506 Variant Also Negotiates comes from Transparent Content Negotiation (RFC 2295), an experimental HTTP extension. It means the server has an internal configuration error: the variant chosen for the request is itself configured for content negotiation, so the negotiation would never end.
Transparent Content Negotiation never became widespread, and 506 is rare. Apache's mod_negotiation is the best-known implementation and can produce it when type maps or MultiViews point to resources that are negotiated themselves.
Example response
HTTP
HTTP/1.1 506 Variant Also Negotiates
Date: Fri, 06 Nov 2026 10:15:32 GMT
Server: Apache
Content-Type: text/html; charset=iso-8859-1
Content-Length: 283
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<html><head>
<title>506 Variant Also Negotiates</title>
</head><body>
<h1>Variant Also Negotiates</h1>
<p>A variant for the requested resource is itself a negotiable resource. This indicates a configuration error.</p>
</body></html>SEO and redirect checking
Like other 5xx errors, a persistent 506 prevents indexing. It is a configuration error, so fix the negotiation setup (type maps, MultiViews) instead of waiting for it to go away.
Common causes and use cases
- An Apache type map (
.varfile) lists a variant that is itself a type map. - MultiViews combined with type maps leads to circular negotiation.
- An experimental content negotiation setup has a misconfigured list of variants.