diff --git a/src/assert.cc b/src/assert.cc
index e93319a4..018567da 100644
--- a/src/assert.cc
+++ b/src/assert.cc
@@ -15,8 +15,8 @@ namespace Kakoune
 
 struct assert_failed : logic_error
 {
-    assert_failed(const String& message)
-        : m_message(message) {}
+    assert_failed(String message)
+        : m_message(std::move(message)) {}
 
     const char* what() const override { return m_message.c_str(); }
 private:
diff --git a/src/buffer.cc b/src/buffer.cc
index 2f80cc9c..4e5b1f8e 100644
--- a/src/buffer.cc
+++ b/src/buffer.cc
@@ -507,7 +507,7 @@ void Buffer::on_option_changed(const Option& option)
                             option.name() + "=" + option.get_as_string());
 }
 
-void Buffer::run_hook_in_own_context(const String& hook_name, const String& param)
+void Buffer::run_hook_in_own_context(const String& hook_name, StringView param)
 {
     InputHandler hook_handler({ *this, Selection{} });
     m_hooks.run_hook(hook_name, param, hook_handler.context());
diff --git a/src/buffer.hh b/src/buffer.hh
index 303123d3..4f0da060 100644
--- a/src/buffer.hh
+++ b/src/buffer.hh
@@ -157,7 +157,7 @@ public:
 
     ValueMap& values() const { return m_values; }
 
-    void run_hook_in_own_context(const String& hook_name, const String& param);
+    void run_hook_in_own_context(const String& hook_name, StringView param);
 
     void reload(std::vector<String> lines, time_t fs_timestamp = InvalidTime);
 
diff --git a/src/buffer_utils.cc b/src/buffer_utils.cc
index 1d7e7d25..c3dd755c 100644
--- a/src/buffer_utils.cc
+++ b/src/buffer_utils.cc
@@ -133,7 +133,7 @@ Buffer* create_fifo_buffer(String name, int fd, bool scroll)
     });
 
     buffer->hooks().add_hook("BufClose", "",
-        [buffer, watcher](const String&, const Context&) {
+        [buffer, watcher](StringView, const Context&) {
             // Check if fifo is still alive, else watcher is already dead
             if (buffer->flags() & Buffer::Flags::Fifo)
             {
diff --git a/src/client_manager.cc b/src/client_manager.cc
index bc833c62..87abcf3e 100644
--- a/src/client_manager.cc
+++ b/src/client_manager.cc
@@ -26,7 +26,7 @@ String ClientManager::generate_name() const
 
 Client* ClientManager::create_client(std::unique_ptr<UserInterface>&& ui,
                                      EnvVarMap env_vars,
-                                     const String& init_commands)
+                                     StringView init_commands)
 {
     Buffer& buffer = **BufferManager::instance().begin();
     WindowAndSelections ws = get_free_window(buffer);
@@ -139,14 +139,14 @@ void ClientManager::ensure_no_client_uses_buffer(Buffer& buffer)
     m_free_windows.erase(end, m_free_windows.end());
 }
 
-bool ClientManager::validate_client_name(const String& name) const
+bool ClientManager::validate_client_name(StringView name) const
 {
     auto it = find_if(m_clients, [&](const std::unique_ptr<Client>& client)
                                  { return client->context().name() == name; });
     return it == m_clients.end();
 }
 
-Client* ClientManager::get_client_ifp(const String& name)
+Client* ClientManager::get_client_ifp(StringView name)
 {
     for (auto& client : m_clients)
     {
@@ -156,7 +156,7 @@ Client* ClientManager::get_client_ifp(const String& name)
     return nullptr;
 }
 
-Client& ClientManager::get_client(const String& name)
+Client& ClientManager::get_client(StringView name)
 {
     Client* client = get_client_ifp(name);
     if (not client)
diff --git a/src/client_manager.hh b/src/client_manager.hh
index e4d6da43..2c2e01bc 100644
--- a/src/client_manager.hh
+++ b/src/client_manager.hh
@@ -23,7 +23,7 @@ public:
     ~ClientManager();
 
     Client* create_client(std::unique_ptr<UserInterface>&& ui,
-                          EnvVarMap env_vars, const String& init_cmd);
+                          EnvVarMap env_vars, StringView init_cmd);
 
     bool   empty() const { return m_clients.empty(); }
     size_t count() const { return m_clients.size(); }
@@ -36,9 +36,9 @@ public:
     void redraw_clients() const;
     void clear_mode_trashes() const;
 
-    Client*  get_client_ifp(const String& name);
-    Client&  get_client(const String& name);
-    bool validate_client_name(const String& name) const;
+    Client*  get_client_ifp(StringView name);
+    Client&  get_client(StringView name);
+    bool validate_client_name(StringView name) const;
     void remove_client(Client& client);
 
     CandidateList complete_client_name(StringView name,
diff --git a/src/commands.cc b/src/commands.cc
index cdab704f..1770df1e 100644
--- a/src/commands.cc
+++ b/src/commands.cc
@@ -546,13 +546,13 @@ const CommandDesc add_hook_cmd = {
         // copy so that the lambda gets a copy as well
         Regex regex(parser[2].begin(), parser[2].end());
         String command = parser[3];
-        auto hook_func = [=](const String& param, Context& context) {
+        auto hook_func = [=](StringView param, Context& context) {
             if (context.are_user_hooks_disabled())
                 return;
 
             if (regex_match(param.begin(), param.end(), regex))
                 CommandManager::instance().execute(command, context, {},
-                                                   { { "hook_param", param } });
+                                                   { { "hook_param", param.str() } });
         };
         StringView group;
         if (parser.has_option("group"))
diff --git a/src/function_registry.hh b/src/function_registry.hh
index b7296eac..5f3732ba 100644
--- a/src/function_registry.hh
+++ b/src/function_registry.hh
@@ -11,7 +11,7 @@ namespace Kakoune
 
 struct function_not_found : runtime_error
 {
-    function_not_found(const String& name)
+    function_not_found(StringView name)
         : runtime_error("'" + name + "' not found") {}
 };
 
diff --git a/src/hook_manager.cc b/src/hook_manager.cc
index cfade4d7..70e1c8eb 100644
--- a/src/hook_manager.cc
+++ b/src/hook_manager.cc
@@ -37,8 +37,7 @@ CandidateList HookManager::complete_hook_group(StringView prefix, ByteCount pos_
 }
 
 void HookManager::run_hook(const String& hook_name,
-                           const String& param,
-                           Context& context) const
+                           StringView param, Context& context) const
 {
     if (m_parent)
         m_parent->run_hook(hook_name, param, context);
diff --git a/src/hook_manager.hh b/src/hook_manager.hh
index e5c94850..dd1c6eeb 100644
--- a/src/hook_manager.hh
+++ b/src/hook_manager.hh
@@ -10,7 +10,7 @@ namespace Kakoune
 {
 
 class Context;
-using HookFunc = std::function<void (const String&, Context&)>;
+using HookFunc = std::function<void (StringView, Context&)>;
 
 class HookManager
 {
@@ -20,7 +20,7 @@ public:
     void add_hook(const String& hook_name, String group, HookFunc hook);
     void remove_hooks(StringView group);
     CandidateList complete_hook_group(StringView prefix, ByteCount pos_in_token);
-    void run_hook(const String& hook_name, const String& param,
+    void run_hook(const String& hook_name, StringView param,
                   Context& context) const;
 
 private:
diff --git a/src/input_handler.cc b/src/input_handler.cc
index e4368e7f..badac088 100644
--- a/src/input_handler.cc
+++ b/src/input_handler.cc
@@ -274,12 +274,12 @@ public:
         }
     }
 
-    void insert(const String& str)
+    void insert(StringView str)
     {
         insert_from(m_cursor_pos, str);
     }
 
-    void insert_from(CharCount start, const String& str)
+    void insert_from(CharCount start, StringView str)
     {
         kak_assert(start <= m_cursor_pos);
         m_line = m_line.substr(0, start) + str
@@ -459,7 +459,7 @@ String common_prefix(memoryview<String> strings)
     return res;
 }
 
-void history_push(std::vector<String>& history, const String& entry)
+void history_push(std::vector<String>& history, StringView entry)
 {
     if(entry.empty())
     {
diff --git a/src/normal.cc b/src/normal.cc
index 49eae94d..67640b7d 100644
--- a/src/normal.cc
+++ b/src/normal.cc
@@ -107,7 +107,7 @@ void repeat_last_insert(Context& context, int)
     context.input_handler().repeat_last_insert();
 }
 
-bool show_auto_info_ifn(const String& title, const String& info,
+bool show_auto_info_ifn(StringView title, StringView info,
                         const Context& context)
 {
     if (context.options()["autoinfo"].get<int>() < 1 or not context.has_ui())
@@ -121,7 +121,7 @@ bool show_auto_info_ifn(const String& title, const String& info,
 
 template<typename Cmd>
 void on_next_key_with_autoinfo(const Context& context, KeymapMode keymap_mode, Cmd cmd,
-                               const String& title, const String& info)
+                               StringView title, StringView info)
 {
     const bool hide = show_auto_info_ifn(title, info, context);
     context.input_handler().on_next_key(
diff --git a/src/parameters_parser.hh b/src/parameters_parser.hh
index 5b177bb3..219c9454 100644
--- a/src/parameters_parser.hh
+++ b/src/parameters_parser.hh
@@ -18,13 +18,13 @@ struct parameter_error : public runtime_error
 
 struct unknown_option : public parameter_error
 {
-    unknown_option(const String& name)
+    unknown_option(StringView name)
         : parameter_error("unknown option '" + name + "'") {}
 };
 
 struct missing_option_value: public parameter_error
 {
-    missing_option_value(const String& name)
+    missing_option_value(StringView name)
         : parameter_error("missing value for option '" + name + "'") {}
 };
 
diff --git a/src/remote.cc b/src/remote.cc
index 12bdf580..58dd7233 100644
--- a/src/remote.cc
+++ b/src/remote.cc
@@ -409,12 +409,13 @@ void RemoteUI::set_input_callback(InputCallback callback)
 
 RemoteClient::RemoteClient(int socket, std::unique_ptr<UserInterface>&& ui,
                            const EnvVarMap& env_vars,
-                           const String& init_command)
+                           StringView init_command)
     : m_ui(std::move(ui)), m_dimensions(m_ui->dimensions()),
       m_socket_watcher{socket, [this](FDWatcher&){ process_available_messages(); }}
 {
     Message msg(socket);
-    msg.write(init_command.c_str(), (int)init_command.length()+1);
+    msg.write(init_command.data(), (int)init_command.length());
+    msg.write((char)0);
     msg.write(env_vars);
 
     Key key{ resize_modifier, Codepoint(((int)m_dimensions.line << 16) |
@@ -504,10 +505,10 @@ void RemoteClient::write_next_key()
     }
 }
 
-std::unique_ptr<RemoteClient> connect_to(const String& session,
+std::unique_ptr<RemoteClient> connect_to(StringView session,
                                          std::unique_ptr<UserInterface>&& ui,
                                          const EnvVarMap& env_vars,
-                                         const String& init_command)
+                                         StringView init_command)
 {
     auto filename = "/tmp/kak-" + session;
 
@@ -524,7 +525,7 @@ std::unique_ptr<RemoteClient> connect_to(const String& session,
                                                           init_command}};
 }
 
-void send_command(const String& session, const String& command)
+void send_command(StringView session, StringView command)
 {
     auto filename = "/tmp/kak-" + session;
 
@@ -538,7 +539,7 @@ void send_command(const String& session, const String& command)
 
     {
         Message msg(sock);
-        msg.write(command.c_str(), (int)command.length());
+        msg.write(command.data(), (int)command.length());
     }
     close(sock);
 }
diff --git a/src/remote.hh b/src/remote.hh
index aa2af7b1..2d56011c 100644
--- a/src/remote.hh
+++ b/src/remote.hh
@@ -13,7 +13,7 @@ struct peer_disconnected {};
 
 struct connection_failed : runtime_error
 {
-    connection_failed(const String& filename)
+    connection_failed(StringView filename)
         : runtime_error{"connect to " + filename + " failed"}
     {}
 };
@@ -24,7 +24,7 @@ class RemoteClient
 {
 public:
     RemoteClient(int socket, std::unique_ptr<UserInterface>&& ui,
-                 const EnvVarMap& env_vars, const String& init_command);
+                 const EnvVarMap& env_vars, StringView init_command);
 
 private:
     void process_available_messages();
@@ -35,12 +35,12 @@ private:
     CharCoord                      m_dimensions;
     FDWatcher                      m_socket_watcher;
 };
-std::unique_ptr<RemoteClient> connect_to(const String& session,
+std::unique_ptr<RemoteClient> connect_to(StringView session,
                                          std::unique_ptr<UserInterface>&& ui,
                                          const EnvVarMap& env_vars,
-                                         const String& init_command);
+                                         StringView init_command);
 
-void send_command(const String& session, const String& command);
+void send_command(StringView session, StringView command);
 
 struct Server : public Singleton<Server>
 {