diff --git a/javascript/active_units.js b/javascript/active_units.js
new file mode 100644
index 000000000..03b8be0af
--- /dev/null
+++ b/javascript/active_units.js
@@ -0,0 +1,73 @@
+/**
+ * [TODO] Give a badge on ControlNet Accordion indicating total number of active 
+ * units.
+ * Give a dot indicator on each ControlNet unit tab, indicating whether
+ * the unit is active.
+ */
+const cnetAllUnits = new Map/* <Element, GradioTab> */();
+
+onUiUpdate(() => {
+    function childIndex(element) {
+        // Get all child nodes of the parent
+        let children = Array.from(element.parentNode.childNodes);
+
+        // Filter out non-element nodes (like text nodes and comments)
+        children = children.filter(child => child.nodeType === Node.ELEMENT_NODE);
+
+        return children.indexOf(element);
+    }
+
+    class GradioTab {
+        constructor(tab) {
+            this.enabledCheckbox = tab.querySelector('.cnet-unit-enabled input');
+            const tabs = tab.parentNode;
+            this.tabNav = tabs.querySelector('.tab-nav');
+            this.tabIndex = childIndex(tab) - 1; // -1 because tab-nav is also at the same level.            
+
+            this.attachEnabledButtonListener();
+            this.attachTabNavChangeObserver();
+        }
+
+        getTabNavButton() {
+            return this.tabNav.querySelector(`:nth-child(${this.tabIndex + 1})`);
+        }
+        
+        applyActiveState() {
+            const tabNavButton = this.getTabNavButton();
+            if (!tabNavButton) return;
+
+            if (this.enabledCheckbox.checked) {
+                tabNavButton.classList.add('cnet-unit-active'); 
+            } else {
+                tabNavButton.classList.remove('cnet-unit-active'); 
+            }
+        }
+
+        attachEnabledButtonListener() {
+            this.enabledCheckbox.addEventListener('change', () => {
+                this.applyActiveState();
+            });
+        }
+
+        /**
+         * Each time the active tab change, all tab nav buttons are cleared and
+         * regenerated by gradio. So we need to reapply the active states on 
+         * them.
+         */
+        attachTabNavChangeObserver() {
+            const observer = new MutationObserver((mutationsList, observer) => {
+                for(const mutation of mutationsList) {
+                    if (mutation.type === 'childList') {
+                        this.applyActiveState();
+                    }
+                }
+            });
+            observer.observe(this.tabNav, { childList: true });
+        }
+    }
+
+    gradioApp().querySelectorAll('.cnet-unit-tab').forEach(tab => {
+        if (cnetAllUnits.has(tab)) return;
+        cnetAllUnits.set(tab, new GradioTab(tab));
+    });
+});
diff --git a/scripts/controlnet.py b/scripts/controlnet.py
index d4598a0cb..375395fcf 100644
--- a/scripts/controlnet.py
+++ b/scripts/controlnet.py
@@ -234,7 +234,8 @@ def ui(self, is_img2img):
                 if max_models > 1:
                     with gr.Tabs(elem_id=f"{elem_id_tabname}_tabs"):
                         for i in range(max_models):
-                            with gr.Tab(f"ControlNet Unit {i}"):
+                            with gr.Tab(f"ControlNet Unit {i}", 
+                                        elem_classes=['cnet-unit-tab']):
                                 controls += (self.uigroup(f"ControlNet-{i}", is_img2img, elem_id_tabname),)
                 else:
                     with gr.Column():
diff --git a/scripts/controlnet_ui/controlnet_ui_group.py b/scripts/controlnet_ui/controlnet_ui_group.py
index 18be13c8a..a114529ee 100644
--- a/scripts/controlnet_ui/controlnet_ui_group.py
+++ b/scripts/controlnet_ui/controlnet_ui_group.py
@@ -260,6 +260,7 @@ def render(self, tabname: str, elem_id_tabname: str) -> None:
                 label="Enable",
                 value=self.default_unit.enabled,
                 elem_id=f"{elem_id_tabname}_{tabname}_controlnet_enable_checkbox",
+                elem_classes=['cnet-unit-enabled'],
             )
             self.lowvram = gr.Checkbox(
                 label="Low VRAM",
diff --git a/style.css b/style.css
index f051f7e87..26b07d4af 100644
--- a/style.css
+++ b/style.css
@@ -104,4 +104,13 @@
     background: var(--background-fill-primary);
     height: var(--size-5);
     color: var(--block-label-text-color) !important;
+}
+
+.cnet-unit-active {
+    color: green !important;
+    font-weight: bold !important;
+}
+
+.dark .cnet-unit-active {
+    color: greenyellow !important;
 }
\ No newline at end of file