Language Support

Every language is an isolated definition imported from @tanstack/highlight/languages/<name>. Aliases normalize only when their target definition is registered.

Language matrix

Language	Export	Aliases	Context-aware behavior
Apache	apache	-	Directives, tags, comments
CSS	css	-	Strings and comments protect inner syntax
Diff	diff	patch	Metadata, inserted, and deleted lines
Dockerfile	dockerfile	docker	Common directives, variables, commands
EJS	ejs	-	HTML plus optional JavaScript delegation
Env	env	dotenv	Properties, values, comments
HTML	html	htm, xml, angular-html	Optional JavaScript/TypeScript and CSS delegation
HTTP	http	-	Methods, headers, protocol, paths
JavaScript	js	javascript, mjs, cjs, js-vue	Templates, interpolation, regex literals
JSON	json	jsonc, json5	Properties, comments, strings, literals
JSX	jsx	-	JavaScript plus contextual JSX tags
Markdown	markdown	md	Optional fenced-language delegation
Mermaid	mermaid	-	Common diagram declarations and arrows
Nginx	nginx	-	Directives, variables, URLs, comments
Plaintext	plaintext	text, txt, -->	Escaping only
Python	python	py	Triple strings, prefixes, decorators, comments
Scheme	scheme	scm, racket	Comments, strings, forms, literals
Shell	shell	bash, sh, zsh, cmd, console	Heredocs, parameter expansion, comment boundaries
SQL	sql	-	Strings, comments, common SQL clauses
Svelte	svelte	-	Markup plus optional script/style and expression delegation
TOML	toml	-	Strings, comments, tables, properties
TypeScript	ts	typescript, angular-ts	JavaScript scanner plus TypeScript keywords/types
TSX	tsx	-	TypeScript, contextual JSX, generic disambiguation
Vue	vue	-	Template markup plus optional script/style delegation
YAML	yaml	yml	Comment boundaries and block scalars

Registration matters

import { createHighlighter } from '@tanstack/highlight/core'
import { html } from '@tanstack/highlight/languages/html'

const markupOnly = createHighlighter({ languages: [html] })

markupOnly highlights tags and attributes, but leaves <script> and <style> bodies uncolored. Add the delegated languages explicitly:

import { css } from '@tanstack/highlight/languages/css'
import { js } from '@tanstack/highlight/languages/js'

const withEmbeddings = createHighlighter({
  languages: [html, css, js],
})

Quality boundary

Support means useful highlighting for valid code commonly found in documentation. It does not mean compiler conformance or parity with an IDE grammar. The regression suite concentrates on contexts where simple priority regexes are predictably wrong.

Unknown or unregistered language names normalize to the configured fallback, which defaults to plaintext.

See Embedded Languages and Custom Languages for the registry model.