ARIA Attribute Validator - Online Check HTML Accessibility
Paste an HTML snippet and check for common ARIA mistakes: missing labels, invalid roles, and aria‑hidden misuse. Educate your team.
UD5 Toolkit
Validate & parse BCP 47 language tags for your HTML lang attribute
| Tag | Language | Region |
|---|---|---|
en | English | - |
en-US | English | United States |
en-GB | English | United Kingdom |
zh-CN | Chinese | China |
zh-TW | Chinese | Taiwan |
zh-Hans | Chinese (Simplified) | - |
zh-Hant | Chinese (Traditional) | - |
fr-FR | French | France |
de-DE | German | Germany |
ja-JP | Japanese | Japan |
ko-KR | Korean | South Korea |
es-ES | Spanish | Spain |
es-MX | Spanish | Mexico |
pt-BR | Portuguese | Brazil |
pt-PT | Portuguese | Portugal |
it-IT | Italian | Italy |
ru-RU | Russian | Russia |
ar-SA | Arabic | Saudi Arabia |
hi-IN | Hindi | India |
nl-NL | Dutch | Netherlands |
sv-SE | Swedish | Sweden |
pl-PL | Polish | Poland |
tr-TR | Turkish | Turkey |
vi-VN | Vietnamese | Vietnam |
th-TH | Thai | Thailand |
id-ID | Indonesian | Indonesia |
ms-MY | Malay | Malaysia |
Click any tag to validate it instantly
lang attribute specifies the primary language of a webpage or a specific element. It helps search engines understand content language, improves accessibility for screen readers, and ensures proper text rendering. Using a valid BCP 47 language tag like en-US helps browsers apply correct hyphenation, font selection, and spelling dictionaries.
en, zh), optionally followed by a script subtag (4 letters, e.g., Hant), a region subtag (2 letters or 3 digits, e.g., US), and variant subtags. Examples: en-US, zh-Hant-CN.
lang attribute as a signal to determine the language of your content. Proper language tagging helps with geo-targeting, improves search result accuracy for multilingual queries, and can enhance your site's visibility in language-specific search results. It also supports proper hreflang implementation for multilingual websites.
lang attribute declares the language of the current page's content. The hreflang attribute (used in <link> tags or sitemaps) tells search engines about alternate language versions of a page. While both use BCP 47 tags, lang is for the current document, and hreflang points to other language versions. For example: <html lang="en-US"> vs <link rel="alternate" hreflang="es-MX" href="...">.
en-US (English - US), en-GB (English - UK), zh-CN (Chinese - China), fr-FR (French - France), de-DE (German - Germany), ja-JP (Japanese), es-ES (Spanish - Spain), pt-BR (Portuguese - Brazil), ar-SA (Arabic), and ru-RU (Russian). You can find a comprehensive list in the reference table on this page.
-) as separators, not underscores. For instance, en_US is invalid; the correct form is en-US. Using underscores is a common mistake inherited from programming language locale conventions (like en_US in Python or C). Always use hyphens for HTML lang attributes.
lang attribute on the <html> element for the primary language. For mixed-language content, add lang attributes to specific elements. Example: <html lang="en"> with <span lang="fr">Bonjour</span>. For separate language versions, use different URLs with proper hreflang annotations to help search engines serve the right version to users.
en (minimal), en-US (language + region), zh-Hant-CN (language + script + region). Tags are case-insensitive but conventionally use lowercase for language and uppercase for region.
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