Linter Rule: Duplicate `<meta>` name attributes are not allowed

Rule: html-no-duplicate-meta-names

Description

Warn when multiple <meta> tags share the same name or http-equiv attribute within the same <head> block, unless they are wrapped in conditional comments.

Rationale

In HTML, duplicate <meta> tags with the same name or http-equiv can cause unexpected behavior. For example, search engines or social sharing tools may use the wrong value. These duplicates are often the result of copy-paste or partial rendering logic and should be avoided.

Examples

✅ Good

erb

<head>
  <meta name="description" content="Welcome to our site">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
</head>

erb

<head>
  <% if mobile? %>
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <% else %>
    <meta name="viewport" content="width=1024">
  <% end %>
</head>

🚫 Bad

erb

<head>
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta name="viewport" content="width=1024">Duplicate `<meta>` tag with `name="viewport"`. Meta names should be unique within the `<head>` section. (html-no-duplicate-meta-names)
</head>

erb

<head>
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta http-equiv="X-UA-Compatible" content="chrome=1">Duplicate `<meta>` tag with `http-equiv="X-UA-Compatible"`. `http-equiv` values should be unique within the `<head>` section. (html-no-duplicate-meta-names)
</head>

erb

<head>
  <meta name="viewport" content="width=1024">

  <% if mobile? %>
    <meta name="viewport" content="width=device-width, initial-scale=1.0">Duplicate `<meta>` tag with `name="viewport"`. Meta names should be unique within the `<head>` section. (html-no-duplicate-meta-names)
  <% else %>
    <meta http-equiv="refresh" content="30">  
  <% end %>
</head>

Linter Rule: Duplicate <meta> name attributes are not allowed ​

Description ​

Rationale ​

Examples ​

✅ Good ​

🚫 Bad ​

References ​