diff --git a/surfsense_web/components/layout/hooks/useSidebarResize.ts b/surfsense_web/components/layout/hooks/useSidebarResize.ts
new file mode 100644
index 000000000..887c86dce
--- /dev/null
+++ b/surfsense_web/components/layout/hooks/useSidebarResize.ts
@@ -0,0 +1,101 @@
+"use client";
+
+import { useCallback, useEffect, useRef, useState } from "react";
+
+const SIDEBAR_WIDTH_COOKIE_NAME = "sidebar_width";
+const SIDEBAR_WIDTH_COOKIE_MAX_AGE = 60 * 60 * 24 * 365; // 1 year
+
+export const SIDEBAR_MIN_WIDTH = 240;
+export const SIDEBAR_MAX_WIDTH = 480;
+
+interface UseSidebarResizeReturn {
+	sidebarWidth: number;
+	handleMouseDown: (e: React.MouseEvent) => void;
+	isDragging: boolean;
+}
+
+export function useSidebarResize(defaultWidth = SIDEBAR_MIN_WIDTH): UseSidebarResizeReturn {
+	const [sidebarWidth, setSidebarWidth] = useState(defaultWidth);
+	const [isDragging, setIsDragging] = useState(false);
+
+	const startXRef = useRef(0);
+	const startWidthRef = useRef(defaultWidth);
+
+	// Initialize from cookie on mount
+	useEffect(() => {
+		try {
+			const match = document.cookie.match(/(?:^|; )sidebar_width=([^;]+)/);
+			if (match) {
+				const parsed = Number(match[1]);
+				if (!Number.isNaN(parsed) && parsed >= SIDEBAR_MIN_WIDTH && parsed <= SIDEBAR_MAX_WIDTH) {
+					setSidebarWidth(parsed);
+				}
+			}
+		} catch {
+			// Ignore cookie read errors
+		}
+	}, []);
+
+	// Persist width to cookie
+	const persistWidth = useCallback((width: number) => {
+		try {
+			document.cookie = `${SIDEBAR_WIDTH_COOKIE_NAME}=${width}; path=/; max-age=${SIDEBAR_WIDTH_COOKIE_MAX_AGE}`;
+		} catch {
+			// Ignore cookie write errors
+		}
+	}, []);
+
+	const handleMouseDown = useCallback(
+		(e: React.MouseEvent) => {
+			e.preventDefault();
+			startXRef.current = e.clientX;
+			startWidthRef.current = sidebarWidth;
+			setIsDragging(true);
+
+			document.body.style.cursor = "col-resize";
+			document.body.style.userSelect = "none";
+		},
+		[sidebarWidth]
+	);
+
+	useEffect(() => {
+		if (!isDragging) return;
+
+		const handleMouseMove = (e: MouseEvent) => {
+			const delta = e.clientX - startXRef.current;
+			const newWidth = Math.min(
+				SIDEBAR_MAX_WIDTH,
+				Math.max(SIDEBAR_MIN_WIDTH, startWidthRef.current + delta)
+			);
+			setSidebarWidth(newWidth);
+		};
+
+		const handleMouseUp = () => {
+			setIsDragging(false);
+			document.body.style.cursor = "";
+			document.body.style.userSelect = "";
+
+			// Persist the final width
+			setSidebarWidth((currentWidth) => {
+				persistWidth(currentWidth);
+				return currentWidth;
+			});
+		};
+
+		document.addEventListener("mousemove", handleMouseMove);
+		document.addEventListener("mouseup", handleMouseUp);
+
+		return () => {
+			document.removeEventListener("mousemove", handleMouseMove);
+			document.removeEventListener("mouseup", handleMouseUp);
+			document.body.style.cursor = "";
+			document.body.style.userSelect = "";
+		};
+	}, [isDragging, persistWidth]);
+
+	return {
+		sidebarWidth,
+		handleMouseDown,
+		isDragging,
+	};
+}
diff --git a/surfsense_web/components/layout/ui/sidebar/Sidebar.tsx b/surfsense_web/components/layout/ui/sidebar/Sidebar.tsx
index 883fa5890..6b0c9fe7a 100644
--- a/surfsense_web/components/layout/ui/sidebar/Sidebar.tsx
+++ b/surfsense_web/components/layout/ui/sidebar/Sidebar.tsx
@@ -7,6 +7,7 @@ import { Skeleton } from "@/components/ui/skeleton";
 import { Tooltip, TooltipContent, TooltipTrigger } from "@/components/ui/tooltip";
 import { cn } from "@/lib/utils";
 import type { ChatItem, NavItem, PageUsage, SearchSpace, User } from "../../types/layout.types";
+import { useSidebarResize } from "../../hooks/useSidebarResize";
 import { ChatListItem } from "./ChatListItem";
 import { NavSection } from "./NavSection";
 import { PageUsageDisplay } from "./PageUsageDisplay";
@@ -82,15 +83,25 @@ export function Sidebar({
 	disableTooltips = false,
 }: SidebarProps) {
 	const t = useTranslations("sidebar");
+	const { sidebarWidth, handleMouseDown, isDragging } = useSidebarResize();
 
 	return (
 		<div
 			className={cn(
-				"flex h-full flex-col bg-sidebar text-sidebar-foreground transition-all duration-200 overflow-hidden",
-				isCollapsed ? "w-[60px]" : "w-[240px]",
+				"relative flex h-full flex-col bg-sidebar text-sidebar-foreground overflow-hidden",
+				isCollapsed ? "w-[60px] transition-all duration-200" : "",
+				!isCollapsed && !isDragging ? "transition-all duration-200" : "",
 				className
 			)}
+			style={!isCollapsed ? { width: sidebarWidth } : undefined}
 		>
+			{/* Resize handle on right border */}
+			{!isCollapsed && (
+				<div
+					onMouseDown={handleMouseDown}
+					className="absolute right-0 top-0 h-full w-1 cursor-col-resize hover:bg-border active:bg-border z-10"
+				/>
+			)}
 			{/* Header - search space name or collapse button when collapsed */}
 			{isCollapsed ? (
 				<div className="flex h-14 shrink-0 items-center justify-center border-b">