HTML check: Stray doctype. · Rocket Validator

Almost standards mode doctype. Expected “<!DOCTYPE html>”.

End of file seen without seeing a doctype first. Expected “<!DOCTYPE html>”.

HTML documents are expected to start with a first line containing the Document Type Declaration, that defines the HTML version used. Since HTML5, it’s just <!DOCTYPE html>, which must appear before the start <html> tag.

Here’s an example of a minimal HTML5 document:

<!DOCTYPE html>
<html>
  <head>
    <title>Test</title>
  </head>
  <body>
    <p></p>
  </body>
</html>

Non-space characters found without seeing a doctype first. Expected “<!DOCTYPE html>”.

A missing or incorrectly placed <!DOCTYPE html> declaration at the very start of your HTML document causes this error.

The <!DOCTYPE html> declaration must be the very first thing in your HTML file, before any HTML code. This declaration tells the browser to use standards mode, ensuring reliable rendering. Without it, browsers may behave unpredictably or trigger quirks mode, and validators will issue an error.

Correct Example:

<!DOCTYPE html>
<html lang="en">
  <head>
    <title>Valid HTML Document</title>
  </head>
  <body>
    <p>Hello, world!</p>
  </body>
</html>

Incorrect Example (doctype missing):

<html lang="en">
  <head>
    <title>Invalid HTML Document</title>
  </head>
  <body>
    <p>Hello, world!</p>
  </body>
</html>

Incorrect Example (doctype not at the very start):

Some misplaced text.

<!DOCTYPE html>
<html lang="en">
  <head>
    <title>Invalid Placement</title>
  </head>
  <body>
    <p>Hello, world!</p>
  </body>
</html>

Always ensure <!DOCTYPE html> is the first line.

Obsolete doctype. Expected “<!DOCTYPE html>”.

Quirky doctype. Expected “<!DOCTYPE html>”.

doctype
html

The <!DOCTYPE html public "-//W3C//DTD HTML 4.0 Transitional//EN"> doctype triggers quirks mode in modern browsers and is not compliant with HTML5 standards.

The HTML5 specification requires the use of a simple doctype declaration, which ensures standards mode rendering. The correct doctype is <!DOCTYPE html>, which must appear at the very top of every HTML5 document. Legacy doctypes like HTML 4.0 Transitional are obsolete for modern web development and can cause inconsistent browser behavior.

Example of correct usage:

<!DOCTYPE html>
<html lang="en">
  <head>
    <title>Valid HTML5 Doctype Example</title>
  </head>
  <body>
    <p>Your content here.</p>
  </body>
</html>

Replace any legacy or malformed doctype with the above declaration to conform to current HTML standards.

Start tag seen without seeing a doctype first. Expected “<!DOCTYPE html>”.

HTML documents are expected to start with a first line containing the Document Type Declaration, that defines the HTML version used. Since HTML5, it’s just <!DOCTYPE html>, which must appear before the start <html> tag.

Here’s an example of a minimal HTML5 document:

<!DOCTYPE html>
<html>
  <head>
    <title>Test</title>
  </head>
  <body>
    <p></p>
  </body>
</html>

Stray end tag “X”.

An end tag for X has been found that does not correspond to a previous open tag. This usually happens when you close the same tag twice, for example:

<ul>
  <li>item</li>
</ul>
</ul>

Stray start tag “br”.

A stray <br> happens when the <br> element, which is phrasing content, is placed in contexts that only allow specific children. Common mistakes include putting <br> directly inside <ul>, <ol>, <table>, <tr>, or outside <body>, and inserting it between block-level siblings to add spacing instead of using CSS. The validator flags this because it violates the HTML content model.

This matters for standards compliance, predictable rendering, and accessibility. Screen readers and assistive tech rely on correct structure (lists made of li, tables built from tr/td, sections within body). Misplaced <br> can produce confusing reading orders and inconsistent layout across browsers.

How to fix:

Keep <br> only where phrasing content is allowed (typically inside text-flowing elements like p, span, li, td, caption).
For spacing between blocks, use CSS margins instead of <br>.
For lists, use proper li items; for tables, place text inside td/th; for forms, use grouping and CSS.
Ensure no <br> appears outside <body> or inside elements that have restricted content models (ul, ol, table, tr, thead, tbody, tfoot, colgroup, select, dl directly, etc.).
If a line break is purely presentational across viewports, consider CSS (display:block, white-space) instead of <br>.

Examples

Valid use inside phrasing content

<p>
  First line.<br>
  Second line.
</p>

Invalid: <br> directly inside a list (triggers the error)

<ul>
  <br>
  <li>Item 1</li>
  <li>Item 2</li>
</ul>

Fix: remove the stray <br>; use list items only

<ul>
  <li>Item 1</li>
  <li>Item 2</li>
</ul>

Invalid: <br> outside <body> (triggers the error)

<!DOCTYPE html>
<html lang="en">
<head>
  <title>Stray br Tag Example</title>
</head>
<br>
<body>
  Content here.
</body>
</html>

Fix: move <br> inside the body (or use CSS if only spacing is needed)

<!DOCTYPE html>
<html lang="en">
<head>
  <title>No Stray br Tag</title>
</head>
<body>
  Content here.<br>
  New line in body.
</body>
</html>

Invalid: <br> as a child of <table> (triggers the error)

<table>
  <br>
  <tr>
    <td>A</td>
    <td>B</td>
  </tr>
</table>

Fix: use proper table rows and cells; place text inside cells

<table>
  <tr>
    <td>A</td>
    <td>B</td>
  </tr>
  <tr>
    <td>More A</td>
    <td>More B</td>
  </tr>
</table>

Invalid: using <br> for spacing between blocks (not allowed between siblings)

<div>Section A</div>
<br>
<div>Section B</div>

Fix: use CSS margins for spacing

<!DOCTYPE html>
<html lang="en">
<head>
  <title>Spacing with CSS</title>
  <style>
    .block { margin-bottom: 1rem; }
  </style>
</head>
<body>
  <div class="block">Section A</div>
  <div>Section B</div>
</body>
</html>

Valid alternatives where a break is needed in phrasing context

<li>
  Address: 123 Main St.<br>
  Suite 400
</li>

Tips:

Use exactly <br> (no closing tag needed) and do not self-close as XML (<br />) unless your tooling requires it; both parse in HTML, but stick to HTML style for consistency.
If you see multiple “stray start tag ‘br’” errors, check parent containers: fixing the first invalid parent often resolves many subsequent errors.

Stray start tag “div”.

A <div> tag appears where the HTML structure does not expect it, often due to incorrect nesting or missing closing tags.

HTML elements must be properly nested and closed according to the specifications outlined by the HTML standard. A stray start tag usually occurs when a block-level element like <div> is used in a context where only phrasing (inline) content is permitted, or if required closing tags (such as </li>, </tr>, or </td>) are missing, causing the parser to be out of sync.

Incorrect Example: div after closing the html tag

<!DOCTYPE html>
<html lang="">
<head>
<title>Test</title>
</head>
<body>
<p></p>
</body>
</html>
<div>
  some extra content
</div>

In the above, the <div> at the bottom is not valid because it appears after closing the html tag.

Always close elements properly and place block-level elements like <div> only inside appropriate containers. If your issue occurs elsewhere, look for missing closing tags or incorrect placement of the <div> relative to tables, lists, or other structural elements.

Stray start tag “head”.

A <head> start tag has been found in an unexpected place in the document structure. Check that the <head> section appears before the <body> section, and that is not duplicated.

The <head> section of an HTML document is the container of metadata about the document, and must appear before the <body> section. A common cause of this issue is duplicated <head> sections.

Here is an example of a minimal HTML document structure:

<!DOCTYPE html>
<html>
  <head>
    <title>Test</title>
  </head>
  <body>
    <p></p>
  </body>
</html>

HTML Guide

Stray doctype.

Related W3C validator issues