diff --git a/backend/src/api/analysis_api.py b/backend/src/api/analysis_api.py
index ca679f1..a99aa49 100644
--- a/backend/src/api/analysis_api.py
+++ b/backend/src/api/analysis_api.py
@@ -71,10 +71,10 @@ class InterfaceHostProtocolAnalysisResponse(BaseModel):
 @router.get("/interface-hosts", response_model=InterfaceHostAnalysisResponse)
 async def analysis_interface_hosts(
     since_minutes: Optional[int] = Query(
-        60,
+        None,
         ge=1,
         le=60 * 24 * 30,
-        description="Analyze only packets seen within the last N minutes. Set to a large value to cover more history.",
+        description="Analyze only packets seen within the last N minutes. Omit to cover all captured history.",
     ),
     limit_per_interface: int = Query(
         100,
@@ -104,10 +104,10 @@ async def analysis_interface_hosts(
 @router.get("/interface-host-protocols", response_model=InterfaceHostProtocolAnalysisResponse)
 async def analysis_interface_host_protocols(
     since_minutes: Optional[int] = Query(
-        60,
+        None,
         ge=1,
         le=60 * 24 * 30,
-        description="Analyze only packets seen within the last N minutes. Set to a large value to cover more history.",
+        description="Analyze only packets seen within the last N minutes. Omit to cover all captured history.",
     ),
     limit_per_interface: int = Query(
         50,
diff --git a/frontend/src/api/apiClient.ts b/frontend/src/api/apiClient.ts
index f0ca022..20d9981 100644
--- a/frontend/src/api/apiClient.ts
+++ b/frontend/src/api/apiClient.ts
@@ -174,12 +174,12 @@ export const clearPackets = async (): Promise<any> => {
 };
 
 export const fetchInterfaceHostAnalysis = async (
-  sinceMinutes = 60,
+  sinceMinutes: number | null = null,
   limitPerInterface = 100,
 ): Promise<InterfaceHostAnalysisResponse> => {
   const res = await api.get<InterfaceHostAnalysisResponse>('/analysis/interface-hosts', {
     params: {
-      since_minutes: sinceMinutes,
+      since_minutes: sinceMinutes ?? undefined,
       limit_per_interface: limitPerInterface,
     },
   });
@@ -187,13 +187,13 @@ export const fetchInterfaceHostAnalysis = async (
 };
 
 export const fetchInterfaceHostProtocolAnalysis = async (
-  sinceMinutes = 60,
+  sinceMinutes: number | null = null,
   limitPerInterface = 50,
   limitProtocolsPerHost = 12,
 ): Promise<InterfaceHostProtocolAnalysisResponse> => {
   const res = await api.get<InterfaceHostProtocolAnalysisResponse>('/analysis/interface-host-protocols', {
     params: {
-      since_minutes: sinceMinutes,
+      since_minutes: sinceMinutes ?? undefined,
       limit_per_interface: limitPerInterface,
       limit_protocols_per_host: limitProtocolsPerHost,
     },
diff --git a/frontend/src/pages/Analysis.tsx b/frontend/src/pages/Analysis.tsx
index 5611342..fcf98fb 100644
--- a/frontend/src/pages/Analysis.tsx
+++ b/frontend/src/pages/Analysis.tsx
@@ -544,7 +544,7 @@ function ProtocolHeatmap({ data }: { data: TopologyData }) {
 }
 
 export default function Analysis(): ReactElement {
-  const [sinceMinutes, setSinceMinutes] = useState(60);
+  const [sinceMinutes, setSinceMinutes] = useState<number | null>(null);
   const [limitPerInterface, setLimitPerInterface] = useState(50);
   const [limitProtocolsPerHost, setLimitProtocolsPerHost] = useState(12);
   const [data, setData] = useState<InterfaceHostProtocolAnalysisResponse | null>(null);
@@ -628,8 +628,14 @@ export default function Analysis(): ReactElement {
         <Space wrap size={[12, 12]}>
           <Space>
             <Text>Look back</Text>
-            <InputNumber min={1} max={60 * 24 * 30} value={sinceMinutes} onChange={(value) => setSinceMinutes(value ?? 60)} />
-            <Text type="secondary">minutes</Text>
+            <InputNumber
+              min={1}
+              max={60 * 24 * 30}
+              value={sinceMinutes}
+              placeholder="All history"
+              onChange={(value) => setSinceMinutes(value == null ? null : Number(value))}
+            />
+            <Text type="secondary">minutes, blank = all history</Text>
           </Space>
           <Space>
             <Text>Max hosts per interface</Text>