doctype 🔧

Require DOCTYPE declaration.

Severity

error

❌ Incorrect

<html lang="en"><head><title>T</title></head><body><h1>T</h1></body></html>

✅ Correct

<!DOCTYPE html>
<html lang="en"><head><title>T</title></head><body><h1>T</h1></body></html>

Reference

• HTML Standard - The DOCTYPE

Configuration

{
  "rules": {
    "doctype": "error"
  }
}