How many websites pass the Lang check?

Based on 499 audited sites · Updated 2026-05-08

91.2%of audited sites pass this check↓0.3% vs last month

95% confidence interval: 88.4%–93.4%

About This Check

The HTML lang attribute helps AI systems understand the content language for proper localization and response generation.

Why This Matters

LLM Discoverability

The HTML lang attribute allows AI systems to route page content to the correct language model and apply appropriate tokenisation and summarisation pipelines for the language in question.

SEO Impact

The lang attribute is a prerequisite for hreflang to function correctly in multilingual setups, and it influences language-specific ranking in localised search markets.

Status Breakdown

91.2%pass(455)

8.8%warn(44)

0%fail(0)

Compliance Trend

Daily pass rate across benchmark snapshots (up to 90 days).

Industry Breakdown

How different industries perform on this check.

Other85.7% passavg score 67.4n=7

Energy100% passavg score 73.7n=3

Gaming100% passavg score 79.3n=3

Retail100% passavg score 77.2n=5

Travel83.3% passavg score 72n=6

Finance96.2% passavg score 75.7n=26