  /* home icon */
}

/* Special characters in generated content */
.quote::before {
  content: "\201C";  /* left double quotation mark " */
}

.quote::after {
  content: "\201D";  /* right double quotation mark " */
}

/* Copyright symbol */
.footer::after {
  content: "\00A9 2024";  /* © 2024 */
}

Decoding Encoded Text

Paste any encoded text and the decoder identifies the format and converts it back:

Input (HTML entities):
<h1>Café</h1>

Decoded:
<h1>Café</h1>

---

Input (Unicode escapes):
\u0048\u0065\u006C\u006C\u006F

Decoded:
Hello

---

Input (percent-encoded):
%48%65%6C%6C%6F%20%57%6F%72%6C%64

Decoded:
Hello World

Unicode Normalization Forms

The same character can be encoded in multiple ways. The encoder shows normalization form differences:

Character: é (e with acute accent)

NFC (precomposed):
  Single code point: U+00E9
  UTF-8: C3 A9

NFD (decomposed):
  Two code points: U+0065 U+0301
  UTF-8: 65 CC 81
  (base 'e' + combining acute accent)

Both look identical when rendered but are different byte sequences.
Use NFC for storage and exchange (most common on the web).

Bidirectional Text Control Characters

The encoder reveals invisible Unicode control characters in bidirectional text:

Input: "Hello مرحبا World"

Visible control characters:
U+200F  RIGHT-TO-LEFT MARK (invisible)
U+200E  LEFT-TO-RIGHT MARK (invisible)
U+202A  LEFT-TO-RIGHT EMBEDDING
U+202B  RIGHT-TO-LEFT EMBEDDING
U+202C  POP DIRECTIONAL FORMATTING

Encoded to show hidden characters:
Hello \u200Fمرحبا\u200E World

Practical Use Cases

• Preparing special characters for HTML templates without breaking markup
• Debugging encoding issues in API responses or log files
• Converting internationalized text for JavaScript string literals
• Encoding non-ASCII characters in URL query parameters
• Inserting Unicode symbols in CSS-generated content
• Understanding how emoji are stored in UTF-8 databases
• Detecting hidden bidirectional control characters in text

Quick Reference: Common Encodings

Character  HTML Named   HTML Decimal  JS Escape   URL Encode
---------  ----------   ------------  ---------   ----------
&          &        &        \u0026      %26
<          <         <        \u003C      %3C
>          >         >        \u003E      %3E
"          "       "        \u0022      %22
©          ©       ©       \u00A9      %C2%A9
€          €       €      \u20AC      %E2%82%AC