diff --git a/plinth/modules/dynamicdns/static/dynamicdns.js b/plinth/modules/dynamicdns/static/dynamicdns.js
index 7ee0bcbb0..73d3435d4 100644
--- a/plinth/modules/dynamicdns/static/dynamicdns.js
+++ b/plinth/modules/dynamicdns/static/dynamicdns.js
@@ -22,58 +22,60 @@
  * in this page.
  */
 
-(function($) {
-    var NOIP = 'https://<User>:<Pass>@dynupdate.no-ip.com/nic/update?' +
+document.addEventListener('DOMContentLoaded', () => {
+    const NOIP = 'https://<User>:<Pass>@dynupdate.no-ip.com/nic/update?' +
         'hostname=<Domain>';
-    var FREEDNS = 'https://freedns.afraid.org/dynamic/update.php?' +
+    const FREEDNS = 'https://freedns.afraid.org/dynamic/update.php?' +
         '_YOURAPIKEYHERE_';
 
-    $('#id_service_type').change(function() {
-        set_mode();
+    document.getElementById('id_service_type').addEventListener('change', () => {
+        setMode();
 
-        var service_type = $("#id_service_type").val();
-        if (service_type == "noip.com") {
-            $('#id_update_url').val(NOIP);
-        } else if (service_type == "freedns.afraid.org") {
-            $('#id_update_url').val(FREEDNS);
+        const service_type = document.getElementById('id_service_type').value;
+        if (service_type === "noip.com") {
+            document.getElementById('id_update_url').value = NOIP;
+        } else if (service_type === "freedns.afraid.org") {
+            document.getElementById('id_update_url').value = FREEDNS;
         } else {  // GnuDIP and other
-            $('#id_update_url').val('');
+            document.getElementById('id_update_url').value = '';
         }
     });
 
-    $('#id_show_password').change(function() {
-        if ($('#id_show_password').prop('checked')) {
-            $('#id_password').prop('type', 'text');
+    document.getElementById('id_show_password').addEventListener('change', () => {
+        if (document.getElementById('id_show_password').checked) {
+            document.getElementById('id_password').type = 'text';
         } else {
-            $('#id_password').prop('type', 'password');
+            document.getElementById('id_password').type = 'password';
         }
     });
 
-    function set_mode() {
-        var service_type = $("#id_service_type").val();
-        if (service_type == "gnudip") {
-            set_gnudip_mode();
+    function setMode() {
+        const service_type = document.getElementById('id_service_type').value;
+        if (service_type === "gnudip") {
+            setGnudipMode();
         } else {
-            set_update_url_mode();
+            setUpdateUrlMode();
         }
     }
 
-    function set_gnudip_mode() {
-        $('.form-group').show();
-        $('#id_update_url').closest('.form-group').hide();
-        $('#id_disable_ssl_cert_check').closest('.form-group').hide();
-        $('#id_use_http_basic_auth').closest('.form-group').hide();
-        $('#id_use_ipv6').closest('.form-group').hide();
-        $('#id_server').closest('.form-group').show();
+    function setGnudipMode() {
+        document.querySelectorAll('.form-group').forEach((element) => {
+            element.style.display = 'block';
+        });
+        document.getElementById('id_update_url').closest('.form-group').style.display = 'none';
+        document.getElementById('id_disable_ssl_cert_check').closest('.form-group').style.display = 'none';
+        document.getElementById('id_use_http_basic_auth').closest('.form-group').style.display = 'none';
+        document.getElementById('id_use_ipv6').closest('.form-group').style.display = 'none';
+        document.getElementById('id_server').closest('.form-group').style.display = 'block';
     }
 
-    function set_update_url_mode() {
-        $('#id_update_url').closest('.form-group').show();
-        $('#id_disable_ssl_cert_check').closest('.form-group').show();
-        $('#id_use_http_basic_auth').closest('.form-group').show();
-        $('#id_use_ipv6').closest('.form-group').show();
-        $('#id_server').closest('.form-group').hide();
+    function setUpdateUrlMode() {
+        document.getElementById('id_update_url').closest('.form-group').style.display = 'block';
+        document.getElementById('id_disable_ssl_cert_check').closest('.form-group').style.display = 'block';
+        document.getElementById('id_use_http_basic_auth').closest('.form-group').style.display = 'block';
+        document.getElementById('id_use_ipv6').closest('.form-group').style.display = 'block';
+        document.getElementById('id_server').closest('.form-group').style.display = 'none';
     }
 
-    set_mode();
-})(jQuery);
+    setMode();
+});
diff --git a/plinth/modules/ejabberd/static/ejabberd.js b/plinth/modules/ejabberd/static/ejabberd.js
index 6822a474e..7e16492cd 100644
--- a/plinth/modules/ejabberd/static/ejabberd.js
+++ b/plinth/modules/ejabberd/static/ejabberd.js
@@ -22,14 +22,21 @@
  * in this page.
  */
 
-jQuery(function($) {
-    $('#id_enable_managed_turn').change(function() {
-        if($(this).prop('checked')) {
-            $('#id_turn_uris').closest('.form-group').hide();
-            $('#id_shared_secret').closest('.form-group').hide();
+document.addEventListener('DOMContentLoaded', () => {
+    const enableManagedTurn = document.getElementById('id_enable_managed_turn');
+    const turnUrisGroup = document.getElementById('id_turn_uris').closest('.form-group');
+    const sharedSecretGroup = document.getElementById('id_shared_secret').closest('.form-group');
+
+    function toggleVisibility() {
+        if (enableManagedTurn.checked) {
+            turnUrisGroup.style.display = 'none';
+            sharedSecretGroup.style.display = 'none';
         } else {
-            $('#id_turn_uris').closest('.form-group').show();
-            $('#id_shared_secret').closest('.form-group').show();
+            turnUrisGroup.style.display = '';
+            sharedSecretGroup.style.display = '';
         }
-    }).change();
+    }
+
+    enableManagedTurn.addEventListener('change', toggleVisibility);
+    toggleVisibility();
 });
diff --git a/plinth/modules/janus/__init__.py b/plinth/modules/janus/__init__.py
index f1e6ae8e1..9d2cceaa4 100644
--- a/plinth/modules/janus/__init__.py
+++ b/plinth/modules/janus/__init__.py
@@ -59,9 +59,9 @@ class JanusApp(app_module.App):
         self.add(shortcut)
 
         packages = Packages('packages-janus', [
-            'janus', 'libjs-bootbox', 'libjs-bootstrap', 'libjs-bootswatch',
-            'libjs-janus-gateway', 'libjs-jquery-blockui', 'libjs-spin.js',
-            'libjs-toastr', 'libjs-webrtc-adapter'
+            'janus', 'libjs-jquery', 'libjs-bootbox', 'libjs-bootstrap',
+            'libjs-bootswatch', 'libjs-janus-gateway', 'libjs-jquery-blockui',
+            'libjs-spin.js', 'libjs-toastr', 'libjs-webrtc-adapter'
         ])
         self.add(packages)
 
diff --git a/plinth/modules/matrixsynapse/static/matrixsynapse.js b/plinth/modules/matrixsynapse/static/matrixsynapse.js
index 6822a474e..0d0f7eabe 100644
--- a/plinth/modules/matrixsynapse/static/matrixsynapse.js
+++ b/plinth/modules/matrixsynapse/static/matrixsynapse.js
@@ -22,14 +22,21 @@
  * in this page.
  */
 
-jQuery(function($) {
-    $('#id_enable_managed_turn').change(function() {
-        if($(this).prop('checked')) {
-            $('#id_turn_uris').closest('.form-group').hide();
-            $('#id_shared_secret').closest('.form-group').hide();
+document.addEventListener('DOMContentLoaded', () => {
+    const enableManagedTurnCheckbox = document.getElementById('id_enable_managed_turn');
+    const turnUrisFormGroup = document.getElementById('id_turn_uris').closest('.form-group');
+    const sharedSecretFormGroup = document.getElementById('id_shared_secret').closest('.form-group');
+
+    function toggleFormGroups() {
+        if (enableManagedTurnCheckbox.checked) {
+            turnUrisFormGroup.style.display = 'none';
+            sharedSecretFormGroup.style.display = 'none';
         } else {
-            $('#id_turn_uris').closest('.form-group').show();
-            $('#id_shared_secret').closest('.form-group').show();
+            turnUrisFormGroup.style.display = '';
+            sharedSecretFormGroup.style.display = '';
         }
-    }).change();
+    }
+
+    enableManagedTurnCheckbox.addEventListener('change', toggleFormGroups);
+    toggleFormGroups();
 });
diff --git a/plinth/modules/mediawiki/static/mediawiki.js b/plinth/modules/mediawiki/static/mediawiki.js
index be0303b6d..8d868cca5 100644
--- a/plinth/modules/mediawiki/static/mediawiki.js
+++ b/plinth/modules/mediawiki/static/mediawiki.js
@@ -22,18 +22,19 @@
  * in this page.
  */
 
-(function($) {
-    $('#id_enable_public_registrations').click(function() {
-        var checkedState = $(this).prop("checked");
-        if (checkedState) {
-            $('#id_enable_private_mode').prop('checked', false);
+document.addEventListener('DOMContentLoaded', () => {
+    const enablePublicRegistrations = document.getElementById('id_enable_public_registrations');
+    const enablePrivateMode = document.getElementById('id_enable_private_mode');
+
+    enablePublicRegistrations.addEventListener('click', () => {
+        if (enablePublicRegistrations.checked) {
+            enablePrivateMode.checked = false;
         }
     });
 
-    $('#id_enable_private_mode').click(function() {
-        var checkedState = $(this).prop("checked");
-        if (checkedState) {
-            $('#id_enable_public_registrations').prop('checked', false);
+    enablePrivateMode.addEventListener('click', () => {
+        if (enablePrivateMode.checked) {
+            enablePublicRegistrations.checked = false;
         }
     });
-})(jQuery);
+});
diff --git a/plinth/modules/networks/static/networks.js b/plinth/modules/networks/static/networks.js
index af2260051..6b0ec2b96 100644
--- a/plinth/modules/networks/static/networks.js
+++ b/plinth/modules/networks/static/networks.js
@@ -22,81 +22,94 @@
  * in this page.
  */
 
-jQuery(function($) {
+document.addEventListener('DOMContentLoaded', () => {
 
-    function ip_required(required, ip_version, fields) {
-        var prefix = '#id_' + ip_version + '_';
+    function ipRequired(required, ipVersion, fields) {
+        const prefix = 'id_' + ipVersion + '_';
         for (var i = 0; i < fields.length; i++) {
-            $(prefix + fields[i]).prop("required", required);
-        }
-    }
-
-    function ip_readonly(readonly, ip_version, fields) {
-        var prefix = '#id_' + ip_version + '_';
-        for (var i = 0; i < fields.length; i++) {
-            $(prefix + fields[i]).prop("readOnly", readonly);
-            if (readonly) {
-                $(prefix + fields[i]).val("");
-                $(prefix + fields[i]).prop("required", false);
+            const element = document.getElementById(prefix + fields[i]);
+            if (element) {
+                element.required = required;
             }
         }
     }
 
-    function on_ipv4_method_change() {
-        var selected = $("input[name=ipv4_method]:checked");
-        if (selected.prop("value") == "manual") {
-            ip_required(true, 'ipv4', ['address']);
-            ip_readonly(false, 'ipv4', ['address', 'netmask', 'gateway',
+    function ipReadOnly(readOnly, ipVersion, fields) {
+        const prefix = 'id_' + ipVersion + '_';
+        for (var i = 0; i < fields.length; i++) {
+            const element = document.getElementById(prefix + fields[i]);
+            if (element) {
+                element.readOnly = readOnly;
+                if (readOnly) {
+                    element.value = "";
+                    element.required = false;
+                }
+            }
+        }
+    }
+
+    function onIpv4MethodChange() {
+        const selected = document.querySelector("input[name=ipv4_method]:checked");
+        if (selected && selected.value === "manual") {
+            ipRequired(true, 'ipv4', ['address']);
+            ipReadOnly(false, 'ipv4', ['address', 'netmask', 'gateway',
                 'dns', 'second_dns'
             ]);
-        } else if (selected.prop("value") == "shared") {
-            ip_required(false, 'ipv4', ['address']);
-            ip_readonly(false, 'ipv4', ['address', 'netmask']);
-            ip_readonly(true, 'ipv4', ['gateway', 'dns', 'second_dns']);
-        } else if (selected.prop("value") == "auto") {
-            ip_readonly(true, 'ipv4', ['address', 'netmask', 'gateway']);
-            ip_readonly(false, 'ipv4', ['dns', 'second_dns']);
+        } else if (selected && selected.value === "shared") {
+            ipRequired(false, 'ipv4', ['address']);
+            ipReadOnly(false, 'ipv4', ['address', 'netmask']);
+            ipReadOnly(true, 'ipv4', ['gateway', 'dns', 'second_dns']);
+        } else if (selected && selected.value === "auto") {
+            ipReadOnly(true, 'ipv4', ['address', 'netmask', 'gateway']);
+            ipReadOnly(false, 'ipv4', ['dns', 'second_dns']);
         } else {
-            ip_readonly(true, 'ipv4', ['address', 'netmask', 'gateway',
+            ipReadOnly(true, 'ipv4', ['address', 'netmask', 'gateway',
                 'dns', 'second_dns'
             ]);
         }
     }
 
-    function on_ipv6_method_change() {
-        var selected = $("input[name=ipv6_method]:checked");
-        if (selected.prop("value") == "manual") {
-            ip_required(true, 'ipv6', ['address', 'prefix']);
-            ip_readonly(false, 'ipv6', ['address', 'prefix', 'gateway',
+    function onIpv6MethodChange() {
+        const selected = document.querySelector("input[name=ipv6_method]:checked");
+        if (selected && selected.value === "manual") {
+            ipRequired(true, 'ipv6', ['address', 'prefix']);
+            ipReadOnly(false, 'ipv6', ['address', 'prefix', 'gateway',
                 'dns', 'second_dns'
             ]);
-        } else if (selected.prop("value") == "auto" ||
-            $("#id_ipv6_method").prop("value") == "dhcp") {
-            ip_readonly(true, 'ipv6', ['address', 'prefix', 'gateway']);
-            ip_readonly(false, 'ipv6', ['dns', 'second_dns']);
+        } else if (selected && (selected.value === "auto" ||
+                                selected.value === "dhcp")) {
+            ipReadOnly(true, 'ipv6', ['address', 'prefix', 'gateway']);
+            ipReadOnly(false, 'ipv6', ['dns', 'second_dns']);
         } else {
-            ip_readonly(true, 'ipv6', ['address', 'prefix', 'gateway',
+            ipReadOnly(true, 'ipv6', ['address', 'prefix', 'gateway',
                 'dns', 'second_dns'
             ]);
         }
     }
 
-    $("#id_name").focus();
-
-    $("input[name=ipv4_method]").change(on_ipv4_method_change).change();
-    $("input[name=ipv6_method]").change(on_ipv6_method_change).change();
-
-    $('#id_show_password').change(function() {
-        // Changing type attribute from password to text is prevented by
-        // most browsers. Making a new form field works.
-        new_type = 'password';
-        if ($('#id_show_password').prop('checked'))
-            new_type = 'text';
-
-        $('#id_password').replaceWith(
-            $('#id_password').clone().attr('type', new_type));
+    document.querySelectorAll("input[name=ipv4_method]").forEach(element => {
+        element.addEventListener('change', onIpv4MethodChange);
     });
 
+    document.querySelectorAll("input[name=ipv6_method]").forEach(element => {
+        element.addEventListener('change', onIpv6MethodChange);
+    });
+
+    onIpv4MethodChange();
+    onIpv6MethodChange();
+
+    const showPasswordElement = document.getElementById('id_show_password');
+    if (showPasswordElement) {
+        showPasswordElement.addEventListener('change', () => {
+            // Changing type attribute from password to text is prevented by
+            // most browsers. Making a new form field works.
+            var newType = 'password';
+            if (showPasswordElement.checked) {
+                newType = 'text';
+            }
+            document.getElementById('id_password').type = newType;
+        });
+    }
 });
 
 // When there are validation errors on form elements, expand their parent
@@ -104,14 +117,14 @@ jQuery(function($) {
 // can be show by the browser.
 document.addEventListener('DOMContentLoaded', event => {
     const selector = '.form-connection input, .form-connection select';
-    const input_elements = document.querySelectorAll(selector);
-    input_elements.forEach(input =>
-        input.addEventListener('invalid', on_invalid_event)
+    const inputElements = document.querySelectorAll(selector);
+    inputElements.forEach(input =>
+        input.addEventListener('invalid', onInvalidEvent)
     );
 });
 
-function on_invalid_event(event) {
-    const element = event.target;
+function onInvalidEvent(event) {
+    const element = event.currentTarget;
     const parent = element.closest('.collapse');
     // Don't use .collapse(). Instead, expand all the sections with errors.
     parent.classList.add('show');
diff --git a/plinth/modules/snapshot/static/snapshot.js b/plinth/modules/snapshot/static/snapshot.js
index d82d67f3d..c388af8e8 100644
--- a/plinth/modules/snapshot/static/snapshot.js
+++ b/plinth/modules/snapshot/static/snapshot.js
@@ -22,12 +22,15 @@
  * in this page.
  */
 
-(function($) {
-    $("#select-all").click(function() {
-        var checkedState = this.checked;
-        checkboxes = document.getElementsByName('snapshot_list');
-        jQuery.each(checkboxes, function(i, checkbox) {
-            checkbox.checked = checkedState;
+document.addEventListener('DOMContentLoaded', () => {
+    const selectAllCheckbox = document.getElementById('select-all');
+    if (selectAllCheckbox) {
+        selectAllCheckbox.addEventListener('click', (event) => {
+            const checkedState = event.currentTarget.checked;
+            const checkboxes = document.getElementsByName('snapshot_list');
+            checkboxes.forEach(checkbox => {
+                checkbox.checked = checkedState;
+            });
         });
-    });
-})(jQuery);
+    }
+});
diff --git a/plinth/modules/tor/static/tor.js b/plinth/modules/tor/static/tor.js
index b4ccad53c..927ccfda4 100644
--- a/plinth/modules/tor/static/tor.js
+++ b/plinth/modules/tor/static/tor.js
@@ -22,26 +22,38 @@
  * in this page.
  */
 
-(function($) {
-    $('#id_tor-relay_enabled').change(function() {
-        var bridge = $('#id_tor-bridge_relay_enabled');
-        var disable = !$('#id_tor-relay_enabled').prop('checked');
-        bridge.prop('disabled', disable);
-        if (disable) {
-            $('#id_tor-bridge_relay_enabled').prop('checked', false);
-        }
-    }).change();
+document.addEventListener('DOMContentLoaded', () => {
+    const relayEnabled = document.getElementById('id_tor-relay_enabled');
+    const bridgeRelay = document.getElementById('id_tor-bridge_relay_enabled');
+    const useUpstreamBridges = document.getElementById('id_tor-use_upstream_bridges');
+    const upstreamBridgesField = document.getElementById('id_tor-upstream_bridges')
+          .closest('.form-group');
 
-    $('#id_tor-use_upstream_bridges').change(function() {
-        if ($('#id_tor-use_upstream_bridges').prop('checked')) {
-            $('#id_tor-upstream_bridges').parent().parent().show('slow');
-            $('#id_tor-relay_enabled').prop('checked', false)
-                .prop('disabled', true);
-            $('#id_tor-bridge_relay_enabled').prop('checked', false)
-                .prop('disabled', true);
-        } else {
-            $('#id_tor-upstream_bridges').parent().parent().hide('slow');
-            $('#id_tor-relay_enabled').prop('disabled', false);
+    function handleRelayChange() {
+        const disable = !relayEnabled.checked;
+        bridgeRelay.disabled = disable;
+        if (disable) {
+            bridgeRelay.checked = false;
         }
-    }).change();
-})(jQuery);
+    }
+
+    function handleUseUpstreamBridgesChange() {
+        if (useUpstreamBridges.checked) {
+            upstreamBridgesField.style.display = '';
+            relayEnabled.checked = false;
+            relayEnabled.disabled = true;
+            bridgeRelay.checked = false;
+            bridgeRelay.disabled = true;
+        } else {
+            upstreamBridgesField.style.display = 'none';
+            relayEnabled.disabled = false;
+        }
+    }
+
+    relayEnabled.addEventListener('change', handleRelayChange);
+    useUpstreamBridges.addEventListener('change', handleUseUpstreamBridgesChange);
+
+    // Initial state
+    handleRelayChange();
+    handleUseUpstreamBridgesChange();
+});
diff --git a/plinth/modules/torproxy/static/torproxy.js b/plinth/modules/torproxy/static/torproxy.js
index 3469c5a88..43343f626 100644
--- a/plinth/modules/torproxy/static/torproxy.js
+++ b/plinth/modules/torproxy/static/torproxy.js
@@ -22,12 +22,20 @@
  * in this page.
  */
 
-(function($) {
-    $('#id_torproxy-use_upstream_bridges').change(function() {
-        if ($('#id_torproxy-use_upstream_bridges').prop('checked')) {
-            $('#id_torproxy-upstream_bridges').parent().parent().show('slow');
+document.addEventListener('DOMContentLoaded', () => {
+    const useUpstreamBridges = document.getElementById('id_torproxy-use_upstream_bridges');
+    const upstreamBridges = document.getElementById('id_torproxy-upstream_bridges');
+
+    function handleUseUpstreamBridgesChange() {
+        if (useUpstreamBridges.checked) {
+            upstreamBridges.closest('.form-group').style.display = '';
         } else {
-            $('#id_torproxy-upstream_bridges').parent().parent().hide('slow');
+            upstreamBridges.closest('.form-group').style.display = 'none';
         }
-    }).change();
-})(jQuery);
+    }
+
+    useUpstreamBridges.addEventListener('change', handleUseUpstreamBridgesChange);
+
+    // Initial state
+    handleUseUpstreamBridgesChange();
+});
diff --git a/plinth/templates/base.html b/plinth/templates/base.html
index 4d19a4f3f..813a476e5 100644
--- a/plinth/templates/base.html
+++ b/plinth/templates/base.html
@@ -58,9 +58,6 @@
     <link rel="stylesheet" href="{% static user_css %}"/>
   {% endif %}
 
-  <!-- Local link to system jQuery -->
-  <!-- TODO Deferring jQuery is causing scripts to be loaded before jQuery is available -->
-  <script type="text/javascript" src="{% static '/javascript/jquery/jquery.min.js' %}"></script>
   <!-- Local link to system Bootstrap JS -->
   <script type="text/javascript" src="{% static '/javascript/popper.js/umd/popper.js' %}" defer></script>
   <script type="text/javascript" src="{% static 'theme/js/fix.js' %}" defer></script>