RSS Validator

Common RSS Feed Errors

How to Identify and Fix Them

RSS feed errors can prevent your content from reaching subscribers and being indexed by aggregators. This guide covers the most common RSS validation errors with clear explanations and code examples showing how to fix each issue.

Top 10 RSS Feed Errors & Solutions

#1XML Parsing Error: Mismatched Tags

This error occurs when opening and closing XML tags do not match. XML is strict about tag names being identical.

❌ Incorrect:

<item>
  <title>My Article</Title>  <!-- Wrong: 'Title' != 'title' -->
</item>

✓ Correct:

<item>
  <title>My Article</title>  <!-- Correct: matching tags -->
</item>

💡 Fix: Ensure all opening tags have matching closing tags with identical casing. XML is case-sensitive.

RSS requires dates in RFC 822 format. Using ISO 8601 or other formats will cause parsing issues in feed readers.

❌ Incorrect:

<pubDate>2024-01-15T12:00:00Z</pubDate>  <!-- Wrong: ISO 8601 format -->
<pubDate>January 15, 2024</pubDate>      <!-- Wrong: Human-readable format -->

✓ Correct:

<pubDate>Mon, 15 Jan 2024 12:00:00 GMT</pubDate>  <!-- Correct RFC 822 -->
<pubDate>Mon, 15 Jan 2024 12:00:00 +0000</pubDate> <!-- Also valid -->

💡 Fix: Use RFC 822 date format: "Day, DD Mon YYYY HH:MM:SS TIMEZONE". Include the timezone (GMT or +0000).

XML has reserved characters (<, >, &, ", ') that must be escaped or wrapped in CDATA sections to avoid parsing errors.

❌ Incorrect:

<title>Tom & Jerry</title>        <!-- Wrong: unescaped & -->
<title>Price: $5 < $10</title>   <!-- Wrong: unescaped < -->

✓ Correct:

<title>Tom &amp; Jerry</title>   <!-- Correct: escaped & -->
<title><![CDATA[Price: $5 < $10]]></title>  <!-- Correct: CDATA section -->

💡 Fix: Escape special characters: & → &amp;, < → &lt;, > → &gt;, " → &quot;. Or use CDATA sections for complex content.

RSS 2.0 requires specific elements at the channel level. Missing these will cause validation failures.

❌ Incorrect:

<channel>
  <item>
    <title>My Post</title>
  </item>
</channel>
<!-- Missing: title, link, description -->

✓ Correct:

<channel>
  <title>My Website</title>
  <link>https://example.com</link>
  <description>My website description</description>
  <item>
    <title>My Post</title>
  </item>
</channel>

💡 Fix: Include all required channel elements: <title>, <link>, and <description>.

URLs in RSS feeds must be absolute and properly formatted. Relative URLs and spaces cause issues.

❌ Incorrect:

<link>/posts/my-article</link>           <!-- Wrong: relative URL -->
<link>https://example.com/my article</link>  <!-- Wrong: unencoded space -->

✓ Correct:

<link>https://example.com/posts/my-article</link>  <!-- Correct: absolute URL -->
<link>https://example.com/my%20article</link>       <!-- Correct: encoded space -->

💡 Fix: Always use absolute URLs starting with http:// or https://. Encode special characters in URLs.

RSS feeds should have a proper XML declaration with the correct encoding to avoid character display issues.

❌ Incorrect:

<rss version="2.0">  <!-- Missing XML declaration -->
<!-- or -->
<?xml version="1.0" encoding="UTF-8"?>
<!-- But actual content is in ISO-8859-1 -->

✓ Correct:

<?xml version="1.0" encoding="UTF-8"?>
<rss version="2.0">
  <!-- Content is actually UTF-8 encoded -->

💡 Fix: Include the XML declaration with correct encoding. Ensure your server sends matching Content-Type header.

Each item in an RSS feed should have a unique GUID (Globally Unique Identifier). Duplicates confuse feed readers.

❌ Incorrect:

<item>
  <guid>post-1</guid>
  <title>First Post</title>
</item>
<item>
  <guid>post-1</guid>  <!-- Wrong: duplicate GUID -->
  <title>Second Post</title>
</item>

✓ Correct:

<item>
  <guid>https://example.com/posts/first-post</guid>
  <title>First Post</title>
</item>
<item>
  <guid>https://example.com/posts/second-post</guid>
  <title>Second Post</title>
</item>

💡 Fix: Use unique GUIDs for each item. URLs work well as GUIDs since they are naturally unique.

Media enclosures (for podcasts, images, etc.) require specific attributes: url, length, and type.

❌ Incorrect:

<enclosure url="https://example.com/audio.mp3" />
<!-- Missing: length and type attributes -->

✓ Correct:

<enclosure 
  url="https://example.com/audio.mp3" 
  length="12345678" 
  type="audio/mpeg" />

💡 Fix: Include all three required enclosure attributes: url, length (in bytes), and type (MIME type).

Using extended elements (like iTunes tags for podcasts) requires proper namespace declarations.

❌ Incorrect:

<rss version="2.0">
  <channel>
    <itunes:author>John Doe</itunes:author>  <!-- Error: undefined namespace -->

✓ Correct:

<rss version="2.0" 
  xmlns:itunes="http://www.itunes.com/dtds/podcast-1.0.dtd">
  <channel>
    <itunes:author>John Doe</itunes:author>  <!-- Works with namespace -->

💡 Fix: Declare namespaces in the root <rss> element before using prefixed elements.

HTML content in RSS elements must be wrapped in CDATA sections or entity-encoded.

❌ Incorrect:

<description>
  <p>Welcome to <strong>my blog</strong>!</p>
</description>
<!-- Parser sees <p> and <strong> as RSS elements -->

✓ Correct:

<description><![CDATA[
  <p>Welcome to <strong>my blog</strong>!</p>
]]></description>
<!-- HTML is treated as text content -->

💡 Fix: Wrap HTML content in CDATA sections: <![CDATA[ ... ]]>. This tells parsers to treat it as text.

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