diff --git a/css/experiments-filter.css b/css/experiments-filter.css
new file mode 100644
index 0000000..2871d91
--- /dev/null
+++ b/css/experiments-filter.css
@@ -0,0 +1,24 @@
+/**
+ * @file
+ * Lays out the experiments overview filter as one aligned row.
+ */
+
+.rl-experiments-filter {
+  display: flex;
+  flex-wrap: wrap;
+  align-items: flex-end;
+  gap: 0.75rem 1rem;
+}
+
+/* Reset the theme margins so labels, fields and buttons share one grid. */
+.rl-experiments-filter .form-item,
+.rl-experiments-filter .form-actions,
+.rl-experiments-filter .form-actions .button {
+  margin: 0;
+}
+
+.rl-experiments-filter .form-actions {
+  display: flex;
+  align-items: flex-end;
+  gap: 0.5rem;
+}
diff --git a/docs/getting-started/configuration.md b/docs/getting-started/configuration.md
index bc05001..d913a0a 100644
--- a/docs/getting-started/configuration.md
+++ b/docs/getting-started/configuration.md
@@ -66,6 +66,11 @@ per-experiment performance, traffic distribution, and confidence levels.
 
 ![RL experiment list showing impressions, conversions, and variant counts](../images/rl-experiment-list.jpg)
 
+Above the list, search by experiment name or ID, or filter by **Source** (the
+module that registered the experiment) and **Activity** (with or without
+impressions). The filters combine, work with column sorting and paging, and
+stay in the page address, so a filtered list can be bookmarked or shared.
+
 Click **View** on any experiment to see its detail page with interactive
 charts. The 2D line chart shows conversion scores over time; the 3D
 posterior landscape visualises how Thompson Sampling distributions evolve
diff --git a/rl.libraries.yml b/rl.libraries.yml
index caf99a9..1b42c1c 100644
--- a/rl.libraries.yml
+++ b/rl.libraries.yml
@@ -12,6 +12,12 @@ experiment-highlight:
     theme:
       css/experiment-highlight.css: {}
 
+experiments-filter:
+  version: 1.0
+  css:
+    component:
+      css/experiments-filter.css: {}
+
 plotly:
   version: 2.35.2
   license:
diff --git a/rl.routing.yml b/rl.routing.yml
index 401e8fa..91d7136 100644
--- a/rl.routing.yml
+++ b/rl.routing.yml
@@ -1,7 +1,7 @@
 rl.reports.experiments:
   path: '/admin/reports/rl'
   defaults:
-    _form: '\Drupal\rl\Form\ExperimentsOverviewForm'
+    _controller: '\Drupal\rl\Controller\ReportsController::experimentsOverview'
     _title: 'RL: A/B Testing'
   requirements:
     _permission: 'view rl reports'
diff --git a/scripts/e2e/overview-rows.php b/scripts/e2e/overview-rows.php
new file mode 100644
index 0000000..7814674
--- /dev/null
+++ b/scripts/e2e/overview-rows.php
@@ -0,0 +1,26 @@
+<?php
+
+/**
+ * @file
+ * Renders the RL experiments overview and filter forms for a query string.
+ *
+ * Usage: drush php:script overview-rows.php "search=hero&source=module"
+ * Prints the listed experiment names, the summary line and the reset state.
+ */
+
+use Drupal\rl\Form\ExperimentsFilterForm;
+use Drupal\rl\Form\ExperimentsOverviewForm;
+use Drupal\user\Entity\User;
+
+parse_str($extra[0] ?? '', $query);
+\Drupal::service('account_switcher')->switchTo(User::load(1));
+// Keep the CLI request, which carries the session, and swap in the query.
+\Drupal::requestStack()->push(\Drupal::request()->duplicate($query));
+
+$overview = \Drupal::formBuilder()->getForm(ExperimentsOverviewForm::class);
+$filters = \Drupal::formBuilder()->getForm(ExperimentsFilterForm::class);
+
+print 'names: ' . implode('|', array_column($overview['#experiments'], 'name')) . "\n";
+print 'summary: ' . (isset($overview['summary']) ? strip_tags((string) $overview['summary']['#markup']) : '-') . "\n";
+print 'empty: ' . strip_tags((string) $overview['experiments']['#empty']) . "\n";
+print 'reset: ' . (isset($filters['actions']['reset']) ? 'yes' : 'no') . "\n";
diff --git a/scripts/e2e/test-experiments-overview.sh b/scripts/e2e/test-experiments-overview.sh
new file mode 100755
index 0000000..d051787
--- /dev/null
+++ b/scripts/e2e/test-experiments-overview.sh
@@ -0,0 +1,73 @@
+#!/usr/bin/env bash
+# E2E tests for the experiments overview search and filters.
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+source "$SCRIPT_DIR/_helpers.sh"
+
+DRUSH="${DRUSH:-drush}"
+
+# Prints one field of the overview for a query string; names come sorted.
+overview() {
+  local query="$1" field="$2" out
+  out=$($DRUSH php:script "$SCRIPT_DIR/overview-rows.php" -- "$query" 2>&1)
+  local line
+  line=$(echo "$out" | sed -n "s/^$field: //p")
+  if [ "$field" = "names" ]; then
+    echo "$line" | tr '|' '\n' | sort | paste -sd'|' -
+  else
+    echo "$line"
+  fi
+}
+
+section "Setup"
+
+$DRUSH rl:experiment:create e2e_filter_hero --module=e2e_filter_a --name="E2E Filter Hero Headline" > /dev/null
+$DRUSH rl:experiment:create e2e_filter_pricing --module=e2e_filter_a --name="E2E Filter Pricing CTA" > /dev/null
+$DRUSH rl:experiment:create e2e_filter_footer --module=e2e_filter_b --name="E2E Filter Footer Box" > /dev/null
+$DRUSH php:eval '$s = \Drupal::service("rl.experiment_data_storage"); foreach (["e2e_filter_hero" => 3, "e2e_filter_footer" => 2] as $id => $n) { for ($i = 0; $i < $n; $i++) { $s->recordTurn($id, "v0"); } }'
+
+HERO="E2E Filter Hero Headline"
+PRICING="E2E Filter Pricing CTA"
+FOOTER="E2E Filter Footer Box"
+ALL="$FOOTER|$HERO|$PRICING"
+
+section "Search"
+
+assert_eq "search by name part" "$HERO" "$(overview 'search=filter%20hero' names)"
+assert_eq "search ignores case" "$PRICING" "$(overview 'search=FILTER%20PRICING' names)"
+assert_eq "search matches the ID" "$FOOTER" "$(overview 'search=e2e_filter_footer' names)"
+assert_eq "search trims whitespace" "$HERO" "$(overview 'search=%20%20filter%20hero%20%20' names)"
+assert_eq "no match lists nothing" "" "$(overview 'search=no-such-experiment' names)"
+assert_has "no match explains itself" "No experiments match the filters." "$(overview 'search=no-such-experiment' empty)"
+
+section "Source and activity"
+
+assert_eq "source filter" "$HERO|$PRICING" "$(overview 'search=e2e_filter&source=e2e_filter_a' names)"
+assert_eq "activity with impressions" "$FOOTER|$HERO" "$(overview 'search=e2e_filter&activity=active' names)"
+assert_eq "activity without impressions" "$PRICING" "$(overview 'search=e2e_filter&activity=idle' names)"
+assert_eq "filters combine" "$PRICING" "$(overview 'search=e2e_filter&source=e2e_filter_a&activity=idle' names)"
+assert_eq "filters narrow, never widen" "" "$(overview 'search=e2e_filter&source=e2e_filter_b&activity=idle' names)"
+assert_eq "unknown source is ignored" "$ALL" "$(overview 'search=e2e_filter&source=gone' names)"
+assert_eq "unknown activity is ignored" "$ALL" "$(overview 'search=e2e_filter&activity=bogus' names)"
+
+section "Summary and reset"
+
+assert_has "summary counts matches" "Showing 2 of" "$(overview 'search=e2e_filter&source=e2e_filter_a' summary)"
+assert_eq "no summary without filters" "-" "$(overview '' summary)"
+assert_eq "reset shown while filtering" "yes" "$(overview 'search=filter%20hero' reset)"
+assert_eq "reset hidden without filters" "no" "$(overview '' reset)"
+assert_eq "a search for 0 counts as a filter" "yes" "$(overview 'search=0' reset)"
+
+section "Malformed input"
+
+assert_success "array search does not fail" $DRUSH php:script "$SCRIPT_DIR/overview-rows.php" -- 'search[]=x'
+assert_success "nested array source does not fail" $DRUSH php:script "$SCRIPT_DIR/overview-rows.php" -- 'source[a][b]=x'
+
+section "Cleanup"
+
+for id in e2e_filter_hero e2e_filter_pricing e2e_filter_footer; do
+  assert_has "delete $id" "success: true" "$($DRUSH rl:experiment:delete "$id" 2>&1)"
+done
+
+print_summary
diff --git a/src/Controller/ReportsController.php b/src/Controller/ReportsController.php
index 911c283..40faa68 100644
--- a/src/Controller/ReportsController.php
+++ b/src/Controller/ReportsController.php
@@ -9,6 +9,7 @@
 use Drupal\Core\Url;
 use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
 use Drupal\rl\Decorator\ExperimentDecoratorManager;
+use Drupal\rl\Form\ExperimentsFilterForm;
 use Drupal\rl\Form\ExperimentsOverviewForm;
 use Drupal\rl\Registry\ExperimentRegistryInterface;
 use Drupal\rl\Service\ArmDataValidator;
@@ -123,13 +124,26 @@ public static function create(ContainerInterface $container): static {
   }
 
   /**
-   * Overview page showing all experiments.
+   * Overview page showing all experiments, with filters above the list.
    *
    * @return array
    *   A render array.
    */
   public function experimentsOverview() {
-    return $this->formBuilder()->getForm(ExperimentsOverviewForm::class);
+    return [
+      'add' => [
+        '#type' => 'link',
+        '#title' => $this->t('Add experiment'),
+        '#url' => Url::fromRoute('rl.experiment.add'),
+        '#attributes' => ['class' => ['button', 'button--primary']],
+        '#access' => $this->currentUser()->hasPermission('administer rl experiments'),
+      ],
+      'description' => [
+        '#markup' => '<p>' . $this->t('Deleting an experiment resets its data. Experiments auto-recreate on next render.') . '</p>',
+      ],
+      'filters' => $this->formBuilder()->getForm(ExperimentsFilterForm::class),
+      'overview' => $this->formBuilder()->getForm(ExperimentsOverviewForm::class),
+    ];
   }
 
   /**
diff --git a/src/Form/ExperimentDeleteMultipleForm.php b/src/Form/ExperimentDeleteMultipleForm.php
index 8493f02..7151045 100644
--- a/src/Form/ExperimentDeleteMultipleForm.php
+++ b/src/Form/ExperimentDeleteMultipleForm.php
@@ -83,8 +83,9 @@ public function getConfirmText() {
    * {@inheritdoc}
    */
   public function getCancelUrl(): Url {
+    $keep = array_merge(['order', 'sort', 'page'], ExperimentsFilterForm::FILTER_KEYS);
     return Url::fromRoute('rl.reports.experiments', [], [
-      'query' => array_intersect_key($this->getRequest()->query->all(), array_flip(['order', 'sort', 'page'])),
+      'query' => array_intersect_key($this->getRequest()->query->all(), array_flip($keep)),
     ]);
   }
 
diff --git a/src/Form/ExperimentsFilterForm.php b/src/Form/ExperimentsFilterForm.php
new file mode 100644
index 0000000..7abcc4d
--- /dev/null
+++ b/src/Form/ExperimentsFilterForm.php
@@ -0,0 +1,156 @@
+<?php
+
+namespace Drupal\rl\Form;
+
+use Drupal\Core\Form\FormBase;
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\Url;
+use Drupal\rl\Registry\ExperimentRegistryInterface;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+use Symfony\Component\HttpFoundation\Request;
+
+/**
+ * Filters the experiments overview by keywords, source and activity.
+ *
+ * Submitting redirects to the overview with the filters in the URL, so
+ * filtered lists can be bookmarked, paged, sorted and shared.
+ */
+final class ExperimentsFilterForm extends FormBase {
+
+  /**
+   * Query parameters that hold the filters.
+   */
+  const FILTER_KEYS = ['search', 'source', 'activity'];
+
+  /**
+   * Constructs the experiments filter form.
+   */
+  public function __construct(
+    protected ExperimentRegistryInterface $experimentRegistry,
+  ) {}
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container): static {
+    return new static($container->get('rl.experiment_registry'));
+  }
+
+  /**
+   * Reads the filters from the query string.
+   *
+   * @param \Symfony\Component\HttpFoundation\Request $request
+   *   The request.
+   *
+   * @return string[]
+   *   The search, source and activity filters; empty strings when unset.
+   */
+  public static function getFilters(Request $request): array {
+    $query = $request->query->all();
+    $filters = [];
+    foreach (self::FILTER_KEYS as $key) {
+      $filters[$key] = isset($query[$key]) && is_string($query[$key]) ? trim($query[$key]) : '';
+    }
+    if (!in_array($filters['activity'], ['active', 'idle'], TRUE)) {
+      $filters['activity'] = '';
+    }
+    return $filters;
+  }
+
+  /**
+   * Tells whether any filter is set; a search for "0" counts as set.
+   *
+   * @param string[] $filters
+   *   The filters from ::getFilters().
+   */
+  public static function isFiltered(array $filters): bool {
+    return count(array_filter($filters, static fn (string $value): bool => $value !== '')) > 0;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getFormId(): string {
+    return 'rl_experiments_filter';
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function buildForm(array $form, FormStateInterface $form_state): array {
+    $filters = self::getFilters($this->getRequest());
+    $sources = array_filter(array_unique($this->experimentRegistry->getAll()));
+    natcasesort($sources);
+    $sources = array_combine($sources, $sources);
+
+    $form['#attributes']['class'][] = 'rl-experiments-filter';
+    $form['#attached']['library'][] = 'rl/experiments-filter';
+    $form['search'] = [
+      '#type' => 'textfield',
+      '#title' => $this->t('Name or ID'),
+      '#size' => 30,
+      '#maxlength' => 255,
+      '#default_value' => $filters['search'],
+    ];
+    $form['source'] = [
+      '#type' => 'select',
+      '#title' => $this->t('Source'),
+      '#options' => $sources,
+      '#empty_option' => $this->t('- Any -'),
+      '#default_value' => isset($sources[$filters['source']]) ? $filters['source'] : '',
+    ];
+    $form['activity'] = [
+      '#type' => 'select',
+      '#title' => $this->t('Activity'),
+      '#options' => [
+        'active' => $this->t('With impressions'),
+        'idle' => $this->t('No impressions yet'),
+      ],
+      '#empty_option' => $this->t('- Any -'),
+      '#default_value' => $filters['activity'],
+    ];
+    $form['actions'] = ['#type' => 'actions'];
+    $form['actions']['submit'] = [
+      '#type' => 'submit',
+      '#value' => $this->t('Filter'),
+    ];
+    if (self::isFiltered($filters)) {
+      $form['actions']['reset'] = [
+        '#type' => 'link',
+        '#title' => $this->t('Reset'),
+        '#url' => Url::fromRoute('rl.reports.experiments', [], ['query' => $this->getSortQuery()]),
+        '#attributes' => ['class' => ['button']],
+      ];
+    }
+    return $form;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function submitForm(array &$form, FormStateInterface $form_state): void {
+    $query = [];
+    foreach (self::FILTER_KEYS as $key) {
+      $value = trim((string) $form_state->getValue($key));
+      if ($value !== '') {
+        $query[$key] = $value;
+      }
+    }
+    // A new filter starts on the first page and keeps the chosen sort order.
+    $form_state->setIgnoreDestination();
+    $form_state->setRedirect('rl.reports.experiments', [], [
+      'query' => $query + $this->getSortQuery(),
+    ]);
+  }
+
+  /**
+   * Returns the sort parameters of the current request.
+   */
+  protected function getSortQuery(): array {
+    return array_filter(
+      array_intersect_key($this->getRequest()->query->all(), array_flip(['order', 'sort'])),
+      'is_string',
+    );
+  }
+
+}
diff --git a/src/Form/ExperimentsOverviewForm.php b/src/Form/ExperimentsOverviewForm.php
index ab9ca7a..96cdacb 100644
--- a/src/Form/ExperimentsOverviewForm.php
+++ b/src/Form/ExperimentsOverviewForm.php
@@ -83,6 +83,13 @@ public function buildForm(array $form, FormStateInterface $form_state): array {
       // IDs may contain brackets or be "0"; use safe, non-numeric form keys.
       $experiments['experiment_' . hash('sha256', $experiment->experiment_id)] = $experiment;
     }
+    $registered = $experiments;
+    $filters = ExperimentsFilterForm::getFilters($this->getRequest());
+    // Ignore a source that no longer exists, as the filter form shows "Any".
+    if (!in_array($filters['source'], array_column($registered, 'module'), TRUE)) {
+      $filters['source'] = '';
+    }
+    $experiments = array_filter($experiments, fn (object $experiment): bool => $this->matchesFilters($experiment, $filters));
     $sort = TableSort::getContextFromRequest($header, $this->getRequest());
     $field = $sort['sql'];
     uasort($experiments, static function (object $a, object $b) use ($field, $sort): int {
@@ -100,20 +107,19 @@ public function buildForm(array $form, FormStateInterface $form_state): array {
     // tableselect validation can process them. Never trust submitted labels.
     $submitted = $form_state->getUserInput()['experiments'] ?? [];
     if ($can_administer && $this->getRequest()->isMethod('POST') && is_array($submitted)) {
-      $page += array_intersect_key($experiments, $submitted);
+      $page += array_intersect_key($registered, $submitted);
     }
     $experiments = $page;
 
-    $form['add'] = [
-      '#type' => 'link',
-      '#title' => $this->t('Add experiment'),
-      '#url' => Url::fromRoute('rl.experiment.add'),
-      '#attributes' => ['class' => ['button', 'button--primary']],
-      '#access' => $can_administer,
-    ];
-    $form['description'] = [
-      '#markup' => '<p>' . $this->t('Deleting an experiment resets its data. Experiments auto-recreate on next render.') . '</p>',
-    ];
+    $filtered = ExperimentsFilterForm::isFiltered($filters);
+    if ($filtered) {
+      $form['summary'] = [
+        '#markup' => '<p>' . $this->t('Showing @shown of @total experiments.', [
+          '@shown' => $pager->getTotalItems(),
+          '@total' => count($registered),
+        ]) . '</p>',
+      ];
+    }
     $form['selection_help'] = [
       '#markup' => '<p>' . $this->t('Select experiments on this page to apply an action.') . '</p>',
       '#access' => $can_administer && !empty($experiments),
@@ -173,7 +179,7 @@ public function buildForm(array $form, FormStateInterface $form_state): array {
     $form['experiments'] = [
       '#type' => $can_administer ? 'tableselect' : 'table',
       '#header' => $header,
-      '#empty' => $this->t('No experiments found.'),
+      '#empty' => $filtered ? $this->t('No experiments match the filters.') : $this->t('No experiments found.'),
     ];
     if ($can_administer) {
       // Core tableselect uses this title for accessible checkbox labels.
@@ -218,10 +224,37 @@ public function submitForm(array &$form, FormStateInterface $form_state): void {
     $this->tempStoreFactory->get('rl_experiment_delete_multiple')->set($token, $form_state->get('selection'));
     // Defer the destination until after confirmation, as in a multi-step form.
     $form_state->setIgnoreDestination();
-    $query = array_intersect_key($this->getRequest()->query->all(), array_flip(['order', 'sort', 'page', 'destination']));
+    $keep = array_merge(['order', 'sort', 'page', 'destination'], ExperimentsFilterForm::FILTER_KEYS);
+    $query = array_intersect_key($this->getRequest()->query->all(), array_flip($keep));
     $form_state->setRedirect('rl.experiment.delete_multiple', ['selection' => $token], [
       'query' => $query,
     ]);
   }
 
+  /**
+   * Checks an experiment against the search, source and activity filters.
+   *
+   * @param object $experiment
+   *   An experiment row with a display name and statistics.
+   * @param string[] $filters
+   *   The filters from ExperimentsFilterForm::getFilters().
+   */
+  protected function matchesFilters(object $experiment, array $filters): bool {
+    if ($filters['search'] !== '') {
+      $haystacks = [$experiment->experiment_name, $experiment->experiment_id];
+      if (!array_filter($haystacks, static fn (string $text): bool => mb_stripos($text, $filters['search']) !== FALSE)) {
+        return FALSE;
+      }
+    }
+    if ($filters['source'] !== '' && $experiment->module !== $filters['source']) {
+      return FALSE;
+    }
+    $has_impressions = (int) $experiment->total_turns > 0;
+    return match ($filters['activity']) {
+      'active' => $has_impressions,
+      'idle' => !$has_impressions,
+      default => TRUE,
+    };
+  }
+
 }