diff --git a/backend/app/core/config.py b/backend/app/core/config.py
index 455425f..17adeca 100644
--- a/backend/app/core/config.py
+++ b/backend/app/core/config.py
@@ -24,7 +24,7 @@ class Settings(BaseSettings):
     # Site inspection
     SITE_MAX_PAGES: int = 500
     SITE_MAX_DEPTH: int = 2
-    SITE_CONCURRENCY: int = 2
+    SITE_CONCURRENCY: int = 4
 
     # Application
     PROJECT_NAME: str = "Web Inspector API"
diff --git a/backend/app/models/site_schemas.py b/backend/app/models/site_schemas.py
index 10a2a09..cc5b9fd 100644
--- a/backend/app/models/site_schemas.py
+++ b/backend/app/models/site_schemas.py
@@ -30,6 +30,7 @@ class StartSiteInspectionRequest(BaseModel):
     url: HttpUrl
     max_pages: int = Field(default=20, ge=0, le=500, description="최대 크롤링 페이지 수 (0=무제한)")
     max_depth: int = Field(default=2, ge=1, le=3, description="최대 크롤링 깊이")
+    concurrency: int = Field(default=4, ge=1, le=8, description="동시 검사 수")
 
 
 class InspectPageRequest(BaseModel):
@@ -67,6 +68,7 @@ class SiteInspectionConfig(BaseModel):
     """사이트 검사 설정."""
     max_pages: int = 20
     max_depth: int = 2
+    concurrency: int = 4
 
 
 # --- Response Models ---
diff --git a/backend/app/routers/site_inspections.py b/backend/app/routers/site_inspections.py
index 76a31cf..f5391dd 100644
--- a/backend/app/routers/site_inspections.py
+++ b/backend/app/routers/site_inspections.py
@@ -66,6 +66,7 @@ async def start_site_inspection(request: StartSiteInspectionRequest):
             url=url,
             max_pages=request.max_pages,
             max_depth=request.max_depth,
+            concurrency=request.concurrency,
         )
     except httpx.HTTPStatusError as e:
         raise HTTPException(
diff --git a/backend/app/services/site_inspection_service.py b/backend/app/services/site_inspection_service.py
index 7a1c5b1..149e918 100644
--- a/backend/app/services/site_inspection_service.py
+++ b/backend/app/services/site_inspection_service.py
@@ -49,6 +49,7 @@ class SiteInspectionService:
         url: str,
         max_pages: int = 20,
         max_depth: int = 2,
+        concurrency: int = 4,
     ) -> str:
         """
         Start a site-wide inspection.
@@ -65,6 +66,7 @@ class SiteInspectionService:
         if max_pages > 0:
             max_pages = min(max_pages, settings.SITE_MAX_PAGES)
         max_depth = min(max_depth, settings.SITE_MAX_DEPTH)
+        concurrency = min(concurrency, settings.SITE_CONCURRENCY)
 
         site_inspection_id = str(uuid.uuid4())
         parsed = urlparse(url)
@@ -81,6 +83,7 @@ class SiteInspectionService:
             "config": {
                 "max_pages": max_pages,
                 "max_depth": max_depth,
+                "concurrency": concurrency,
             },
             "discovered_pages": [],
             "aggregate_scores": None,
@@ -88,13 +91,13 @@ class SiteInspectionService:
         await self.db.site_inspections.insert_one(doc)
 
         logger.info(
-            "Site inspection started: id=%s, url=%s, max_pages=%d, max_depth=%d",
-            site_inspection_id, url, max_pages, max_depth,
+            "Site inspection started: id=%s, url=%s, max_pages=%d, max_depth=%d, concurrency=%d",
+            site_inspection_id, url, max_pages, max_depth, concurrency,
         )
 
         # Launch background task
         asyncio.create_task(
-            self._crawl_and_inspect(site_inspection_id, url, max_pages, max_depth)
+            self._crawl_and_inspect(site_inspection_id, url, max_pages, max_depth, concurrency)
         )
 
         return site_inspection_id
@@ -268,6 +271,7 @@ class SiteInspectionService:
         url: str,
         max_pages: int,
         max_depth: int,
+        concurrency: int = 4,
     ) -> None:
         """
         Background task that runs in two phases:
@@ -349,8 +353,7 @@ class SiteInspectionService:
             # ==============================
             logger.info("Phase 2 (inspection) started: %s", site_inspection_id)
 
-            settings = get_settings()
-            semaphore = asyncio.Semaphore(settings.SITE_CONCURRENCY)
+            semaphore = asyncio.Semaphore(concurrency)
 
             tasks = [
                 self._inspect_page_with_semaphore(
diff --git a/frontend/src/components/inspection/UrlInputForm.tsx b/frontend/src/components/inspection/UrlInputForm.tsx
index 0a44f57..dded516 100644
--- a/frontend/src/components/inspection/UrlInputForm.tsx
+++ b/frontend/src/components/inspection/UrlInputForm.tsx
@@ -18,6 +18,9 @@ const MAX_PAGES_OPTIONS = [10, 20, 50, 0] as const;
 /** 크롤링 깊이 옵션 */
 const MAX_DEPTH_OPTIONS = [1, 2, 3] as const;
 
+/** 동시 검사 수 옵션 */
+const CONCURRENCY_OPTIONS = [1, 2, 4, 8] as const;
+
 export function UrlInputForm() {
   const [url, setUrl] = useState("");
   const [error, setError] = useState<string | null>(null);
@@ -26,6 +29,7 @@ export function UrlInputForm() {
   const [showSiteOptions, setShowSiteOptions] = useState(false);
   const [maxPages, setMaxPages] = useState<number>(20);
   const [maxDepth, setMaxDepth] = useState<number>(2);
+  const [concurrency, setConcurrency] = useState<number>(4);
   const router = useRouter();
   const { setInspection } = useInspectionStore();
   const { setSiteInspection } = useSiteInspectionStore();
@@ -101,7 +105,8 @@ export function UrlInputForm() {
       const response = await api.startSiteInspection(
         trimmedUrl,
         maxPages,
-        maxDepth
+        maxDepth,
+        concurrency
       );
       setSiteInspection(response.site_inspection_id, trimmedUrl);
       router.push(
@@ -225,7 +230,7 @@ export function UrlInputForm() {
                     </div>
 
                     {/* 크롤링 깊이 */}
-                    <div className="mb-4">
+                    <div className="mb-3">
                       <label className="text-xs text-muted-foreground mb-1.5 block">
                         크롤링 깊이
                       </label>
@@ -250,6 +255,32 @@ export function UrlInputForm() {
                       </div>
                     </div>
 
+                    {/* 동시 검사 수 */}
+                    <div className="mb-4">
+                      <label className="text-xs text-muted-foreground mb-1.5 block">
+                        동시 검사 수
+                      </label>
+                      <div className="flex gap-2">
+                        {CONCURRENCY_OPTIONS.map((option) => (
+                          <Button
+                            key={option}
+                            type="button"
+                            variant={
+                              concurrency === option ? "default" : "outline"
+                            }
+                            size="sm"
+                            className={cn(
+                              "flex-1",
+                              concurrency === option && "pointer-events-none"
+                            )}
+                            onClick={() => setConcurrency(option)}
+                          >
+                            {option}
+                          </Button>
+                        ))}
+                      </div>
+                    </div>
+
                     {/* 사이트 검사 시작 버튼 */}
                     <Button
                       type="button"
diff --git a/frontend/src/lib/api.ts b/frontend/src/lib/api.ts
index 5551289..0313070 100644
--- a/frontend/src/lib/api.ts
+++ b/frontend/src/lib/api.ts
@@ -157,7 +157,8 @@ class ApiClient {
   async startSiteInspection(
     url: string,
     maxPages?: number,
-    maxDepth?: number
+    maxDepth?: number,
+    concurrency?: number
   ): Promise<StartSiteInspectionResponse> {
     return this.request("/api/site-inspections", {
       method: "POST",
@@ -165,6 +166,7 @@ class ApiClient {
         url,
         max_pages: maxPages,
         max_depth: maxDepth,
+        concurrency: concurrency,
       }),
     });
   }