diff --git a/app/main.py b/app/main.py
index 1684301..d235cb3 100644
--- a/app/main.py
+++ b/app/main.py
@@ -14,6 +14,8 @@ import logging
 import json
 import pathlib
 import re
+from urllib import request as urlrequest
+from urllib import error as urlerror
 from watchfiles import DefaultFilter, Change, awatch
 
 from ytdl import DownloadQueueNotifier, DownloadQueue, Download
@@ -586,6 +588,66 @@ async def set_hasharr_settings(request):
     config.HASHARR_TIMEOUT_SEC = timeout_sec
     return web.Response(text=serializer.encode({'status': 'ok'}), content_type='application/json')
 
+@routes.post(config.URL_PREFIX + 'hasharr-settings/test')
+async def test_hasharr_settings(request):
+    post = await _read_json_request(request)
+    url = str(post.get('url', config.HASHARR_URL)).strip()
+    service_id = int(post.get('service_id', config.HASHARR_SERVICE_ID))
+    timeout_sec = int(post.get('timeout_sec', config.HASHARR_TIMEOUT_SEC))
+    if not url:
+        raise web.HTTPBadRequest(reason='url is required')
+    if service_id <= 0:
+        raise web.HTTPBadRequest(reason='service_id must be > 0')
+    if timeout_sec <= 0:
+        raise web.HTTPBadRequest(reason='timeout_sec must be > 0')
+
+    base_url = url.rstrip('/')
+    profile_url = f"{base_url}/v1/hash-service-profiles/{service_id}"
+
+    def _fetch_profile():
+        req = urlrequest.Request(profile_url, method='GET')
+        with urlrequest.urlopen(req, timeout=timeout_sec) as resp:
+            body = resp.read().decode('utf-8', errors='replace')
+            return resp.status, body
+
+    try:
+        status, body = await asyncio.get_running_loop().run_in_executor(None, _fetch_profile)
+        if status != 200:
+            return web.json_response({
+                'status': 'error',
+                'reachable': True,
+                'valid_service_id': False,
+                'message': f'hasharr responded with status {status}',
+            }, status=502)
+        profile = json.loads(body)
+        return web.json_response({
+            'status': 'ok',
+            'reachable': True,
+            'valid_service_id': True,
+            'profile': profile,
+        })
+    except urlerror.HTTPError as exc:
+        if exc.code == 404:
+            return web.json_response({
+                'status': 'ok',
+                'reachable': True,
+                'valid_service_id': False,
+                'message': f'Service ID {service_id} was not found in hasharr.',
+            })
+        return web.json_response({
+            'status': 'error',
+            'reachable': True,
+            'valid_service_id': False,
+            'message': f'hasharr returned HTTP {exc.code}',
+        }, status=502)
+    except Exception as exc:
+        return web.json_response({
+            'status': 'error',
+            'reachable': False,
+            'valid_service_id': False,
+            'message': f'Could not reach hasharr: {exc}',
+        }, status=502)
+
 @sio.event
 async def connect(sid, environ):
     log.info(f"Client connected: {sid}")
diff --git a/ui/src/app/app.html b/ui/src/app/app.html
index 22be60d..87c110e 100644
--- a/ui/src/app/app.html
+++ b/ui/src/app/app.html
@@ -477,10 +477,30 @@
                       <button type="button" class="btn btn-secondary" (click)="saveHasharrSettings()">
                         Save Hasharr Settings
                       </button>
+                      <button type="button" class="btn btn-outline-secondary ms-2" (click)="testHasharrService()">
+                        Test Service
+                      </button>
                       @if (hasharrSettingsStatus) {
                         <span class="ms-3 text-muted">{{ hasharrSettingsStatus }}</span>
                       }
                     </div>
+                    @if (hasharrTestStatus) {
+                      <div class="col-12">
+                        <small class="text-muted">{{ hasharrTestStatus }}</small>
+                      </div>
+                    }
+                    @if (hasharrTestProfile) {
+                      <div class="col-12">
+                        <div class="small text-muted">
+                          <div><strong>Profile Name:</strong> {{ hasharrTestProfile['name'] }}</div>
+                          <div><strong>Enabled:</strong> {{ hasharrTestProfile['enabled'] }}</div>
+                          <div><strong>Apply Actions:</strong> {{ hasharrTestProfile['applyActions'] }}</div>
+                          <div><strong>Stash Index:</strong> {{ hasharrTestProfile['stashIndex'] }}</div>
+                          <div><strong>Max Time Delta:</strong> {{ hasharrTestProfile['maxTimeDelta'] }}</div>
+                          <div><strong>Max Distance:</strong> {{ hasharrTestProfile['maxDistance'] }}</div>
+                        </div>
+                      </div>
+                    }
                   </div>
                   <div class="row g-3">
                     <div class="col-md-4">
diff --git a/ui/src/app/app.ts b/ui/src/app/app.ts
index f909c4e..aac0ea6 100644
--- a/ui/src/app/app.ts
+++ b/ui/src/app/app.ts
@@ -10,7 +10,7 @@ import { NgSelectModule } from '@ng-select/ng-select';
 import { faTrashAlt, faCheckCircle, faTimesCircle, faRedoAlt, faSun, faMoon, faCheck, faCircleHalfStroke, faDownload, faExternalLinkAlt, faFileImport, faFileExport, faCopy, faClock, faTachometerAlt, faSortAmountDown, faSortAmountUp, faChevronRight, faChevronDown, faUpload } from '@fortawesome/free-solid-svg-icons';
 import { faGithub } from '@fortawesome/free-brands-svg-icons';
 import { CookieService } from 'ngx-cookie-service';
-import { AddDownloadPayload, DownloadsService, HasharrSettings } from './services/downloads.service';
+import { AddDownloadPayload, DownloadsService, HasharrSettings, HasharrServiceTestResponse } from './services/downloads.service';
 import { Themes } from './theme';
 import {
   Download,
@@ -101,6 +101,8 @@ export class App implements AfterViewInit, OnInit, OnDestroy {
   hasharrServiceID = 1;
   hasharrTimeoutSec = 20;
   hasharrSettingsStatus = '';
+  hasharrTestStatus = '';
+  hasharrTestProfile: Record<string, unknown> | null = null;
   sortAscending = false;
   expandedErrors: Set<string> = new Set<string>();
   cachedSortedDone: [string, Download][] = [];
@@ -332,6 +334,43 @@ export class App implements AfterViewInit, OnInit, OnDestroy {
     });
   }
 
+  testHasharrService() {
+    this.hasharrTestStatus = 'Testing hasharr service...';
+    this.hasharrTestProfile = null;
+    this.cdr.markForCheck();
+    this.downloads.testHasharrSettings({
+      url: String(this.hasharrUrl || '').trim(),
+      service_id: Math.max(1, Number(this.hasharrServiceID || 1)),
+      timeout_sec: Math.max(1, Number(this.hasharrTimeoutSec || 20)),
+    }).pipe(takeUntilDestroyed(this.destroyRef)).subscribe({
+      next: (resp) => {
+        if (!resp || typeof resp !== 'object' || ('status' in resp && resp.status === 'error')) {
+          this.hasharrTestStatus = 'Hasharr test failed.';
+          this.hasharrTestProfile = null;
+          this.cdr.markForCheck();
+          return;
+        }
+        const result = resp as HasharrServiceTestResponse;
+        if (result.valid_service_id) {
+          this.hasharrTestStatus = 'Hasharr reachable. Service ID is valid.';
+          this.hasharrTestProfile = result.profile || null;
+        } else if (result.reachable) {
+          this.hasharrTestStatus = result.message || 'Hasharr reachable, but service ID is not valid.';
+          this.hasharrTestProfile = null;
+        } else {
+          this.hasharrTestStatus = result.message || 'Could not reach hasharr.';
+          this.hasharrTestProfile = null;
+        }
+        this.cdr.markForCheck();
+      },
+      error: () => {
+        this.hasharrTestStatus = 'Hasharr test failed.';
+        this.hasharrTestProfile = null;
+        this.cdr.markForCheck();
+      },
+    });
+  }
+
   ngAfterViewInit() {
     this.downloads.queueChanged.pipe(takeUntilDestroyed(this.destroyRef)).subscribe(() => {
       this.queueMasterCheckbox()?.selectionChanged();
diff --git a/ui/src/app/services/downloads.service.ts b/ui/src/app/services/downloads.service.ts
index a2ff8e9..e414921 100644
--- a/ui/src/app/services/downloads.service.ts
+++ b/ui/src/app/services/downloads.service.ts
@@ -13,6 +13,14 @@ export interface HasharrSettings {
   timeout_sec: number;
 }
 
+export interface HasharrServiceTestResponse {
+  status: string;
+  reachable: boolean;
+  valid_service_id: boolean;
+  message?: string;
+  profile?: Record<string, unknown>;
+}
+
 export interface AddDownloadPayload {
   url: string;
   downloadType: string;
@@ -243,4 +251,10 @@ export class DownloadsService {
       catchError(this.handleHTTPError)
     );
   }
+
+  testHasharrSettings(settings: Pick<HasharrSettings, 'url' | 'service_id' | 'timeout_sec'>) {
+    return this.http.post<HasharrServiceTestResponse>('hasharr-settings/test', settings).pipe(
+      catchError(this.handleHTTPError)
+    );
+  }
 }