deburr()

deburr(str): string

Removes diacritical marks and converts ligatures to basic Latin letters.

💎 Why is this a Hidden Gem?

Removes accents and expands ligatures (e.g., "æ" → "ae"), enabling ASCII-safe comparisons and search indexing.

note

Uses NFD normalization. Expands ligatures (œ→oe, ß→ss, æ→ae, Þ→Th, etc.).

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Parameters

str: string

The string to deburr.

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Returns: string

The deburred string.

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Since

2.0.0

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Performance

O(n) time where n is string length. Uses native normalize() and object lookup for ligatures.

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Also known as

deburr (Lodash, es-toolkit, Modern Dash) · ❌ (Remeda, Radashi, Ramda, Effect, Antfu)

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Example

deburr('café');      // => 'cafe'
deburr('Müller');    // => 'Muller'
deburr('Straße');    // => 'Strasse'
deburr('Œuvre');     // => 'OEuvre'
deburr('Þór');       // => 'Thor'
deburr('Łódź');      // => 'Lodz'

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How it works?

Removes diacritical marks and converts ligatures to basic Latin letters.

Process

Ligature Expansion

Input	Output
œ	oe
æ	ae
ß	ss
Þ	Th
Ø	O

Examples

Input	Output
café	cafe
Müller	Muller
Straße	Strasse
Œuvre	OEuvre
Þór	Thor
Łódź	Lodz

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Use Cases

Sanitize search queries 📌

Normalize user input for search indexing or comparison. Essential for building resilient search features that handle international characters.

#sanitize#search#queries#accents#normalize#international#i18n

const query = deburr('Crème Brûlée'); // 'Creme Brulee'

Generate URL slugs from international text

Strip diacritics before generating URL-safe slugs. Essential for multilingual apps where titles contain accented characters.

#slug#URL#international#normalize#SEO#routing#i18n#seo

const toSlug = (title: string) =>
  deburr(title).toLowerCase().replace(/[^a-z0-9]+/g, '-').replace(/(^-|-$)/g, '');

toSlug('Café résumé — été 2025');
// => 'cafe-resume-ete-2025'

Normalize strings for fuzzy search matching

Remove accents before comparing strings so users can search without typing diacritics.

#fuzzy#search#normalize#accent#insensitive#filter#i18n

const normalize = (s: string) => deburr(s).toLowerCase();

const products = ['Gruyère', 'Comté', 'Beaufort', 'Époisses'];
const query = 'comte';
const results = products.filter((p) => normalize(p).includes(normalize(query)));
// => ['Comté']

Normalize user names for avatar initials

Strip accents before extracting initials for avatar placeholders. Essential for design systems with initial-based avatar components.

#avatar#initials#normalize#display#design system#a11y

const getInitials = (name: string) =>
  deburr(name)
    .split(" ")
    .map((part) => part[0])
    .join("")
    .toUpperCase();

getInitials("Rene Descartes"); // => "RD"
getInitials("Jose Garcia");    // => "JG"

Build search index entries

Deburr product names and descriptions before indexing for search. Critical for e-commerce search engines handling multilingual catalogs.

#search#index#build#catalog#normalize#seo#performance

const buildSearchEntry = (product) => ({
  id: product.id,
  searchText: deburr(`${product.name} ${product.description} ${product.category}`).toLowerCase(),
  original: product,
});

const searchIndex = products.map(buildSearchEntry);

// Search matches "creme" even if product is "Creme"
const results = searchIndex.filter((entry) =>
  entry.searchText.includes(deburr(query).toLowerCase())
);