HTML Guide
The web page could not be validated because it took too long for the remote server to respond.
A table row tr has been found, containing no td cells. Check the table and remove empty rows.
Table contents is organized in rows using the <tr> element, which must contain cells using the <td> element, as in this example:
<table>
<thead>
<tr>
<th>Name</th>
<th>Age</th>
</tr>
</thead>
<tbody>
<tr>
<td>Liza</td>
<td>12</td>
</tr>
<tr>
<td>Jimmy</td>
<td>14</td>
</tr>
</tbody>
</table>A tr with no td cells on it will raise an issue, as in this example:
<table>
<thead>
<tr>
<th>Name</th>
<th>Age</th>
</tr>
</thead>
<tbody>
<tr>
</tr>
<tr>
<td>Jimmy</td>
<td>14</td>
</tr>
</tbody>
</table>Note that self-closing <tr/> elements also count as empty rows as are like <tr></tr>.
An end tag has been found after the closing </body> tag, which breaks the expected HTML document structure.
Check out the document structure, a basic example follows:
<!DOCTYPE html>
<html lang="">
<head>
<title>Test</title>
</head>
<body>
<p></p>
</body>
</html>Attributes for HTML elements must be defined like name="value". The name may be missing before the =.
Some examples:
<!-- Missing equal sign -->
<p name "value"></p>
<!-- Missing space before the attribute -->
<pname "value"></p>A < character has been found when an attribute was expected instead. Check the syntax of the affected tag, it’s probably malformed and a < character inside has been interpreted as an attribute.
For example, this code might cause this issue:
<!-- Malformed img tag -->
<img src="photo.jpg" alt="smiling cat" < />
<!-- Fixed img tag -->
<img src="photo.jpg" alt="smiling cat" />A tag starting with <? has been found within the document, but it’s not supported. Probable causes can be:
- Copy-pasting the contents of an SVG file. If you do that, you should only paste the <svg>...</svg> part, but not the first line with <?xml...>.
- Unprocessed <?...> tags on server scripting languages like PHP, like <?php>
Learn more:
- [freeCodeCamp: How to Use SVG Images in CSS and HTML]https://www.freecodecamp.org/news/use-svg-images-in-css-html/)
Ensure to escape unescaped angle brackets by using < for < and > for > in HTML.
HTML documents may contain special characters where using the raw characters could lead to errors or misinterpretation by the browser. This is common with angle brackets < and >, which are used for delimiting HTML tags. If these characters are used in textual content or mistakenly typed in an unintended manner, it can cause issues, such as unexpected tag closure or rendering problems.
In your case, the W3C HTML Validator has detected an occurrence of the characters </> which might actually be intended as a simple display of these symbols, but are misinterpreted as an incomplete HTML tag. To prevent such issues, you should escape these characters using HTML character entities like < for the less-than sign and > for the greater-than sign.
Example:
You might want to display code or a message like This is the “<tag>” example in your HTML content. The direct use of < and > can break the HTML content. Instead, use:
<p>This is the "<tag>" example.</p>If you are trying to display the stand-alone sequence </>, you should use:
<p>Saw “</>”</p>These replacements ensure the validator processes your HTML correctly without mistaking your intended display content for HTML coding errors.
Attributes for HTML elements must be defined like name="value". A common issue is missing the =, or repeating the " like in these examples:
<!-- Missing equal sign -->
<p name "value"></p>
<!-- Repeated quotes -->
<p name="value""></p>Nested comments are not allowed in HTML. When you place an opening comment tag <!-- within an existing comment, it causes a parsing error.
To fix this issue, you should avoid nesting comments. If you need to include multiple comments in your HTML code, you can separate them or consider alternative ways to convey the information without nested comments.
Here’s an example of a nested comments, which is not allowed in HTML:
<!-- This is a valid comment -->
<!-- This <!-- is not allowed --> nested comment -->To fix the nested comment issue, you can rewrite the comments like this:
<!-- This is a valid comment -->
<!-- Avoid nesting comments and provide comments separately -->
<!-- Another comment here --> The <section> element can be used to define sections of a document, like chapters, tabbed content, etc. Consider using a heading element (any of <h2> to </h6>) to present each section. Example:
<h1>All about guitars</h1>
<section>
<h2>Guitar types</h2>
<p>Acoustic, electric, classical... we have them all!</p>
</section>
<section>
<h2>Amplifiers</h2>
<p>Analog, digital, portable...</p>
</section>A slash character (/), normally used for self-closing tags, has been found in an unexpected place for a tag, and the validator has decided to ignore it and treat is as a start tag instead.
HTML tags can go in pairs (start tag, end tag) or be self-closing, for example:
<p>This is a paragraph with a start and end p tag</p>
<img src="image.jpg" alt="This is an image with a self-closing tag" />In HTML5, the ending slash and the preceding space is optional for self-closing tags so all of these are valid:
<img src="image.jpg" alt="This is an image with a self-closing tag" />
<img src="image.jpg" alt="This is an image with a self-closing tag"/>
<img src="image.jpg" alt="This is an image with a self-closing tag">A common mistake is including a slash tag on a start tag, as in the following example. If the Nu HTML checker encounters that, it will ignore the slash and just treat the tag as a start tag.
<select />
<option value="1">one</option>
</select>An <a> tag can’t include other <a> tags inside. Most probable cause is an unclosed <a> tag, like in this example:
<a href="one.html">Page 1
<a href="two.html">Page 2</a>An <a> element has been found in an invalid place within a <table> element.
For example, the following code would cause this issue:
<table>
<tr>
<a href="#">link</a>
</tr>
</table>Instead, the <a> element should be inside a <td> element, as a <tr> can’t hold content directly:
<table>
<tr>
<td>
<a href="#">link</a>
</td>
</tr>
</table>An opening <body> tag has been found in an incorrect place. Check that it appears only once in the document, right after the closing </head> tag, and that the whole document content is contained within <body> and </body> tags.
A <br> element has been found in an invalid place within a <table> element.
For example, the following table has an invalid <br> between two <tr>, but the <br> that appears inside a <td> is valid.
<table>
<tr>
<th>Item</th>
<th>Description</th>
</tr>
<!-- The following br is invalid -->
<br>
<tr>
<td>Book</td>
<td>
<!-- The br in the following line is valid -->
Title: HTML & CSS<br>
Author: John Duckett
</td>
</tr>
</table>A <button> tag can’t include other <button> tags inside. Most probable cause is an unclosed <button> tag, like in this example:
<button>Submit
<button>Cancel</button>An opening <head> tag has been found in an incorrect place. Check that there’s only a <head> tag in the document.
This issue can happen because the expected closing tag </head> was misspelled as <head>, as in this example:
<!DOCTYPE html>
<html lang="">
<head>
<title>Test</title>
<head>
<body>
</body>
</html>Or, it could happen because another <head>...</head> section was nested inside a previous one:
<!DOCTYPE html>
<html lang="">
<head>
<title>Test</title>
<head>
</head>
</head>
<body>
</body>
</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>All HTML documents must start with a <!DOCTYPE> (Document Type Declaration), that informs browsers about the type and version of HTML used to build the document. In HTML5, this is simply <!DOCTYPE html> and must appear at the start of the document.
Here is an example of a minimal HTML document, including the Document Type Declaration at its start:
<!DOCTYPE html>
<html>
<head>
<title>Test</title>
</head>
<body>
<p></p>
</body>
</html>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>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>A stray start tag <html> has been found in the document. As this tag defines the start of the whole HTML document, it should appear only once.
The “Stray start tag noscript“ error in the W3C HTML Validator indicates that the <noscript> tag has been used incorrectly or is placed in an invalid location within your HTML document.
The <noscript> tag is used to define alternative content for users who have disabled JavaScript in their browsers or for browsers that do not support JavaScript.
Common Causes:
- Position of <noscript>: The <noscript> tag should be placed correctly within sections where it is allowed.
- Nested Improperly: The <noscript> tag should not be placed inside other tags where it is not valid.
Correct Usage:
-
Within <head>:
<head> <title>Example Page</title> <script> // Some JavaScript code </script> <noscript> <style> /* Alternative styling if JavaScript is disabled */ </style> </noscript> </head> -
Within <body>:
<body> <h1>Welcome to the Example Page</h1> <script> // Some JavaScript code </script> <noscript> <p>JavaScript is disabled in your browser. Please enable JavaScript for the full experience.</p> </noscript> </body>
Fixing the Issue:
-
Inside Existing Tags: Ensure the <noscript> tag is not placed inside other tags where it cannot be parsed correctly.
<!-- Incorrect --> <div> <noscript> <p>JavaScript is disabled in your browser.</p> </noscript> </div> <!-- Correct --> <noscript> <div> <p>JavaScript is disabled in your browser.</p> </div> </noscript> -
Placement in Body or Head: Verify that the <noscript> tag is placed inside the <body> or <head> based on what content it’s providing a fallback for.
<!-- Incorrect (inside an illegal tag) --> <div> Some content <noscript><p>JavaScript is disabled in your browser.</p></noscript> </div> <!-- Correct --> <div>Some content</div> <noscript><p>JavaScript is disabled in your browser.</p></noscript>
Summary:
- Place <noscript> only within accepted sections (<head> or <body>).
- Avoid nesting <noscript> inside other tags improperly.
A <script> start tag has been found in an unexpected place in the document structure. Check that the <script> section appears within the <head> or <body> sections.
Here’s an example of a script inserted in the head of the document:
<!DOCTYPE html>
<html>
<head>
<title>Test</title>
<script>
console.log("Hello from the head");
</script>
</head>
<body>
<p></p>
</body>
</html>The “Stray start tag “section”” error in the W3C HTML Validator typically occurs when a <section> tag appears in an unexpected location within your HTML document structure. This can happen if the <section> tag is not positioned correctly within the HTML5 content model.
Here’s a focused guide to fix this issue:
1. Check the Parent Element
Make sure the <section> tag is placed within elements where it is allowed. According to the HTML5 specification:
- A <section> element should be placed within the <body> tag.
- It should not be a direct child of an inline element or an element that does not support flow content.
2. Correct Nesting Within Elements
Ensure your HTML structure follows a logical hierarchy and that the <section> element is not incorrectly nested. This example shows a correct usage of the <section> tag:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Correct Usage of Section</title>
</head>
<body>
<header>
<h1>Page Title</h1>
</header>
<nav>
<!-- Navigation links -->
</nav>
<main>
<section>
<h2>Section Title</h2>
<p>Content for the first section.</p>
</section>
<section>
<h2>Another Section Title</h2>
<p>Content for the second section.</p>
</section>
</main>
<footer>
<p>Footer content</p>
</footer>
</body>
</html>3. Check for Mistaken Hierarchy
Verify whether the <section> tag is mistakenly placed inside elements that do not support it, such as directly inside a <p> tag or other inline elements. Correct any incorrect usage. For example this is incorrect usage because the <section> tag is placed after the closing <body> tag:
Incorrect:
<!DOCTYPE html>
<html lang="en">
<head>
<title>Sample page</title>
</head>
<body>
<h1>Main title</h1>
<p>Some content</p>
</body>
</html>
<section>
<h2>Incorrect Section</h2>
<p>This section should not be after the closing body tag.</p>
</section>Correct:
<!DOCTYPE html>
<html lang="en">
<head>
<title>Sample page</title>
</head>
<body>
<h1>Main title</h1>
<p>Some content</p>
<section>
<h2>Correct Section</h2>
<p>This section is fine.</p>
</section>
</body>
</html>
Summary
- Ensure your <section> tags are used within the <body> tag and other allowed elements.
- Maintain a logical hierarchy in your HTML document.
- Avoid placing <section> tags inside inline elements like <p>.
Following these steps should resolve the “Stray start tag “section”” error in your HTML document. Validate your HTML again after making these corrections to ensure the issue is resolved.