diff --git a/src/App.js b/src/App.js
index 1cae1dd..f826b18 100644
--- a/src/App.js
+++ b/src/App.js
@@ -41,6 +41,14 @@ function makeThemes(rawCustomCardColors) {
   };
 }
 
+function parseVolume(raw) {
+  // Old versions stored "on"/"off"; new versions store a 0-100 string.
+  if (raw === "on") return 100;
+  if (raw === "off") return 0;
+  const n = Number(raw);
+  return Number.isFinite(n) ? Math.max(0, Math.min(100, Math.round(n))) : 100;
+}
+
 function makeKeyboardLayout(keyboardLayoutName, customKeyboardLayout) {
   const emptyLayout = { verticalLayout: "", horizontalLayout: "" };
   if (keyboardLayoutName !== "Custom") {
@@ -88,7 +96,12 @@ function App() {
     "orientation",
     "vertical"
   );
-  const [volume, setVolume] = useStorage("volume", "on");
+  const [rawVolume, setRawVolume] = useStorage("volume", "100");
+  const volume = parseVolume(rawVolume);
+  const setVolume = (next) =>
+    setRawVolume((prev) =>
+      String(typeof next === "function" ? next(parseVolume(prev)) : next)
+    );
   const [notifications, setNotifications] = useStorage("notifications", "on");
   const [focusMode, setFocusMode] = useStorage("focusMode", "off");
 
diff --git a/src/components/Navbar.js b/src/components/Navbar.js
index 9047617..3f2dcdf 100644
--- a/src/components/Navbar.js
+++ b/src/components/Navbar.js
@@ -1,4 +1,4 @@
-import { useContext, useEffect, useState } from "react";
+import { useContext, useEffect, useRef, useState } from "react";
 
 import AppBar from "@material-ui/core/AppBar";
 import Divider from "@material-ui/core/Divider";
@@ -6,12 +6,15 @@ import IconButton from "@material-ui/core/IconButton";
 import Link from "@material-ui/core/Link";
 import Menu from "@material-ui/core/Menu";
 import MenuItem from "@material-ui/core/MenuItem";
+import Slider from "@material-ui/core/Slider";
 import Toolbar from "@material-ui/core/Toolbar";
 import Tooltip from "@material-ui/core/Tooltip";
 import Typography from "@material-ui/core/Typography";
 import { makeStyles } from "@material-ui/core/styles";
 import EditIcon from "@material-ui/icons/Edit";
 import SettingsIcon from "@material-ui/icons/Settings";
+import VolumeOffIcon from "@material-ui/icons/VolumeOff";
+import VolumeUpIcon from "@material-ui/icons/VolumeUp";
 
 import { version } from "../config";
 import { SettingsContext, UserContext } from "../context";
@@ -44,6 +47,16 @@ const useStyles = makeStyles({
       visibility: "visible",
     },
   },
+  volumeRow: {
+    display: "flex",
+    alignItems: "center",
+    gap: 8,
+    padding: "6px 16px",
+    minWidth: 200,
+  },
+  volumeButton: {
+    padding: 4,
+  },
 });
 
 function Navbar() {
@@ -99,8 +112,15 @@ function Navbar() {
     }
   }
 
-  function handleChangeVolume() {
-    settings.setVolume((volume) => (volume === "on" ? "off" : "on"));
+  // Remembers the level to restore when unmuting via the keyboard shortcut
+  // or speaker icon, so toggling back doesn't always snap to 100%.
+  const lastVolume = useRef(settings.volume > 0 ? settings.volume : 100);
+  useEffect(() => {
+    if (settings.volume > 0) lastVolume.current = settings.volume;
+  }, [settings.volume]);
+
+  function handleToggleMute() {
+    settings.setVolume((v) => (v > 0 ? 0 : lastVolume.current));
   }
 
   function handleChangeTheme() {
@@ -124,7 +144,7 @@ function Navbar() {
     if (modifier === "Control|Shift") {
       if (key === "S") {
         event.preventDefault();
-        handleChangeVolume();
+        handleToggleMute();
       } else if (key === "F") {
         event.preventDefault();
         handleChangeFocusMode();
@@ -212,14 +232,25 @@ function Navbar() {
             </Typography>
           )}
           <Divider style={{ margin: "8px 0" }} />
-          <MenuItem
-            onClick={() => {
-              handleChangeVolume();
-              handleCloseMenu();
-            }}
-          >
-            {settings.volume === "on" ? "Mute" : "Unmute"} sound
-          </MenuItem>
+          <div className={classes.volumeRow}>
+            <Tooltip title={settings.volume > 0 ? "Mute" : "Unmute"}>
+              <IconButton
+                className={classes.volumeButton}
+                onClick={handleToggleMute}
+                aria-label={settings.volume > 0 ? "Mute sound" : "Unmute sound"}
+              >
+                {settings.volume > 0 ? <VolumeUpIcon /> : <VolumeOffIcon />}
+              </IconButton>
+            </Tooltip>
+            <Slider
+              value={settings.volume}
+              onChange={(_, v) => settings.setVolume(v)}
+              min={0}
+              max={100}
+              step={5}
+              aria-label="Sound volume"
+            />
+          </div>
           <MenuItem
             onClick={() => {
               handleChangeNotifications();
diff --git a/src/pages/GamePage.js b/src/pages/GamePage.js
index 25d1c48..d805c6a 100644
--- a/src/pages/GamePage.js
+++ b/src/pages/GamePage.js
@@ -127,9 +127,10 @@ function GamePage({ match }) {
   const [hasNextGame] = useFirebaseRef(
     spectating && game?.status === "done" ? `games/${nextGameId}/status` : null
   );
-  const [playSuccess] = useSound(foundSfx);
-  const [playFail1] = useSound(failSfx1);
-  const [playFail2] = useSound(failSfx2);
+  const soundVolume = volume / 100;
+  const [playSuccess] = useSound(foundSfx, { volume: soundVolume });
+  const [playFail1] = useSound(failSfx1, { volume: soundVolume });
+  const [playFail2] = useSound(failSfx2, { volume: soundVolume });
   const playFail = () =>
     [playFail1, playFail2][Math.floor(Math.random() * 2)]();
 
@@ -298,7 +299,7 @@ function GamePage({ match }) {
           return state.cards;
         case "set":
           handleSet(state.cards);
-          if (volume === "on") playSuccess();
+          if (volume > 0) playSuccess();
           if (notifications === "on") {
             setSnack({
               open: true,
@@ -308,7 +309,7 @@ function GamePage({ match }) {
           }
           return [];
         case "error":
-          if (volume === "on") playFail();
+          if (volume > 0) playFail();
           if (notifications === "on") {
             setSnack({
               open: true,