How To Fix WordPress RSS Feed Errors

RSS feeds are published using the XML markup language. A single extra character (an invisible space, a stray tab, or even a byte order mark from a poorly saved file) can break the entire feed. When that happens, RSS readers stop pulling new content, and visitors using feed aggregators won’t see new posts.

You can check your feed directly in a browser by visiting yourdomain.com/feed (for the main blog feed) or yourdomain.com/feed/rss2. If the feed is working, the browser will display raw XML. If it’s broken, you’ll see an error like:

XML Parsing Error: XML or text declaration not at start of entity

Other common symptoms include:

• Feed readers reporting “feed not found” or returning empty results
• The feed URL returning a blank white page
• WordPress plugins that rely on your RSS feed (like feed-to-email tools) failing to send updates
• Podcast directories like Apple Podcasts or Spotify rejecting your feed during submission

Other apps and services also rely on the WordPress RSS feed, including some email newsletter plugins, content aggregators, and social sharing automations. When the feed breaks, all of these stop working too.

Several things can break a WordPress RSS feed, and the frustrating part is that most of them are invisible. The most common causes:

Extra whitespace or line breaks: A space or blank line before or after a PHP opening or closing tag in a theme or plugin file outputs characters before WordPress can send the XML headers. XML is unforgiving about this.

Byte order mark (BOM): Some code editors add a BOM character at the start of PHP files when saving. This invisible character appears before the XML declaration and breaks the feed. Windows Notepad is the most common culprit.

To check for a BOM and remove it: in Notepad++, open the file and look at the bottom right corner of the editor. If it reads “UTF-8-BOM”, go to Encoding > Convert to UTF-8 (without BOM) and save. In VS Code, click the encoding indicator in the status bar at the bottom right and select “Save with Encoding > UTF-8”. On Mac, most modern editors (TextMate, Nova, BBEdit) show the encoding in the status bar and let you switch with one click.

PHP output buffering issues: Certain plugins or theme functions print content to the page before WordPress sends the feed headers. This causes the XML declaration to appear mid-document rather than at the start.

Plugin conflicts: Plugins that modify content output (SEO plugins, social share plugins, custom post type plugins) can interfere with the feed format.

Theme code errors: A custom theme function that hooks into wp_head or outputs content early can corrupt the feed.

To get useful error information, open the feed URL in Firefox. Firefox renders XML and displays the exact line number and column of the error, which makes it much easier to trace the source.

The most common source of RSS errors is extra output before the XML declaration. Here’s how to track it down and fix it.

Fix 1: Check functions.php for extra whitespace

Open your theme’s functions.php file via FTP or the WordPress file editor (Appearance > Theme File Editor). Scroll to the very end of the file. If there is anything after the closing ?> PHP tag, even a blank line, delete it. Better yet, remove the closing PHP tag entirely. PHP doesn’t require it, and leaving it out eliminates the risk of trailing whitespace causing issues.

Fix 2: Add output buffering to functions.php

If the whitespace source is hard to find, you can prevent it from reaching the feed by adding output buffering. Add this code to the top of your functions.php file, immediately after the opening <?php tag:

ob_start();

This captures all output before WordPress sends the headers, which prevents stray characters from reaching the feed.

Fix 3: Refresh permalinks

Sometimes the feed breaks after a permalink structure change. Go to Settings > Permalinks in your WordPress admin and click Save Changes without changing anything. This flushes the rewrite rules and often resolves feed 404 errors.

Validate your feed

After making any fix, validate the feed at the W3C Feed Validation Service. Paste your feed URL and run the check. It will tell you whether the feed is valid XML and flag any remaining issues.

If the manual fix above didn’t solve the problem, a plugin is likely generating extra output that’s corrupting the feed. Here’s how to find it efficiently.

The naive approach is deactivating all plugins at once and then reactivating them one at a time. But if you have 20 plugins, that’s 20 tests. A faster method is binary search:

1. Deactivate half of your active plugins
2. Check the feed. If it works, the problem is in the half you just deactivated. If it’s still broken, the problem is in the other half.
3. Take the problematic half and deactivate half of those
4. Repeat until you’ve identified the single plugin causing the issue

This typically finds the culprit in 4-5 tests regardless of how many plugins you have.

Look first at plugins that modify output or content: SEO plugins, social sharing plugins, analytics plugins, and any plugin that hooks into wp_head or wp_footer. These are the most common offenders.

Once you’ve found the culprit, check whether the plugin has a settings option that’s generating the extra output. Sometimes disabling a specific plugin feature (rather than the whole plugin) is enough to fix the feed.

If disabling plugins didn’t fix the feed, your theme is the next suspect. The safest way to test this is to temporarily switch to a default WordPress theme like Twenty Twenty-Four.

Go to Appearance > Themes and activate a default theme. Then check the feed again. If the feed works with the default theme, your original theme has code that’s corrupting the feed output.

One important note: if you’re using a child theme, test the child theme and the parent theme separately. Deactivating the child theme and switching back to the parent theme alone can help you pinpoint whether the problem is in the parent theme’s functions.php or in your child theme customizations.

If the theme is confirmed as the cause:

• Contact the theme developer and report the issue. Provide the XML error message and the URL of your feed. Most quality theme developers will fix this quickly.
• Check the theme’s support forum or changelog. The fix may already be available in an update.
• If the developer is unresponsive or the theme is abandoned, it’s worth looking for a replacement. You can use our guide to installing a new WordPress theme to make the switch safely.

Sometimes your RSS feed URL returns valid XML but feed readers report stale content, show no new posts, or the feed appears to serve the wrong content type. This is different from a broken feed. The URL works, but your cache layer is serving an outdated version or blocking the correct response headers.

This happens most often after installing a new caching plugin or switching to a CDN like Cloudflare.

Clear your caching plugin’s cache first:
Most caching plugins add a “Clear All Cache” button to the WordPress admin toolbar. Clear the cache and immediately check your feed URL in a browser. If fresh posts now appear, caching was the issue.

To prevent it from recurring, exclude the feed URL from caching:

• WP Rocket: Go to Settings > WP Rocket > Cache and add /feed/ to the “Never Cache URL(s)” field.
• W3 Total Cache: Go to Page Cache > Advanced and add /feed/ to the “Never cache the following pages” list.
• LiteSpeed Cache: Go to LiteSpeed Cache > Cache > Excludes and add /feed to the URI field.
• WP Super Cache: Go to Settings > WP Super Cache > Advanced and add feed to the “Reject URI” list.

Cloudflare users:
Cloudflare caches static assets by default, and some configurations cache dynamic pages including your feed URL. Log in to your Cloudflare dashboard, go to Caching > Cache Rules, and check for any rules that might affect /feed/.

Try purging the cache for your feed URL specifically: go to Caching > Configuration > Custom Purge and enter your feed URL. If purging fixes it temporarily but the problem returns, set up a Cache Rule to bypass caching for all URLs containing /feed.

Quick test to confirm caching is the cause:
Add a unique query string to your feed URL (yourdomain.com/feed/?nocache=1) and check whether new posts appear. If the feed works with the query string but not without, caching is the issue.