Quick Diagnosis
Loopback means the server is the client. Browser success does not prove server-to-self requests work.
Problem
WordPress Loopback Request Failed
Diagnose loopback request failures by checking local HTTP requests, SSL redirects, basic auth, DNS, firewall rules, and cron-dependent workflows.
Problem
WordPress cannot make an HTTP request back to its own site.
For: Administrators seeing loopback warnings in Site Health or plugin diagnostics.
Workflow
What to review
Common Trap
Password protection, CDN rules, and SSL redirects can block loopback without breaking ordinary visitors.
WordPress AdminSeverity: MediumLast reviewed: 2026-09-16
Diagnosis
Symptoms, causes, checks, and fixes
Symptoms
- Site Health reports loopback request failed.
- Scheduled actions, cron tests, or plugin scans may fail.
- The site works in a browser but fails server-to-self HTTP checks.
Most Common Causes
- Firewall blocks self-requests.
- Broken SSL redirect.
- Basic auth or maintenance mode.
- DNS resolves differently from the server.
- Host blocks loopback requests.
How To Confirm The Cause
- Check the reported status code and error message.
- Review CDN/firewall rules for the server IP.
- Ask hosting whether loopback requests are allowed.
Fixes
- Allow server-to-site requests through firewall/CDN rules.
- Correct SSL and canonical redirects.
- Disable staging password protection for tests only when safe.
How To Verify The Fix
- Re-run Site Health.
- Confirm cron-dependent plugin tasks run.
- Check logs for successful self-request responses.
When To Contact Support
Contact hosting support when network-level loopback requests are blocked or DNS differs from expected public resolution.
References