infoWordPress CoreerrorerrorlooploopbackcodecURLapiapischedulecronlabelCommonwarningModerate

The loopback request to your site failed

WordPress tries to contact itself to run scheduled tasks and check the REST API. The request stops when the server cannot reach the site URL. This happens because of network blocks, mis‑configured URLs, or PHP limits. When the request fails, WordPress reports the loopback error in Site Health.

The failure prevents cron jobs, automatic updates, and API calls from running. It also shows admin notices that the site could not complete a loopback request.

Symptoms

[dashicons-warning]
Site Health warning
Dashboard shows “Your site couldn’t complete a loopback request.”
[dashicons-admin-site]
Scheduled tasks stop
Posts scheduled for future publishing never appear, backups fail, updates do not run.
[dashicons-admin-network]
REST API errors
Site Health lists “The REST API encountered an unexpected result.”
[dashicons-admin-tools]
Plugin notices
Jetpack, backup tools, and other background plugins display error messages.

Common Causes

cURL configuration
Outdated PHP cURL version, missing SSL support, or wrong curl.cainfo leads to time‑outs.
Blocked internal request
Firewall or security plugin denies requests to wp‑cron.php or the REST API.
Incorrect Site URL
Typo or protocol mismatch in WP_HOME or WP_SITEURL builds a bad loopback URL.
PHP limits
Low max_execution_time, low memory_limit, or disabled allow_url_fopen stops the request.
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