diff --git a/QualityControl/public/app.css b/QualityControl/public/app.css
index 81a6b4c29..530e2e524 100644
--- a/QualityControl/public/app.css
+++ b/QualityControl/public/app.css
@@ -248,3 +248,38 @@
     flex: 1;
   }
 }
+
+.combobox-container {
+  position: relative;
+
+  &:focus-within .combobox-list {
+    display: block;
+    width: 100%;
+  }
+
+  & .combobox-list {
+    padding: 0;
+    margin: 0;
+    padding-inline-start: 0;
+    list-style: none;
+    left: 0;
+    right: 0;
+    max-height: 250px;
+    overflow-y: auto;
+    margin-top: var(--space-xs);
+
+    & .combobox-item {
+      &:hover, &.is-highlighted {
+        background-color: var(--color-primary);
+        color: var(--color-white);
+      }
+    }
+
+    & .combobox-header {
+        padding: 4px 12px;
+        font-size: 0.85rem;
+        color: var(--color-gray-darker);
+        font-weight: bold;
+    }
+  }
+}
diff --git a/QualityControl/public/common/filters/filter.js b/QualityControl/public/common/filters/filter.js
index b92ea7df6..9ba2217ba 100644
--- a/QualityControl/public/common/filters/filter.js
+++ b/QualityControl/public/common/filters/filter.js
@@ -338,3 +338,109 @@ export const ongoingRunsSelector = (config, filterMap, options, onChangeCallback
     ),
   ]);
 };
+
+/**
+ * Renders a searchable Combobox with keyboard navigation using ALICE O2 design.
+ * This component is a stateless function that leverages CSS `:focus-within` for visibility
+ * and direct DOM manipulation for arrow-key highlighting to avoid FilterModel pollution.
+ * @param {object} config - The configuration for the combobox field.
+ * @param {string} config.id - The unique HTML ID for the input element.
+ * @param {string} config.inputType - The type for the HTML input element.
+ * @param {string} config.queryLabel - The key name in the filterMap to update.
+ * @param {string} config.placeholder - The placeholder text for the input.
+ * @param {string} config.width - Width of the input container.
+ * @param {object} filterMap - Object containing current filter keys and values.
+ * @param {RemoteData} options - RemoteData object containing the list of available options.
+ * @param {onenter} onEnterCallback - Callback to trigger filtering.
+ * @param {oninput} onInputCallback - Callback to update the filter value.
+ * @returns {vnode} - A virtual node representing the combobox.
+ */
+export const combobox = (
+  { id, inputType, queryLabel, placeholder, width = '.w-20' },
+  filterMap,
+  options,
+  onEnterCallback,
+  onInputCallback,
+) => {
+  const ongoingRuns = options.isSuccess() && options.payload.length > 0 ? options.payload : [];
+  if (!ongoingRuns.length) {
+    return filterInput({
+      queryLabel, placeholder, id, filterMap, onInputCallback, onEnterCallback, type: inputType, width,
+    });
+  }
+  const filtered = filterMap[queryLabel]
+    ? ongoingRuns?.filter((option) =>
+      String(option).toLowerCase().includes(filterMap[queryLabel].toLowerCase()))
+    : ongoingRuns;
+
+  const handleKeyNavigation = (e) => {
+    const container = e.target.closest('.combobox-container');
+    const items = [...container.querySelectorAll('.combobox-item:not(.combobox-header)')];
+    const current = container.querySelector('.is-highlighted');
+    const index = items.indexOf(current);
+
+    const move = (nextIndex) => {
+      if (current) {
+        current.classList.remove('is-highlighted');
+      }
+      if (items[nextIndex]) {
+        items[nextIndex].classList.add('is-highlighted');
+        items[nextIndex].scrollIntoView({ block: 'nearest' });
+      }
+    };
+
+    const keys = {
+      ArrowDown: () => move(Math.min(index + 1, items.length - 1)),
+      ArrowUp: () => move(Math.max(index - 1, 0)),
+      Enter: () => {
+        if (current) {
+          onInputCallback(queryLabel, current.innerText, true);
+        }
+        e.target.blur();
+      },
+    };
+
+    if (keys[e.key]) {
+      if (e.key !== 'Enter') {
+        e.preventDefault();
+      }
+      keys[e.key]();
+    }
+  };
+
+  return h(`${width}.combobox-container`, [
+    h('input.form-control', {
+      id,
+      placeholder,
+      type: inputType,
+      autocomplete: 'off',
+      min: 0,
+      value: filterMap[queryLabel] || '',
+      oninput: (event) => onInputCallback(queryLabel, event.target.value, true),
+      onkeydown: handleKeyNavigation,
+      onblur: (e) => {
+        const container = e.target.closest('.combobox-container');
+        container.querySelector('.is-highlighted')?.classList.remove('is-highlighted');
+      },
+    }),
+
+    filtered.length > 0 && h(
+      'ul.combobox-list.dropdown-menu',
+      [
+        h('li.combobox-header.dropdown-header', {
+          style: { pointerEvents: 'none', userSelect: 'none' },
+        }, placeholder),
+
+        ...filtered.map((option) =>
+          h('li.combobox-item.menu-item', {
+            onmousedown: (e) => {
+              // onmousedown to capture before blur event
+              e.preventDefault();
+              onInputCallback(queryLabel, option, true);
+              e.target.closest('.combobox-container').querySelector('input')?.blur();
+            },
+          }, option)),
+      ],
+    ),
+  ]);
+};
diff --git a/QualityControl/public/common/filters/filterTypes.js b/QualityControl/public/common/filters/filterTypes.js
index 0ac837bf3..2c4ef2baf 100644
--- a/QualityControl/public/common/filters/filterTypes.js
+++ b/QualityControl/public/common/filters/filterTypes.js
@@ -18,6 +18,7 @@ const FilterType = {
   DROPDOWN: 'dropdownSelector',
   GROUPED_DROPDOWN: 'groupedDropdownSelector',
   RUN_MODE: 'runModeSelector',
+  COMBOBOX: 'combobox',
 };
 
 export { FilterType };
diff --git a/QualityControl/public/common/filters/filterViews.js b/QualityControl/public/common/filters/filterViews.js
index da9337415..1980f66a4 100644
--- a/QualityControl/public/common/filters/filterViews.js
+++ b/QualityControl/public/common/filters/filterViews.js
@@ -18,6 +18,7 @@ import {
   ongoingRunsSelector,
   groupedDropdownComponent,
   inputWithDropdownComponent,
+  combobox,
 } from './filter.js';
 import { FilterType } from './filterTypes.js';
 import { filtersConfig, runModeFilterConfig } from './filtersConfig.js';
@@ -34,10 +35,10 @@ import { h, iconChevronBottom, iconChevronTop } from '/js/src/index.js';
  * Creates an input element for a specific metadata field;
  * @param {object} config - The configuration for this particular field
  * @param {object} filterMap - An object that contains the keys and values of the filters
- * @param {Function} onInputCallback - A callback function that triggers upon Input
- * @param {Function} onEnterCallback - A callback function that triggers upon Enter
- * @param {Function} onChangeCallback - A callback function that triggers upon Change
- * @param onFocusCallback
+ * @param {oninput} onInputCallback - A callback function that triggers upon Input
+ * @param {onenter} onEnterCallback - A callback function that triggers upon Enter
+ * @param {onchange} onChangeCallback - A callback function that triggers upon Change
+ * @param {onfocus} onFocusCallback - A callback function that triggers upon Focus
  * @returns {undefined}
  */
 const createFilterElement =
@@ -69,6 +70,8 @@ const createFilterElement =
           onEnterCallback,
           onFocusCallback,
         );
+      case FilterType.COMBOBOX:
+        return combobox({ ...config }, filterMap, options, onEnterCallback, onInputCallback);
       default: return null;
     }
   };
@@ -126,7 +129,7 @@ export function filtersPanel(filterModel, viewModel) {
 
 /**
  * Button which will allow the user to update filter parameters after the input
- * @param {Function} onClickCallback - Function to trigger the filter mechanism
+ * @param {onclick} onClickCallback - Function to trigger the filter mechanism
  * @param {FilterModel} filterModel - Model that manages filter state
  * @returns {vnode} - virtual node element
  */
@@ -149,7 +152,7 @@ const triggerFiltersButton = (onClickCallback, filterModel) => {
 
 /**
  * Button which will allow the user to clear the filter element
- * @param {Function} clearFilterCallback - Function that clears the filter state.
+ * @param {onclick} clearFilterCallback - Function that clears the filter state.
  * @returns {vnode} - virtual node element
  */
 const clearFiltersButton = (clearFilterCallback) =>
diff --git a/QualityControl/public/common/filters/filtersConfig.js b/QualityControl/public/common/filters/filtersConfig.js
index 45c2f9e75..20b2558e6 100644
--- a/QualityControl/public/common/filters/filtersConfig.js
+++ b/QualityControl/public/common/filters/filtersConfig.js
@@ -22,13 +22,14 @@ import { FilterType } from './filterTypes.js';
  * @param {RemoteData<DataPass[]>} filterService.dataPasses - data passes to show in the filter
  * @returns {object[]} Filter configuration array
  */
-export const filtersConfig = ({ runTypes, detectors, dataPasses }) => [
+export const filtersConfig = ({ runTypes, detectors, dataPasses, ongoingRuns }) => [
   {
-    type: FilterType.INPUT,
+    type: FilterType.COMBOBOX,
     queryLabel: 'RunNumber',
     placeholder: 'RunNumber (e.g. 546783)',
     id: 'runNumberFilter',
     inputType: 'number',
+    options: ongoingRuns,
   },
   {
     type: FilterType.DROPDOWN,
diff --git a/QualityControl/public/common/filters/model/FilterModel.js b/QualityControl/public/common/filters/model/FilterModel.js
index 58be9760e..3cb0582dc 100644
--- a/QualityControl/public/common/filters/model/FilterModel.js
+++ b/QualityControl/public/common/filters/model/FilterModel.js
@@ -49,6 +49,8 @@ export default class FilterModel extends Observable {
     this._runInformation = {};
 
     this.ONGOING_RUN_INTERVAL_MS = 15000;
+
+    this.filterService.fetchOngoingRuns();
   }
 
   /**
@@ -103,10 +105,14 @@ export default class FilterModel extends Observable {
    * @returns {undefined}
    */
   setFilterValue(key, value, setUrl = false) {
-    if (value?.trim()) {
-      this._filterMap[key] = value;
-    } else {
-      delete this._filterMap[key];
+    if (typeof value === 'string') {
+      if (value && value?.trim()) {
+        this._filterMap[key] = value;
+      } else {
+        delete this._filterMap[key];
+      }
+    } else if (typeof value === 'number') {
+      this._filterMap[key] = String(value);
     }
 
     if (setUrl) {
@@ -187,9 +193,11 @@ export default class FilterModel extends Observable {
    */
   async activateRunsMode(viewModel) {
     this.isRunModeActivated = true;
-    await this.filterService.fetchOngoingRuns();
-    if (this._filterMap.RunNumber) {
-      this._filterMap = { RunNumber: this._filterMap.RunNumber };
+    const { RunNumber } = this._filterMap;
+    this.clearFilters();
+
+    if (RunNumber) {
+      this._filterMap = { RunNumber };
       this.triggerFilter(viewModel);
     } else {
       const { ongoingRuns } = this.filterService;
diff --git a/QualityControl/public/services/Filter.service.js b/QualityControl/public/services/Filter.service.js
index 0758cfaa6..d976ca6c8 100644
--- a/QualityControl/public/services/Filter.service.js
+++ b/QualityControl/public/services/Filter.service.js
@@ -31,7 +31,7 @@ export default class FilterService {
     this._detectors = RemoteData.notAsked();
     this._dataPasses = RemoteData.notAsked();
 
-    this.ongoingRuns = RemoteData.notAsked();
+    this._ongoingRuns = RemoteData.notAsked();
   }
 
   /**
@@ -104,13 +104,13 @@ export default class FilterService {
    * @returns {void} assigns the remoteData object to ongoingRuns
    */
   async fetchOngoingRuns() {
-    this.ongoingRuns = RemoteData.loading();
+    this._ongoingRuns = RemoteData.loading();
     this.filterModel.notify();
     const { result, ok } = await this.loader.get('/api/filter/ongoingRuns');
     if (ok) {
-      this.ongoingRuns = RemoteData.success(result?.ongoingRuns);
+      this._ongoingRuns = RemoteData.success(result?.ongoingRuns);
     } else {
-      this.ongoingRuns = RemoteData.failure('Error retrieving ongoing runs');
+      this._ongoingRuns = RemoteData.failure('Error retrieving ongoing runs');
     }
     this.filterModel.notify();
   }
@@ -138,4 +138,12 @@ export default class FilterService {
   get dataPasses() {
     return this._dataPasses;
   }
+
+  /**
+   * Gets the list of ongoing runs.
+   * @returns {RemoteData<number[]>} An array containing the ongoing run numbers.
+   */
+  get ongoingRuns() {
+    return this._ongoingRuns;
+  }
 }
diff --git a/QualityControl/test/public/features/filterTest.test.js b/QualityControl/test/public/features/filterTest.test.js
index 39ac31d67..4d585d989 100644
--- a/QualityControl/test/public/features/filterTest.test.js
+++ b/QualityControl/test/public/features/filterTest.test.js
@@ -44,7 +44,7 @@ export const filterTests = async (url, page, timeout = 5000, testParent) => {
     strictEqual(value, '0', 'RunNumber filter should still be set to 0 on objectView page');
 
     // Navigate to layout show
-    await page.locator('.menu-item:nth-child(1)').click();
+    await page.locator('nav .menu-item:nth-child(1)').click();
     await page.waitForSelector('#runNumberFilter', { visible: true });
 
     // Check that filter is still set to 0
diff --git a/QualityControl/test/public/features/runMode.test.js b/QualityControl/test/public/features/runMode.test.js
index 9d8bada41..1b2772df7 100644
--- a/QualityControl/test/public/features/runMode.test.js
+++ b/QualityControl/test/public/features/runMode.test.js
@@ -23,7 +23,6 @@ import { ONGOING_RUN_NUMBER } from '../../setup/mockKafkaEvents.js';
 // import nock from 'nock';
 export const runModeTests = async (url, page, timeout = 5000, testParent) => {
   const mockedTestRunNumber = ONGOING_RUN_NUMBER;
-  let countOngoingRunsCalls = 0;
   let countRunStatusCalls = 0;
   let expectCountRunStatusCalls = 0;
   let countObjectsCalls = 0;
@@ -31,9 +30,6 @@ export const runModeTests = async (url, page, timeout = 5000, testParent) => {
   page.on('request', (req) => {
     const url = req.url();
     const decodedUrl = decodeURIComponent(url);
-    if (url.includes('/api/filter/ongoingRuns')) {
-      countOngoingRunsCalls++;
-    }
     if (url.includes('/api/objects') && decodedUrl.includes(`filters[RunNumber]=${mockedTestRunNumber}`)) {
       countObjectsCalls++;
     } else if (url.includes(`/api/filter/run-status/${mockedTestRunNumber}`)) {
@@ -167,11 +163,6 @@ export const runModeTests = async (url, page, timeout = 5000, testParent) => {
     ok(isRunModeActivated, 'Run mode should be activated');
   });
 
-  await testParent.test('should make a request to ongoing runs API', { timeout }, async () => {
-    await delay(200);
-    strictEqual(countOngoingRunsCalls, expectCountRunStatusCalls, `Expect 1 req to /api/filter/ongoingRuns, but got ${countOngoingRunsCalls}`);
-  });
-
   await testParent.test('should display ongoing runs selector', { timeout }, async () => {
     await page.waitForSelector('#ongoingRunsFilter', { timeout: 1000 });
     const selector = await page.locator('#ongoingRunsFilter');
diff --git a/QualityControl/test/public/initialPageSetup.test.js b/QualityControl/test/public/initialPageSetup.test.js
index aa81f3f6a..ad5ef2bd5 100644
--- a/QualityControl/test/public/initialPageSetup.test.js
+++ b/QualityControl/test/public/initialPageSetup.test.js
@@ -12,7 +12,7 @@
  * or submit itself to any jurisdiction.
  */
 
-import assert from 'node:assert';
+import { strictEqual, ok } from 'node:assert';
 
 /**
  * Initial page setup tests
@@ -41,14 +41,32 @@ export const initialPageSetupTests = async (url, page, timeout = 1000, testParen
 
   await testParent.test('should successfully have redirected to default page "/?page=layoutList"', async () => {
     const location = await page.evaluate(() => window.location);
-    assert.strictEqual(location.search, '?page=layoutList');
+    strictEqual(location.search, '?page=layoutList');
   });
 
   await testParent.test('should have a layout with header, sidebar and section', async () => {
     const headerContent = await page.evaluate(() => document.querySelector('header').innerHTML);
     const sidebarContent = await page.evaluate(() => document.querySelector('nav').innerHTML);
 
-    assert.ok(headerContent.includes('Quality Control'));
-    assert.ok(sidebarContent.includes('Explore'));
+    ok(headerContent.includes('Quality Control'));
+    ok(sidebarContent.includes('Explore'));
+  });
+
+  await testParent.test('should make a request to ongoing runs API on page load', { timeout }, async () => {
+    let countOngoingRunsCalls = 0;
+
+    page.on('request', (req) => {
+      const url = req.url();
+      if (url.includes('/api/filter/ongoingRuns')) {
+        countOngoingRunsCalls++;
+      }
+    });
+
+    await page.goto(
+      `${url}?page=objectTree`,
+      { waitUntil: 'networkidle0' },
+    );
+
+    strictEqual(countOngoingRunsCalls, 1, `Expect 1 req to /api/filter/ongoingRuns, but got ${countOngoingRunsCalls}`);
   });
 };