Web Protocols

HTTP/1.0

The first widely documented version of HTTP, which introduced headers, status codes and content types — but opened and closed a fresh TCP connection for every single request.

What it is

HTTP/1.0 (RFC 1945, 1996) turned the one-line HTTP/0.9 protocol into a real application protocol: request methods, three-digit status codes, request and response headers, and Content-Type for arbitrary media. Its defining limitation is one request per TCP connection — every asset needed a new connection and a new handshake.

HTTP/1.0 REQUEST
GET /index.html HTTP/1.0
Host: example.com
User-Agent: Mozilla/5.0

Why it matters

  • It established the header/status/method model every later HTTP version still uses.
  • Its connection-per-request cost is the problem HTTP/1.1 keep-alive and HTTP/2 multiplexing were built to solve.

Common mistakes

  • Assuming HTTP/1.0 supports persistent connections by default — it does not without the non-standard Connection: keep-alive.
  • Relying on the Host header being mandatory; it only became required in HTTP/1.1, enabling virtual hosting.

How WebInspect checks this

  • WebInspect reports the negotiated HTTP version so you can confirm a server is not falling back to HTTP/1.0.