About This HTML Issue
The lang attribute on the <html> element declares the primary language of the document’s content. When this attribute is left empty (lang=""), it effectively tells browsers and assistive technologies that the language is unknown or intentionally unspecified — which is almost never what you want.
This matters for several important reasons:
-
Accessibility: Screen readers rely on the
langattribute to select the correct pronunciation engine. An empty value can cause a screen reader to fall back to a default language, potentially reading English text with incorrect pronunciation rules. -
Search engines: Search engines use the
langattribute to understand what language your content is in, which helps serve your pages to the right audience. - Browser features: Browsers use the language declaration for hyphenation, spell-checking, font selection, and other language-sensitive rendering decisions.
-
Standards compliance: The WHATWG HTML living standard specifies that if the
langattribute is present, its value must be a valid BCP 47 language tag. An empty string is not a valid language tag.
The fix is straightforward: set the lang attribute to a valid BCP 47 language tag that matches your content. For English, common values include en (general English), en-US (American English), or en-GB (British English). If your content is in another language, use the appropriate tag (e.g., fr for French, de for German, ja for Japanese).
Examples
❌ Empty lang attribute (triggers the warning)
<!DOCTYPE html>
<html lang="">
<head>
<title>My Page</title>
</head>
<body>
<h1>Welcome to my website</h1>
</body>
</html>
❌ Missing lang attribute entirely
While a missing lang attribute triggers a different warning, it causes the same underlying problem — no language is declared:
<!DOCTYPE html>
<html>
<head>
<title>My Page</title>
</head>
<body>
<h1>Welcome to my website</h1>
</body>
</html>✅ Correct: specifying the language
<!DOCTYPE html>
<html lang="en">
<head>
<title>My Page</title>
</head>
<body>
<h1>Welcome to my website</h1>
</body>
</html>✅ Correct: using a regional variant
<!DOCTYPE html>
<html lang="en-US">
<head>
<title>My Page</title>
</head>
<body>
<h1>Welcome to my website</h1>
</body>
</html>
Using lang for mixed-language content
If your document is primarily in English but contains sections in other languages, set lang="en" on the <html> element and override it on specific elements:
<!DOCTYPE html>
<html lang="en">
<head>
<title>Multilingual Page</title>
</head>
<body>
<h1>Welcome</h1>
<p>This page contains a quote in French:</p>
<blockquote lang="fr">
<p>La vie est belle.</p>
</blockquote>
</body>
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