Package http provides HTTP client and server implementations.

[Get], [Head], [Post], and [PostForm] make HTTP (or HTTPS) requests:

 resp, err := http.Get("http://example.com/")
 ...
 resp, err := http.Post("http://example.com/upload", "image/jpeg", &buf)
 ...
 resp, err := http.PostForm("http://example.com/form",
   url.Values{"key": {"Value"}, "id": {"123"}})
Copy

The caller must close the response body when finished with it:

 resp, err := http.Get("http://example.com/")
 if err != nil {
   // handle error
 }
 defer resp.Body.Close()
 body, err := io.ReadAll(resp.Body)
 // ...
Copy

Clients and Transports

For control over HTTP client headers, redirect policy, and other settings, create a [Client]:

 client := &http.Client{
   CheckRedirect: redirectPolicyFunc,
 }

 resp, err := client.Get("http://example.com")
 // ...

 req, err := http.NewRequest("GET", "http://example.com", nil)
 // ...
 req.Header.Add("If-None-Match", `W/"wyzzy"`)
 resp, err := client.Do(req)
 // ...
Copy

For control over proxies, TLS configuration, keep-alives, compression, and other settings, create a [Transport]:

 tr := &http.Transport{
   MaxIdleConns:       10,
   IdleConnTimeout:    30 * time.Second,
   DisableCompression: true,
 }
 client := &http.Client{Transport: tr}
 resp, err := client.Get("https://example.com")
Copy

Clients and Transports are safe for concurrent use by multiple goroutines and for efficiency should only be created once and re-used.

Servers

ListenAndServe starts an HTTP server with a given address and handler. The handler is usually nil, which means to use [DefaultServeMux]. [Handle] and [HandleFunc] add handlers to [DefaultServeMux]:

 http.Handle("/foo", fooHandler)

 http.HandleFunc("/bar", func(w http.ResponseWriter, r *http.Request) {
   fmt.Fprintf(w, "Hello, %q", html.EscapeString(r.URL.Path))
 })

 log.Fatal(http.ListenAndServe(":8080", nil))
Copy

More control over the server's behavior is available by creating a custom Server:

 s := &http.Server{
   Addr:           ":8080",
   Handler:        myHandler,
   ReadTimeout:    10 * time.Second,
   WriteTimeout:   10 * time.Second,
   MaxHeaderBytes: 1 << 20,
 }
 log.Fatal(s.ListenAndServe())
Copy

HTTP/2

Starting with Go 1.6, the http package has transparent support for the HTTP/2 protocol when using HTTPS. Programs that must disable HTTP/2 can do so by setting [Transport.TLSNextProto] (for clients) or [Server.TLSNextProto] (for servers) to a non-nil, empty map. Alternatively, the following GODEBUG settings are currently supported:

 GODEBUG=http2client=0  # disable HTTP/2 client support
 GODEBUG=http2server=0  # disable HTTP/2 server support
 GODEBUG=http2debug=1   # enable verbose HTTP/2 debug logs
 GODEBUG=http2debug=2   # ... even more verbose, with frame dumps
Copy

Please report any issues before disabling HTTP/2 support: https://golang.org/s/http2bug

The http package's [Transport] and [Server] both automatically enable HTTP/2 support for simple configurations. To enable HTTP/2 for more complex configurations, to use lower-level HTTP/2 features, or to use a newer version of Go's http2 package, import "golang.org/x/net/http2" directly and use its ConfigureTransport and/or ConfigureServer functions. Manually configuring HTTP/2 via the golang.org/x/net/http2 package takes precedence over the net/http package's built-in HTTP/2 support.