HTTP 505 Http Version Not Supported Error - Meaning & Fix

The 505 HTTP Version Not Supported status code means the server cannot handle the HTTP version used in your request. This occurs because the server supports different HTTP versions than the one sent. In web scraping, this can happen when a scraper sends requests using an outdated HTTP version or one that the target website does not recognize. Some websites enforce strict HTTP version policies as an anti-scraping measure.

Main causes

Client uses an outdated HTTP version that the server no longer supports – scrapers using old libraries or default settings may send HTTP/1.0 requests when the server only supports HTTP/1.1 or HTTP/2.
Server is configured to only accept requests from specific HTTP versions for security or compatibility reasons.
Misconfiguration in server settings that restricts it from accepting the HTTP version used in the request.
Network devices (like proxies or firewalls) between the client and server that block certain HTTP versions.

# Request example 
curl -X POST https://sandbox.oxylabs.io/ -H 'Accept: application/xml;q=0.9' -H 'Accept-Encoding: br' -H 'User-Agent: AppleWebKit/537.36'

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Common fixes

Check the HTTP version used in your request and compare it with the versions supported by the server.
Update your web scraping libraries.
Update your client or server software to ensure compatibility with the HTTP version used.
Modify the HTTP version in your request headers to match one that the server supports.
Contact the server administrator to confirm the supported HTTP versions and request an update if necessary.

# Response example HTTP/1.1 505 HTTP Version Not Supported Content-Type: text/html 505 HTTP Version Not Supported

HTTP Version Not Supported

The server does not support the HTTP protocol version used in the request.

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Common scraping HTTP error codes

401 Unauthorized	403 Forbidden	404 Not found	405 Method not allowed	406 Not acceptable
407 Proxy authentication required	408 Request timeout	409 Conflict	410 Gone	411 Length required
412 Precondition failed	413 Payload too large	414 Uri too long	415 Unsupported media type	416 Range not satisfiable
417 Expectation failed	421 Misdirected request	422 Unprocessable entity	423 Locked	424 Failed dependency
426 Upgrade required	428 Precondition required	429 Too many requests	431 Request header fields too large	444 Connection: close
451 Unavailable for legal reasons	499 Client closed request	501 Not implemented	503 Service unavailable	505 Http version not supported
506 Variant also negotiates	507 Insufficient storage	508 Loop detected	510 Not extended	511 Network authentication required