diff --git a/core/io/http_client.cpp b/core/io/http_client.cpp
index 4d72f744e15..9e301ccac59 100644
--- a/core/io/http_client.cpp
+++ b/core/io/http_client.cpp
@@ -618,7 +618,27 @@ String HTTPClient::query_string_from_dict(const Dictionary &p_dict) {
 	String query = "";
 	Array keys = p_dict.keys();
 	for (int i = 0; i < keys.size(); ++i) {
-		query += "&" + String(keys[i]).http_escape() + "=" + String(p_dict[keys[i]]).http_escape();
+		String encoded_key = String(keys[i]).http_escape();
+		Variant value = p_dict[keys[i]];
+		switch (value.get_type()) {
+			case Variant::ARRAY: {
+				// Repeat the key with every values
+				Array values = value;
+				for (int j = 0; j < values.size(); ++j) {
+					query += "&" + encoded_key + "=" + String(values[j]).http_escape();
+				}
+				break;
+			}
+			case Variant::NIL: {
+				// Add the key with no value
+				query += "&" + encoded_key;
+				break;
+			}
+			default: {
+				// Add the key-value pair
+				query += "&" + encoded_key + "=" + String(value).http_escape();
+			}
+		}
 	}
 	query.erase(0, 1);
 	return query;
diff --git a/core/ustring.cpp b/core/ustring.cpp
index a7a78108379..954f5902184 100644
--- a/core/ustring.cpp
+++ b/core/ustring.cpp
@@ -3168,8 +3168,8 @@ String String::word_wrap(int p_chars_per_line) const {
 String String::http_escape() const {
 	const CharString temp = utf8();
 	String res;
-	for (int i = 0; i < length(); ++i) {
-		CharType ord = temp[i];
+	for (int i = 0; i < temp.length(); ++i) {
+		char ord = temp[i];
 		if (ord == '.' || ord == '-' || ord == '_' || ord == '~' ||
 				(ord >= 'a' && ord <= 'z') ||
 				(ord >= 'A' && ord <= 'Z') ||
@@ -3178,9 +3178,9 @@ String String::http_escape() const {
 		} else {
 			char h_Val[3];
 #if defined(__GNUC__) || defined(_MSC_VER)
-			snprintf(h_Val, 3, "%.2X", ord);
+			snprintf(h_Val, 3, "%hhX", ord);
 #else
-			sprintf(h_Val, "%.2X", ord);
+			sprintf(h_Val, "%hhX", ord);
 #endif
 			res += "%";
 			res += h_Val;
diff --git a/doc/classes/HTTPClient.xml b/doc/classes/HTTPClient.xml
index 5627f585e4f..3f0668ba0f8 100644
--- a/doc/classes/HTTPClient.xml
+++ b/doc/classes/HTTPClient.xml
@@ -111,6 +111,12 @@
 				String queryString = httpClient.query_string_from_dict(fields)
 				returns:= "username=user&amp;password=pass"
 				[/codeblock]
+				Furthermore, if a key has a null value, only the key itself is added, without equal sign and value. If the value is an array, for each value in it a pair with the same key is added.
+				[codeblock]
+				var fields = {"single": 123, "not_valued": null, "multiple": [22, 33, 44]}
+				String queryString = httpClient.query_string_from_dict(fields)
+				returns:= "single=123&amp;not_valued&amp;multiple=22&amp;multiple=33&amp;multiple=44"
+				[/codeblock]
 			</description>
 		</method>
 		<method name="read_response_body_chunk">