diff --git a/client/src/contexts/DateRangeContext.tsx b/client/src/contexts/DateRangeContext.tsx
index 29c4013..7efa51e 100644
--- a/client/src/contexts/DateRangeContext.tsx
+++ b/client/src/contexts/DateRangeContext.tsx
@@ -59,12 +59,39 @@ interface DateRangeContextValue {
   until: string | undefined;
 }
 
+const VALID_RANGES = ['1w', '2w', '1m', '3m', '6m', '1y', 'all', 'custom'] as const;
+
+/** Read initial date range from URL search params (synchronous, for useState init). */
+function getInitialRange(): { range: TimeRange; since: string; until: string } {
+  if (typeof window === 'undefined') {
+    const def = getDateRange('1w');
+    return { range: '1w', since: def.since!.slice(0, 10), until: def.until!.slice(0, 10) };
+  }
+  const params = new URLSearchParams(window.location.search);
+  const range = params.get('range') as TimeRange | null;
+  if (range && (VALID_RANGES as readonly string[]).includes(range)) {
+    if (range === 'custom') {
+      const since = params.get('since') ?? getDateRange('1w').since!.slice(0, 10);
+      const until = params.get('until') ?? getDateRange('1w').until!.slice(0, 10);
+      return { range: 'custom', since, until };
+    }
+    if (range === 'all') {
+      return { range: 'all', since: '', until: '' };
+    }
+    const computed = getDateRange(range);
+    return { range, since: computed.since!.slice(0, 10), until: computed.until!.slice(0, 10) };
+  }
+  const def = getDateRange('1w');
+  return { range: '1w', since: def.since!.slice(0, 10), until: def.until!.slice(0, 10) };
+}
+
 const DateRangeContext = createContext<DateRangeContextValue | null>(null);
 
 export function DateRangeProvider({ children }: { children: ReactNode }) {
-  const [timeRange, setTimeRange] = useState<TimeRange>('1w');
-  const [customSince, setCustomSince] = useState<string>(() => getDateRange('1w').since!.slice(0, 10));
-  const [customUntil, setCustomUntil] = useState<string>(() => getDateRange('1w').until!.slice(0, 10));
+  const initial = getInitialRange();
+  const [timeRange, setTimeRange] = useState<TimeRange>(initial.range);
+  const [customSince, setCustomSince] = useState<string>(initial.since);
+  const [customUntil, setCustomUntil] = useState<string>(initial.until);
 
   // Sync date inputs when switching to a preset
   useEffect(() => {
diff --git a/client/src/hooks/useUrlParams.ts b/client/src/hooks/useUrlParams.ts
new file mode 100644
index 0000000..6cf5291
--- /dev/null
+++ b/client/src/hooks/useUrlParams.ts
@@ -0,0 +1,100 @@
+import { useCallback, useEffect, useRef } from 'react';
+import { useSearchParams } from 'react-router';
+import { useDateRange } from '../contexts/DateRangeContext.js';
+import type { TimeRange } from '../contexts/DateRangeContext.js';
+
+/**
+ * Returns a stable `updateParams` function that merges specific search params
+ * into the current URL without replacing unrelated params.
+ * Pass `null` as a value to delete a param.
+ */
+export function useUpdateSearchParams() {
+  const [searchParams, setSearchParams] = useSearchParams();
+  const update = useCallback(
+    (updates: Record<string, string | null>) => {
+      setSearchParams(
+        (prev) => {
+          const next = new URLSearchParams(prev);
+          for (const [key, value] of Object.entries(updates)) {
+            if (value === null || value === '') next.delete(key);
+            else next.set(key, value);
+          }
+          return next;
+        },
+        { replace: true },
+      );
+    },
+    [setSearchParams],
+  );
+  return { searchParams, updateParams: update };
+}
+
+const VALID_RANGES: TimeRange[] = ['1w', '2w', '1m', '3m', '6m', '1y', 'all', 'custom'];
+
+/**
+ * Syncs the DateRangeContext with URL search params (`range`, `since`, `until`).
+ * Call this in each page that renders a DateRangePicker.
+ *
+ * - On mount: reads URL params → sets context (if present).
+ * - On context change: writes URL params (skips the echo-back after URL→context init).
+ * - Default value (`1w`) is omitted from the URL to keep links clean.
+ */
+export function useDateRangeParams() {
+  const {
+    timeRange,
+    setTimeRange,
+    customSince,
+    setCustomSince,
+    customUntil,
+    setCustomUntil,
+  } = useDateRange();
+  const { updateParams } = useUpdateSearchParams();
+
+  // mountedRef: set to true after the init effect runs (both effects share this render cycle).
+  const mountedRef = useRef(false);
+  // skipUrlWriteRef: set when we triggered a context change from URL so we skip echoing it back.
+  const skipUrlWriteRef = useRef(false);
+
+  // Effect 1: URL → context (mount only)
+  useEffect(() => {
+    const params = new URLSearchParams(window.location.search);
+    const range = params.get('range') as TimeRange | null;
+    if (range && VALID_RANGES.includes(range)) {
+      skipUrlWriteRef.current = true;
+      setTimeRange(range);
+      if (range === 'custom') {
+        const since = params.get('since');
+        const until = params.get('until');
+        if (since) setCustomSince(since);
+        if (until) setCustomUntil(until);
+      }
+    }
+    mountedRef.current = true;
+  }, []); // eslint-disable-line react-hooks/exhaustive-deps
+
+  // Effect 2: context → URL (runs after every context change)
+  useEffect(() => {
+    if (!mountedRef.current) return;
+    // Skip the write triggered by our own URL→context init to avoid an echo loop.
+    if (skipUrlWriteRef.current) {
+      skipUrlWriteRef.current = false;
+      return;
+    }
+    const updates: Record<string, string | null> = {};
+    if (timeRange === '1w') {
+      // Default — omit from URL to keep it clean
+      updates.range = null;
+      updates.since = null;
+      updates.until = null;
+    } else if (timeRange === 'custom') {
+      updates.range = 'custom';
+      updates.since = customSince || null;
+      updates.until = customUntil || null;
+    } else {
+      updates.range = timeRange;
+      updates.since = null;
+      updates.until = null;
+    }
+    updateParams(updates);
+  }, [timeRange, customSince, customUntil]); // eslint-disable-line react-hooks/exhaustive-deps
+}
diff --git a/client/src/pages/AppLayout.tsx b/client/src/pages/AppLayout.tsx
index 5c76aed..28d81f2 100644
--- a/client/src/pages/AppLayout.tsx
+++ b/client/src/pages/AppLayout.tsx
@@ -15,7 +15,11 @@ export default function AppLayout() {
   const params = useParams();
   const location = useLocation();
 
-  const [selectedOwner, setSelectedOwner] = useState<string | null>(null);
+  const [selectedOwner, setSelectedOwner] = useState<string | null>(() => {
+    // Initialize from URL params — if the repo owner differs from the logged-in user,
+    // set selectedOwner to match so the correct org's repos are loaded
+    return params.owner ?? null;
+  });
   const [showOrgDropdown, setShowOrgDropdown] = useState(false);
   const [showRepoDropdown, setShowRepoDropdown] = useState(false);
   const [searchQuery, setSearchQuery] = useState('');
@@ -36,6 +40,15 @@ export default function AppLayout() {
     }
   }, [isAuthenticated, isLoading, navigate]);
 
+  // Sync org dropdown with URL owner param (for deep linking)
+  useEffect(() => {
+    if (params.owner && params.owner !== selectedOwner) {
+      // If URL owner matches logged-in user, treat as Personal (null works too, but
+      // setting it explicitly ensures the repos list fetches for the right owner)
+      setSelectedOwner(params.owner);
+    }
+  }, [params.owner]); // eslint-disable-line react-hooks/exhaustive-deps
+
   // Close dropdowns on outside click
   useEffect(() => {
     function handleClick(e: MouseEvent) {
@@ -78,7 +91,15 @@ export default function AppLayout() {
     setSearchQuery('');
     const suffixes = ['/network', '/pulls', '/branches', '/settings', '/code-frequency'];
     const currentSuffix = suffixes.find((s) => location.pathname.endsWith(s)) ?? '';
-    void navigate(`/app/repo/${repo.owner.login}/${repo.name}${currentSuffix}`);
+    // Preserve date-range params when switching repos; drop repo-specific params (branches, etc.)
+    const currentParams = new URLSearchParams(location.search);
+    const newParams = new URLSearchParams();
+    for (const key of ['range', 'since', 'until']) {
+      const val = currentParams.get(key);
+      if (val) newParams.set(key, val);
+    }
+    const qs = newParams.toString() ? `?${newParams.toString()}` : '';
+    void navigate(`/app/repo/${repo.owner.login}/${repo.name}${currentSuffix}${qs}`);
   }
 
   const isPersonal = selectedOwner === null || selectedOwner === user?.login;
@@ -564,7 +585,7 @@ export default function AppLayout() {
               label: 'Commit Graph',
               active: isOnGraphPage,
               href: currentRepo
-                ? `/app/repo/${currentRepo.owner.login}/${currentRepo.name}`
+                ? `/app/repo/${currentRepo.owner.login}/${currentRepo.name}${location.search}`
                 : '/app',
             },
             {
@@ -572,7 +593,7 @@ export default function AppLayout() {
               label: 'Network Graph',
               active: isOnNetworkPage,
               href: currentRepo
-                ? `/app/repo/${currentRepo.owner.login}/${currentRepo.name}/network`
+                ? `/app/repo/${currentRepo.owner.login}/${currentRepo.name}/network${location.search}`
                 : '/app',
             },
             {
@@ -580,7 +601,7 @@ export default function AppLayout() {
               label: 'Pull Requests',
               active: isOnPullsPage,
               href: currentRepo
-                ? `/app/repo/${currentRepo.owner.login}/${currentRepo.name}/pulls`
+                ? `/app/repo/${currentRepo.owner.login}/${currentRepo.name}/pulls${location.search}`
                 : '/app',
             },
             {
@@ -588,7 +609,7 @@ export default function AppLayout() {
               label: 'Branches',
               active: isOnBranchesPage,
               href: currentRepo
-                ? `/app/repo/${currentRepo.owner.login}/${currentRepo.name}/branches`
+                ? `/app/repo/${currentRepo.owner.login}/${currentRepo.name}/branches${location.search}`
                 : '/app',
             },
             {
@@ -596,7 +617,7 @@ export default function AppLayout() {
               label: 'Code Frequency',
               active: isOnCodeFrequencyPage,
               href: currentRepo
-                ? `/app/repo/${currentRepo.owner.login}/${currentRepo.name}/code-frequency`
+                ? `/app/repo/${currentRepo.owner.login}/${currentRepo.name}/code-frequency${location.search}`
                 : '/app',
             },
             {
@@ -604,7 +625,7 @@ export default function AppLayout() {
               label: 'Settings',
               active: isOnSettingsPage,
               href: currentRepo
-                ? `/app/repo/${currentRepo.owner.login}/${currentRepo.name}/settings`
+                ? `/app/repo/${currentRepo.owner.login}/${currentRepo.name}/settings${location.search}`
                 : '/app',
             },
           ].map((item) => (
diff --git a/client/src/pages/BranchesPage.tsx b/client/src/pages/BranchesPage.tsx
index f1b4d6c..5feb278 100644
--- a/client/src/pages/BranchesPage.tsx
+++ b/client/src/pages/BranchesPage.tsx
@@ -1,8 +1,9 @@
-import { useState } from 'react';
+import { useState, useEffect } from 'react';
 import { useParams, useNavigate } from 'react-router';
 import { useQuery } from '@tanstack/react-query';
 import { api } from '../lib/api.js';
 import type { BranchInfo, TagInfo } from '../lib/api.js';
+import { useUpdateSearchParams } from '../hooks/useUrlParams.js';
 
 type SortMode = 'updated' | 'name' | 'ahead';
 type TabMode = 'branches' | 'tags';
@@ -300,9 +301,31 @@ function TagRow({ tag }: { tag: TagInfo }) {
 export default function BranchesPage() {
   const { owner, repo } = useParams<{ owner: string; repo: string }>();
   const navigate = useNavigate();
-  const [sortMode, setSortMode] = useState<SortMode>('updated');
-  const [activeTab, setActiveTab] = useState<TabMode>('branches');
-  const [searchQuery, setSearchQuery] = useState('');
+
+  const [sortMode, setSortMode] = useState<SortMode>(() => {
+    const s = new URLSearchParams(window.location.search).get('sort');
+    if (s === 'updated' || s === 'name' || s === 'ahead') return s;
+    return 'updated';
+  });
+  const [activeTab, setActiveTab] = useState<TabMode>(() => {
+    const t = new URLSearchParams(window.location.search).get('tab');
+    if (t === 'branches' || t === 'tags') return t;
+    return 'branches';
+  });
+  const [searchQuery, setSearchQuery] = useState(
+    () => new URLSearchParams(window.location.search).get('q') ?? '',
+  );
+
+  const { updateParams } = useUpdateSearchParams();
+
+  // Sync sort/tab/q to URL on change
+  useEffect(() => {
+    updateParams({
+      sort: sortMode === 'updated' ? null : sortMode,
+      tab: activeTab === 'branches' ? null : activeTab,
+      q: searchQuery || null,
+    });
+  }, [sortMode, activeTab, searchQuery]); // eslint-disable-line react-hooks/exhaustive-deps
 
   const { data: branches, isLoading: branchesLoading, error: branchesError } = useQuery({
     queryKey: ['branches', owner, repo],
diff --git a/client/src/pages/CodeFrequencyPage.tsx b/client/src/pages/CodeFrequencyPage.tsx
index 248f8c2..96ffeaa 100644
--- a/client/src/pages/CodeFrequencyPage.tsx
+++ b/client/src/pages/CodeFrequencyPage.tsx
@@ -7,6 +7,7 @@ import TopFilesTable from '../components/TopFilesTable.js';
 import ContributorsChart from '../components/ContributorsChart.js';
 import { useDateRange } from '../contexts/DateRangeContext.js';
 import DateRangePicker from '../components/DateRangePicker.js';
+import { useUpdateSearchParams, useDateRangeParams } from '../hooks/useUrlParams.js';
 
 type Tab = 'timeseries' | 'treemap' | 'topfiles' | 'contributors';
 
@@ -20,10 +21,27 @@ interface StreamState {
 
 export default function CodeFrequencyPage() {
   const { owner, repo } = useParams<{ owner: string; repo: string }>();
-  const [tab, setTab] = useState<Tab>('timeseries');
-  const [pathFilter, setPathFilter] = useState('');
+  const [tab, setTab] = useState<Tab>(() => {
+    const t = new URLSearchParams(window.location.search).get('tab');
+    if (t === 'timeseries' || t === 'treemap' || t === 'topfiles' || t === 'contributors') return t;
+    return 'timeseries';
+  });
+  const [pathFilter, setPathFilter] = useState(
+    () => new URLSearchParams(window.location.search).get('path') ?? '',
+  );
   const [loadKey, setLoadKey] = useState(0);
 
+  const { updateParams } = useUpdateSearchParams();
+  useDateRangeParams();
+
+  // Sync tab/path to URL
+  useEffect(() => {
+    updateParams({
+      tab: tab === 'timeseries' ? null : tab,
+      path: pathFilter || null,
+    });
+  }, [tab, pathFilter]); // eslint-disable-line react-hooks/exhaustive-deps
+
   const { since, until } = useDateRange();
 
   const [streamState, setStreamState] = useState<StreamState>({
diff --git a/client/src/pages/GraphPage.tsx b/client/src/pages/GraphPage.tsx
index 388d2c7..3eb383e 100644
--- a/client/src/pages/GraphPage.tsx
+++ b/client/src/pages/GraphPage.tsx
@@ -2,6 +2,7 @@ import { useState, useEffect } from 'react';
 import { useParams } from 'react-router';
 import { useQuery } from '@tanstack/react-query';
 import { useMultiBranchCommits, useCommitDetail } from '../hooks/useCommits.js';
+import { useUpdateSearchParams, useDateRangeParams } from '../hooks/useUrlParams.js';
 import { api } from '../lib/api.js';
 import GraphVisualization from '../components/GraphVisualization.js';
 import CommitDetail from '../components/CommitDetail.js';
@@ -11,9 +12,17 @@ import DateRangePicker from '../components/DateRangePicker.js';
 
 export default function GraphPage() {
   const { owner, repo } = useParams<{ owner: string; repo: string }>();
-  const [selectedBranches, setSelectedBranches] = useState<string[]>([]);
+  const [selectedBranches, setSelectedBranches] = useState<string[]>(() => {
+    const params = new URLSearchParams(window.location.search);
+    const param = params.get('branches');
+    if (!param) return [];
+    return param.split(',').map(decodeURIComponent).filter(Boolean);
+  });
   const [selectedOid, setSelectedOid] = useState<string | null>(null);
 
+  const { updateParams } = useUpdateSearchParams();
+  useDateRangeParams();
+
   const { since, until } = useDateRange();
 
   const { data: overview, isLoading: overviewLoading } = useQuery({
@@ -24,11 +33,12 @@ export default function GraphPage() {
 
   const defaultBranch = overview?.defaultBranchRef?.name ?? 'main';
 
-  // Reset branches + selection when repo changes
+  // Reset branches + selection when repo changes; clear URL branches param
   useEffect(() => {
     setSelectedBranches([]);
     setSelectedOid(null);
-  }, [owner, repo]);
+    updateParams({ branches: null });
+  }, [owner, repo]); // eslint-disable-line react-hooks/exhaustive-deps
 
   // Once overview loads, seed selectedBranches with just the default branch
   useEffect(() => {
@@ -119,6 +129,10 @@ export default function GraphPage() {
             onChange={(next) => {
               setSelectedBranches(next);
               setSelectedOid(null);
+              const isDefaultOnly = next.length === 1 && next[0] === defaultBranch;
+              updateParams({
+                branches: (isDefaultOnly || next.length === 0) ? null : next.map(encodeURIComponent).join(','),
+              });
             }}
             disabled={overviewLoading}
           />
diff --git a/client/src/pages/NetworkPage.tsx b/client/src/pages/NetworkPage.tsx
index 89486e3..2d56153 100644
--- a/client/src/pages/NetworkPage.tsx
+++ b/client/src/pages/NetworkPage.tsx
@@ -2,6 +2,7 @@ import { useState, useEffect, useMemo } from 'react';
 import { useParams } from 'react-router';
 import { useQuery } from '@tanstack/react-query';
 import { useMultiBranchCommits, useCommitDetail } from '../hooks/useCommits.js';
+import { useUpdateSearchParams, useDateRangeParams } from '../hooks/useUrlParams.js';
 import { api } from '../lib/api.js';
 import type { CommitNode } from '../lib/api.js';
 import NetworkGraphVisualization from '../components/NetworkGraphVisualization.js';
@@ -12,9 +13,17 @@ import DateRangePicker from '../components/DateRangePicker.js';
 
 export default function NetworkPage() {
   const { owner, repo } = useParams<{ owner: string; repo: string }>();
-  const [selectedBranches, setSelectedBranches] = useState<string[]>([]);
+  const [selectedBranches, setSelectedBranches] = useState<string[]>(() => {
+    const params = new URLSearchParams(window.location.search);
+    const param = params.get('branches');
+    if (!param) return [];
+    return param.split(',').map(decodeURIComponent).filter(Boolean);
+  });
   const [selectedOid, setSelectedOid] = useState<string | null>(null);
 
+  const { updateParams } = useUpdateSearchParams();
+  useDateRangeParams();
+
   const { since, until } = useDateRange();
 
   const { data: overview, isLoading: overviewLoading } = useQuery({
@@ -29,7 +38,8 @@ export default function NetworkPage() {
   useEffect(() => {
     setSelectedBranches([]);
     setSelectedOid(null);
-  }, [owner, repo]);
+    updateParams({ branches: null });
+  }, [owner, repo]); // eslint-disable-line react-hooks/exhaustive-deps
 
   // Auto-select ALL branches once overview loads
   useEffect(() => {
@@ -218,6 +228,14 @@ export default function NetworkPage() {
             onChange={(next) => {
               setSelectedBranches(next);
               setSelectedOid(null);
+              // Omit param when all branches are selected (that's the default for network view)
+              const allSelected =
+                allBranchNames.length > 0 &&
+                next.length === allBranchNames.length &&
+                allBranchNames.every((b) => next.includes(b));
+              updateParams({
+                branches: (allSelected || next.length === 0) ? null : next.map(encodeURIComponent).join(','),
+              });
             }}
             disabled={overviewLoading}
           />
diff --git a/client/src/pages/PullRequestsPage.tsx b/client/src/pages/PullRequestsPage.tsx
index 18efbf6..692beda 100644
--- a/client/src/pages/PullRequestsPage.tsx
+++ b/client/src/pages/PullRequestsPage.tsx
@@ -1,10 +1,11 @@
-import { useState, useRef } from 'react';
+import { useState, useRef, useEffect } from 'react';
 import { useParams } from 'react-router';
 import { useQuery } from '@tanstack/react-query';
 import { api } from '../lib/api.js';
 import type { PullRequest } from '../lib/api.js';
 import { useDateRange } from '../contexts/DateRangeContext.js';
 import DateRangePicker from '../components/DateRangePicker.js';
+import { useUpdateSearchParams, useDateRangeParams } from '../hooks/useUrlParams.js';
 
 type PRState = 'ALL' | 'OPEN' | 'CLOSED' | 'MERGED';
 type SortMode = 'newest' | 'oldest' | 'most-comments' | 'most-reviews';
@@ -544,10 +545,36 @@ function PRRow({ pr }: { pr: PullRequest }) {
 
 export default function PullRequestsPage() {
   const { owner, repo } = useParams<{ owner: string; repo: string }>();
-  const [activeState, setActiveState] = useState<PRState>('OPEN');
-  const [sortMode, setSortMode] = useState<SortMode>('newest');
-  const [authorFilter, setAuthorFilter] = useState('');
-  const [reviewerFilter, setReviewerFilter] = useState('');
+
+  const [activeState, setActiveState] = useState<PRState>(() => {
+    const s = new URLSearchParams(window.location.search).get('state');
+    if (s === 'ALL' || s === 'OPEN' || s === 'CLOSED' || s === 'MERGED') return s;
+    return 'OPEN';
+  });
+  const [sortMode, setSortMode] = useState<SortMode>(() => {
+    const s = new URLSearchParams(window.location.search).get('sort');
+    if (s === 'newest' || s === 'oldest' || s === 'most-comments' || s === 'most-reviews') return s;
+    return 'newest';
+  });
+  const [authorFilter, setAuthorFilter] = useState(
+    () => new URLSearchParams(window.location.search).get('author') ?? '',
+  );
+  const [reviewerFilter, setReviewerFilter] = useState(
+    () => new URLSearchParams(window.location.search).get('reviewer') ?? '',
+  );
+
+  const { updateParams } = useUpdateSearchParams();
+  useDateRangeParams();
+
+  // Sync state/sort/author/reviewer to URL on change
+  useEffect(() => {
+    updateParams({
+      state: activeState === 'OPEN' ? null : activeState,
+      sort: sortMode === 'newest' ? null : sortMode,
+      author: authorFilter || null,
+      reviewer: reviewerFilter || null,
+    });
+  }, [activeState, sortMode, authorFilter, reviewerFilter]); // eslint-disable-line react-hooks/exhaustive-deps
 
   const { since, until } = useDateRange();