503
5xxSEO: negativeRFC 9110
HTTP 503 Service Unavailable
The server is temporarily unavailable. With Retry-After, Googlebot will return later.
Indexable by Google
No
Link equity passed
No
SEO Impact
Negative
Category
5XX
SEO Impact
503 is the SEO-safe way to handle planned maintenance. Unlike 500/502, a 503 with a Retry-After header explicitly tells Googlebot to come back later without penalizing the site. Google will not deindex pages for short 503 periods if Retry-After is set. For extended maintenance (hours), Google recommends pairing 503 with a Retry-After of 1 hour or more. Sustained 503s (days) will eventually cause deindexing.
When to Use 503
Planned maintenance windows, database migrations, deployment downtime. Always set Retry-After.
HTTP Response Example
HTTP/1.1 503 Service Unavailable Retry-After: 3600 Content-Type: text/html
Test with cURL
$ curl -I https://example.com/