WordPress automatically creates RSS feeds for posts, comments, categories and other content. Feed readers and automation tools may stop working when the XML is malformed, empty, redirected incorrectly or blocked.
Common symptoms include an XML parsing error, “Extra content at the end of the document,” a blank feed or an HTML error page instead of XML.
Open the default feed URL
Visit example.com/feed/ and confirm the response contains XML. Test in a private window so an authenticated session or cache does not affect the result. Category feeds normally use the category archive URL followed by /feed/.
Validate the feed
Use the W3C Feed Validation Service or another reputable validator. Record the first reported XML error and its line number. Later errors may be consequences of the first malformed character or tag.
Check for PHP warnings and fatal errors
A plugin or theme warning printed before the XML declaration will break the feed. Review PHP logs and disable public error display. WordPress debugging should write errors to a log instead of showing them to feed subscribers.
Remove whitespace before or after PHP tags
Extra spaces, blank lines or a byte-order mark in PHP files can send output before the feed begins. Check recently edited functions.php, custom plugins and WPCode snippets. PHP-only files generally should not include a closing ?> tag.
If recent custom code caused the problem, my WordPress syntax error guide provides a safe rollback process.
Test plugins and the active theme
SEO, feed, podcast, membership, translation and caching plugins can alter RSS output. Deactivate the most likely plugin, clear caches and test again. Use staging to disable plugins one at a time when the source is unclear.
Temporarily switch to a default theme on staging to identify theme-level feed modifications.
Refresh permalink rules
Go to Settings > Permalinks and click Save Changes. This refreshes rewrite rules without requiring a new permalink structure. If the feed URL returns a 404, also check server rewrite configuration.
Check caching and CDN behavior
Purge WordPress, server and CDN caches. Confirm the feed URL is not cached with an HTML error, redirected to a consent page or blocked by a firewall. Some optimization settings incorrectly minify or alter XML responses.
Review security rules
Security plugins and web application firewalls may block feed readers because they send frequent automated requests. Review logs for the requesting IP and user agent. Create a narrow exception only when the service is legitimate.
Check content that breaks XML
A single recent post may contain invalid characters, malformed shortcodes or plugin-generated markup that breaks the feed. Temporarily exclude or revert the newest post to test. Clean the source content instead of editing generated XML.
Confirm the correct content type
A healthy feed should return an XML content type rather than text/html. Redirect chains, maintenance pages and server errors can replace the feed response. Check the final URL and HTTP status.
Prevent future feed failures
- Keep PHP errors out of public output.
- Test feeds after theme or feed-plugin changes.
- Validate feeds used by important automations.
- Monitor feed URLs for non-200 responses.
- Use staging for custom feed code.
Feed problems can interrupt syndication and discovery. For related crawl and indexing issues, see my WordPress troubleshooting hub.
