diff --git a/context.go b/context.go
index 85a0a9a..8a9b53f 100644
--- a/context.go
+++ b/context.go
@@ -53,7 +53,7 @@ func (ctx *context) Next() error {
 // Redirects the client to a different location with the specified status code.
 func (ctx *context) Redirect(status int, location string) error {
 	ctx.response.SetStatus(status)
-	ctx.response.SetHeader("Location", location)
+	ctx.response.SetHeader(HeaderLocation, location)
 	return nil
 }
 
diff --git a/header.go b/header.go
index ae86680..4d73350 100644
--- a/header.go
+++ b/header.go
@@ -1,6 +1,63 @@
 package web
 
+// Header represents an HTTP header with key and value
 type Header struct {
 	Key   string
 	Value string
 }
+
+// Common HTTP header keys
+const (
+	HeaderContentType      = "Content-Type"
+	HeaderContentLength    = "Content-Length"
+	HeaderHost             = "Host"
+	HeaderAccept           = "Accept"
+	HeaderUserAgent        = "User-Agent"
+	HeaderAcceptEncoding   = "Accept-Encoding"
+	HeaderAcceptLanguage   = "Accept-Language"
+	HeaderConnection       = "Connection"
+	HeaderCookie           = "Cookie"
+	HeaderSetCookie        = "Set-Cookie"
+	HeaderLocation         = "Location"
+	HeaderAuthorization    = "Authorization"
+	HeaderCacheControl     = "Cache-Control"
+	HeaderOrigin           = "Origin"
+	HeaderReferer          = "Referer"
+	HeaderTransferEncoding = "Transfer-Encoding"
+)
+
+// Pre-allocated common headers
+var (
+	// Content type headers
+	HeaderContentTypeJSON      = Header{Key: HeaderContentType, Value: "application/json"}
+	HeaderContentTypeHTML      = Header{Key: HeaderContentType, Value: "text/html"}
+	HeaderContentTypePlain     = Header{Key: HeaderContentType, Value: "text/plain"}
+	HeaderContentTypeXML       = Header{Key: HeaderContentType, Value: "application/xml"}
+	HeaderContentTypeForm      = Header{Key: HeaderContentType, Value: "application/x-www-form-urlencoded"}
+	HeaderContentTypeMultipart = Header{Key: HeaderContentType, Value: "multipart/form-data"}
+
+	// Connection headers
+	HeaderConnectionClose     = Header{Key: HeaderConnection, Value: "close"}
+	HeaderConnectionKeepAlive = Header{Key: HeaderConnection, Value: "keep-alive"}
+)
+
+// FindHeader looks for a header by key in a slice of headers
+func FindHeader(headers []Header, key string) (string, bool) {
+	for _, h := range headers {
+		if h.Key == key {
+			return h.Value, true
+		}
+	}
+	return "", false
+}
+
+// SetHeader sets a header value in a slice of headers
+func SetHeader(headers *[]Header, key string, value string) {
+	for i, h := range *headers {
+		if h.Key == key {
+			(*headers)[i].Value = value
+			return
+		}
+	}
+	*headers = append(*headers, Header{Key: key, Value: value})
+}
diff --git a/request.go b/request.go
index a57272f..b0dcccb 100644
--- a/request.go
+++ b/request.go
@@ -32,13 +32,8 @@ type request struct {
 
 // Returns the header value for the given key.
 func (req *request) Header(key string) string {
-	for _, header := range req.headers {
-		if header.Key == key {
-			return header.Value
-		}
-	}
-
-	return ""
+	value, _ := FindHeader(req.headers, key)
+	return value
 }
 
 // Returns the requested host.
diff --git a/response.go b/response.go
index c1ae09d..d15c1f0 100644
--- a/response.go
+++ b/response.go
@@ -28,25 +28,13 @@ func (res *response) Body() []byte {
 
 // Returns the header value for the given key.
 func (res *response) Header(key string) string {
-	for _, header := range res.headers {
-		if header.Key == key {
-			return header.Value
-		}
-	}
-
-	return ""
+	value, _ := FindHeader(res.headers, key)
+	return value
 }
 
 // Sets the header value for the given key.
 func (res *response) SetHeader(key string, value string) {
-	for i, header := range res.headers {
-		if header.Key == key {
-			res.headers[i].Value = value
-			return
-		}
-	}
-
-	res.headers = append(res.headers, Header{Key: key, Value: value})
+	SetHeader(&res.headers, key, value)
 }
 
 // Replaces the response body with the new contents.
diff --git a/server.go b/server.go
index 1025c6a..fafe28e 100644
--- a/server.go
+++ b/server.go
@@ -210,7 +210,7 @@ func (s *server) handleConnection(conn net.Conn) {
 		}
 
 		// Read the body, if any
-		if contentLength := ctx.request.Header("Content-Length"); contentLength != "" {
+		if contentLength := ctx.request.Header(HeaderContentLength); contentLength != "" {
 			length, _ := strconv.Atoi(contentLength)
 			ctx.request.body = make([]byte, length)
 			ctx.reader.Read(ctx.request.body)
@@ -244,7 +244,7 @@ func (s *server) handleRequest(ctx *context, method string, url string, writer i
 	tmp := bytes.Buffer{}
 	tmp.WriteString("HTTP/1.1 ")
 	tmp.WriteString(strconv.Itoa(int(ctx.status)))
-	tmp.WriteString("\r\nContent-Length: ")
+	tmp.WriteString("\r\n" + HeaderContentLength + ": ")
 	tmp.WriteString(strconv.Itoa(len(ctx.response.body)))
 	tmp.WriteString("\r\n")