unicodefyi

Pure TypeScript Unicode toolkit -- character info, name search, and 17 encoding formats.

Look up any Unicode character's name, category, and block. Encode into 17 formats: UTF-8, UTF-16, UTF-32, HTML (decimal, hex, named entity), CSS, URL encoding, and language-specific escapes for JavaScript, Python, Java, Go, Ruby, Rust, and C/C++. Search ~2,950 characters by name. Includes 90 HTML named entity mappings.

Zero dependencies. Works in Node.js, Deno, Bun, and all modern browsers.

Table of Contents

• Install
• Quick Start
• What You Can Do
  • Character Lookup
  • Character Search
  • 17 Encoding Formats
  • Supplementary Plane Characters (Emoji)
  • HTML Entity Lookup
• Raw Data Access
• API Reference
• Learn More About Unicode
• Also Available
• FYIPedia Developer Tools
• License

Install

npm install unicodefyi

Quick Start

import { getEncodings, charInfo, searchCharacters, lookupHtmlEntity } from "unicodefyi";

// Encode any character into 17 formats
const enc = getEncodings("\u2713"); // CHECK MARK
console.log(enc.unicode);     // "U+2713"
console.log(enc.htmlEntity);  // "✓"
console.log(enc.css);         // "\2713"
console.log(enc.javascript);  // "\u{2713}"
console.log(enc.python);      // "\u2713"
console.log(enc.java);        // "\u2713"
console.log(enc.go);          // "\u2713"
console.log(enc.ruby);        // "\u{2713}"
console.log(enc.rust);        // "\u{2713}"
console.log(enc.cCpp);        // "\u2713"
console.log(enc.urlEncoded);  // "%E2%9C%93"
console.log(enc.utf8Bytes);   // "e2 9c 93"
console.log(enc.utf16beBytes);// "27 13"
console.log(enc.utf32beBytes);// "00 00 27 13"

// Character info -- name, category, block
const info = charInfo("\u2713");
console.log(info?.name);         // "CHECK MARK"
console.log(info?.category);     // "So"
console.log(info?.categoryName); // "Other Symbol"
console.log(info?.block);        // "Dingbats"

// Search characters by name
const arrows = searchCharacters("arrow", 5);
console.log(arrows[0].name);      // "LEFTWARDS ARROW"
console.log(arrows[0].character);  // "\u2190"

// HTML entity reverse lookup
lookupHtmlEntity("♥"); // "\u2665"

What You Can Do

Character Lookup

Get the Unicode name, general category, and block for any character in the bundled dataset (~2,950 common BMP characters covering Latin, Greek, Cyrillic, symbols, arrows, math operators, dingbats, and more). The Unicode Standard assigns every character a unique name, a two-letter general category code, and a block designation indicating which range of the codespace it belongs to.

import { charInfo } from "unicodefyi";

const info = charInfo("A");
info?.name         // "LATIN CAPITAL LETTER A"
info?.category     // "Lu"
info?.categoryName // "Uppercase Letter"
info?.block        // "Basic Latin"
info?.blockSlug    // "basic-latin"
info?.codepoint    // 65
info?.encodings    // all 17 encoding formats

Learn more: Unicode Character Search · Unicode Blocks · Scripts

Character Search

Search the bundled character name dataset by substring:

import { searchCharacters } from "unicodefyi";

const results = searchCharacters("ARROW");
// Returns CharInfo[] with name, category, block, encodings
// e.g. LEFTWARDS ARROW, UPWARDS ARROW, RIGHTWARDS ARROW, ...

const limited = searchCharacters("LETTER", 10);
// Limit results (default: 50)

Learn more: Unicode Block Browser · REST API Docs

17 Encoding Formats

Encode any Unicode character into 17 different representations covering web standards, programming languages, and binary formats. This is the most comprehensive encoding toolkit available -- covering 6 more formats than symbolfyi's 11, adding Go, Ruby, Rust, C/C++, UTF-32, and decimal output.

| Format | Field | Example (U+2713) | Description | |--------|-------|---------------------|-------------| | Unicode | unicode | U+2713 | Standard Unicode notation | | Decimal | decimal | 10003 | Decimal codepoint value | | HTML Decimal | htmlDecimal | ✓ | HTML numeric character reference | | HTML Hex | htmlHex | ✓ | HTML hex character reference | | HTML Entity | htmlEntity | ✓ | Named entity (90 supported) | | CSS | css | \2713 | CSS escape sequence | | JavaScript | javascript | \u{2713} | ES6 Unicode escape | | Python | python | \u2713 | Python string escape | | Java | java | \u2713 | Java Unicode escape | | Go | go | \u2713 | Go Unicode escape | | Ruby | ruby | \u{2713} | Ruby Unicode escape | | Rust | rust | \u{2713} | Rust Unicode escape | | C/C++ | cCpp | \u2713 | C/C++ universal character name | | URL Encoded | urlEncoded | %E2%9C%93 | Percent-encoded UTF-8 | | UTF-8 Bytes | utf8Bytes | e2 9c 93 | Raw UTF-8 byte values | | UTF-16 BE | utf16beBytes | 27 13 | Big-endian UTF-16 bytes | | UTF-32 BE | utf32beBytes | 00 00 27 13 | Big-endian UTF-32 bytes |

Learn more: Character Lookup Tool · REST API Docs · OpenAPI Spec

Supplementary Plane Characters (Emoji)

Characters above U+FFFF (including emoji) are fully supported. Language-specific escapes automatically use the correct format:

const enc = getEncodings("\uD83D\uDE00"); // GRINNING FACE U+1F600

enc.unicode;       // "U+1F600"
enc.python;        // "\U0001f600"        (8-digit)
enc.java;          // "\uD83D\uDE00"      (surrogate pair)
enc.go;            // "\U0001F600"         (8-digit uppercase)
enc.rust;          // "\u{1F600}"          (braces)
enc.cCpp;          // "\U0001f600"         (8-digit)
enc.utf8Bytes;     // "f0 9f 98 80"
enc.utf16beBytes;  // "d8 3d de 00"        (surrogate pair bytes)
enc.utf32beBytes;  // "00 01 f6 00"

HTML Entity Lookup

Resolve 90 named HTML entities back to their characters. The HTML specification defines named entities as shortcuts for commonly used characters -- & for ampersand, ♥ for the heart suit, € for the euro sign, and more.

import { lookupHtmlEntity } from "unicodefyi";

lookupHtmlEntity("&");    // "&"
lookupHtmlEntity("♥"); // "\u2665" (BLACK HEART SUIT)
lookupHtmlEntity("✓");  // "\u2713" (CHECK MARK)
lookupHtmlEntity("€");   // "\u20AC" (EURO SIGN)
lookupHtmlEntity("&fake;");   // null

Learn more: HTML Entity Reference · Unicode Character Search

Raw Data Access

Access the bundled data maps directly:

import { HTML_ENTITIES, HTML_ENTITY_TO_CHAR, GENERAL_CATEGORY_NAMES, CHAR_NAMES } from "unicodefyi";

// 90 HTML entity mappings
HTML_ENTITIES.get(0x2713);          // "✓"
HTML_ENTITY_TO_CHAR.get("✓"); // "\u2713"

// 30 Unicode general category names
GENERAL_CATEGORY_NAMES.get("Sm");   // "Math Symbol"

// ~2,950 character names
CHAR_NAMES.get(0x2713);             // "CHECK MARK"

API Reference

getEncodings(char: string): EncodingInfo

Compute 17 encoding representations for a single Unicode character. Accepts BMP characters and supplementary plane characters (emoji, etc.). Throws if the input is not exactly one codepoint.

charInfo(char: string): CharInfo | null

Get full Unicode character info (name, category, block) plus all 17 encodings. Returns null if the character is not in the bundled ~2,950 character dataset. Throws if input is not exactly one codepoint.

searchCharacters(query: string, limit?: number): CharInfo[]

Search characters by name substring (case-insensitive). Returns up to limit results (default: 50). Each result includes name, category, block, and all encodings.

getCategoryName(code: string): string

Get the human-readable name for a Unicode general category code (e.g., "Sm" returns "Math Symbol").

lookupHtmlEntity(entity: string): string | null

Look up the character for a named HTML entity string (e.g., "&"). Returns null if not found.

HTML_ENTITIES: ReadonlyMap<number, string>

Map of codepoint numbers to HTML entity strings (90 entries).

HTML_ENTITY_TO_CHAR: ReadonlyMap<string, string>

Reverse map of HTML entity strings to characters.

GENERAL_CATEGORY_NAMES: ReadonlyMap<string, string>

Map of 2-letter category codes to human-readable names (30 entries).

CHAR_NAMES: ReadonlyMap<number, string>

Map of codepoints to official Unicode character names (~2,950 entries).

Learn More About Unicode

• Browse: Unicode Search · Unicode Blocks · Scripts
• Tools: Character Lookup
• API: REST API Docs · OpenAPI Spec
• Python: PyPI Package

Also Available

• Python: unicodefyi on PyPI -- same 17 encodings + Unicode properties + character search
• Web: unicodefyi.com -- interactive Unicode character explorer

FYIPedia Developer Tools

Part of the FYIPedia open-source developer tools ecosystem.

| Package | PyPI | npm | Description | |---------|------|-----|-------------| | colorfyi | PyPI | npm | Color conversion, WCAG contrast, harmonies -- colorfyi.com | | emojifyi | PyPI | npm | Emoji encoding & metadata for 3,953 emojis -- emojifyi.com | | symbolfyi | PyPI | npm | Symbol encoding in 11 formats -- symbolfyi.com | | unicodefyi | PyPI | npm | Unicode lookup with 17 encodings -- unicodefyi.com | | fontfyi | PyPI | npm | Google Fonts metadata & CSS -- fontfyi.com | | distancefyi | PyPI | npm | Haversine distance & travel times -- distancefyi.com | | timefyi | PyPI | npm | Timezone ops & business hours -- timefyi.com | | namefyi | PyPI | npm | Korean romanization & Five Elements -- namefyi.com | | unitfyi | PyPI | npm | Unit conversion, 220 units -- unitfyi.com | | holidayfyi | PyPI | npm | Holiday dates & Easter calculation -- holidayfyi.com | | cocktailfyi | PyPI | -- | Cocktail ABV, calories, flavor -- cocktailfyi.com | | fyipedia | PyPI | -- | Unified CLI: fyi color info FF6B35 -- fyipedia.com | | fyipedia-mcp | PyPI | -- | Unified MCP hub for AI assistants -- fyipedia.com |

License

MIT