diff --git a/studio/setup.sh b/studio/setup.sh
index 749c585a26..13d654cdd6 100755
--- a/studio/setup.sh
+++ b/studio/setup.sh
@@ -492,7 +492,18 @@ _clear_webview_caches() {
             )
             ;;
         Linux)
-            _wvc_paths=("${XDG_CACHE_HOME:-$HOME/.cache}/$_wvc_bid")
+            # wry keys the WebKitGTK base-cache dir to the app DATA dir (same
+            # as base-data), so cache subdirs also live under
+            # ~/.local/share/<bid>. Clear only the cache-typed subdirs there;
+            # sibling localstorage/, indexeddb/, and cookies stay.
+            _wvc_data="${XDG_DATA_HOME:-$HOME/.local/share}/$_wvc_bid"
+            _wvc_paths=(
+                "${XDG_CACHE_HOME:-$HOME/.cache}/$_wvc_bid"
+                "$_wvc_data/WebKitCache"
+                "$_wvc_data/CacheStorage"
+                "$_wvc_data/serviceworkers"
+                "$_wvc_data/ServiceWorkers"
+            )
             ;;
         *) return 0 ;;
     esac
diff --git a/studio/src-tauri/src/main.rs b/studio/src-tauri/src/main.rs
index 405b390177..e422124f0c 100644
--- a/studio/src-tauri/src/main.rs
+++ b/studio/src-tauri/src/main.rs
@@ -161,6 +161,64 @@ fn setup_tray(app: &tauri::App) -> Result<(), Box<dyn std::error::Error>> {
     Ok(())
 }
 
+// Clear WebView caches before the webview initializes. An in-app update runs
+// setup.sh/setup.ps1 while the old WebView still holds these files (its clear
+// silently fails), so without this a relaunch can serve the previous frontend
+// from cache. Cache-only paths; LocalStorage, IndexedDB, cookies, and app
+// data are kept. Mirrors setup.sh _clear_webview_caches / setup.ps1.
+fn clear_webview_caches(bundle_id: &str) {
+    use std::path::PathBuf;
+    let mut paths: Vec<PathBuf> = Vec::new();
+    #[cfg(target_os = "windows")]
+    if let Ok(local) = std::env::var("LOCALAPPDATA") {
+        if !local.is_empty() {
+            let profile = PathBuf::from(local)
+                .join(bundle_id)
+                .join("EBWebView")
+                .join("Default");
+            for sub in ["Cache", "Code Cache", "GPUCache", "Service Worker"] {
+                paths.push(profile.join(sub));
+            }
+        }
+    }
+    #[cfg(target_os = "macos")]
+    if let Ok(home) = std::env::var("HOME") {
+        if !home.is_empty() {
+            let home = PathBuf::from(home);
+            paths.push(home.join("Library/Caches").join(bundle_id));
+            let data = home.join("Library/WebKit").join(bundle_id).join("WebsiteData");
+            for sub in ["CacheStorage", "ServiceWorkers", "DiskCache"] {
+                paths.push(data.join(sub));
+            }
+        }
+    }
+    #[cfg(target_os = "linux")]
+    if let Ok(home) = std::env::var("HOME") {
+        if !home.is_empty() {
+            let home = PathBuf::from(home);
+            let cache = std::env::var("XDG_CACHE_HOME")
+                .ok()
+                .filter(|v| !v.is_empty())
+                .map(PathBuf::from)
+                .unwrap_or_else(|| home.join(".cache"));
+            paths.push(cache.join(bundle_id));
+            // wry keys the WebKitGTK base-cache dir to the app data dir.
+            let data = std::env::var("XDG_DATA_HOME")
+                .ok()
+                .filter(|v| !v.is_empty())
+                .map(PathBuf::from)
+                .unwrap_or_else(|| home.join(".local/share"))
+                .join(bundle_id);
+            for sub in ["WebKitCache", "CacheStorage", "serviceworkers", "ServiceWorkers"] {
+                paths.push(data.join(sub));
+            }
+        }
+    }
+    for p in paths {
+        let _ = fs::remove_dir_all(&p);
+    }
+}
+
 fn main() {
     // Fix PATH for GUI apps (macOS .app bundles, Linux AppImage, Windows)
     // GUI apps don't inherit shell dotfile PATH — this spawns the user's
@@ -171,6 +229,11 @@ fn main() {
     info!("Unsloth Studio desktop app starting");
     windows_job::initialize();
 
+    // Must run before the Builder: the config-defined window (and its
+    // WebView, which locks these files) exists by the time setup hooks run.
+    let context = tauri::generate_context!();
+    clear_webview_caches(&context.config().identifier);
+
     tauri::Builder::default()
         .plugin(tauri_plugin_single_instance::init(|app, _args, _cwd| {
             if let Some(window) = app.get_webview_window("main") {
@@ -247,7 +310,7 @@ fn main() {
                 api.prevent_close();
             }
         })
-        .build(tauri::generate_context!())
+        .build(context)
         .expect("error while building tauri application")
         .run(|app, event| {
             if let tauri::RunEvent::Exit = event {
diff --git a/tests/run_all.sh b/tests/run_all.sh
index 1b5609c475..147aaf1645 100755
--- a/tests/run_all.sh
+++ b/tests/run_all.sh
@@ -14,7 +14,8 @@ sh "$TESTS_DIR/sh/test_nvcc_meets_llama_minimum.sh"
 sh "$TESTS_DIR/sh/test_resolve_cuda_archs.sh"
 sh "$TESTS_DIR/sh/test_strixhalo_wsl_reroute.sh"
 sh "$TESTS_DIR/sh/test_uninstall_shared_icon.sh"
-sh "$TESTS_DIR/sh/test_setup_webview_cache_clear.sh"
+# bash, not sh: the extracted setup.sh function uses bash arrays (dash chokes).
+bash "$TESTS_DIR/sh/test_setup_webview_cache_clear.sh"
 sh "$TESTS_DIR/sh/test_torch_flavor.sh"
 sh "$TESTS_DIR/sh/test_redact_install_output.sh"
 sh "$TESTS_DIR/sh/test_install_uv_override_space.sh"
diff --git a/tests/sh/test_setup_webview_cache_clear.sh b/tests/sh/test_setup_webview_cache_clear.sh
index de2ab157d2..19a3ee0064 100755
--- a/tests/sh/test_setup_webview_cache_clear.sh
+++ b/tests/sh/test_setup_webview_cache_clear.sh
@@ -53,23 +53,34 @@ assert_present "macOS: IndexedDB kept"                   "$H/Library/WebKit/$BID
 assert_present "macOS: Application Support kept"         "$H/Library/Application Support/$BID"
 assert_present "macOS: unrelated app cache kept"         "$H/Library/Caches/com.other.app"
 
-# ── 2. Linux: cache dir removed, data/config kept ──
+# ── 2. Linux: cache paths removed (XDG cache dir AND the cache subdirs wry
+# keys to the app data dir), user-facing storage kept ──
 H=$(mktemp -d -p "$_TMP_ROOT")
-mkdir -p "$H/.cache/$BID" "$H/.local/share/$BID" "$H/.config/$BID" "$H/.cache/other.app"
+D="$H/.local/share/$BID"
+mkdir -p "$H/.cache/$BID" "$D/WebKitCache" "$D/CacheStorage" "$D/serviceworkers" \
+         "$D/localstorage" "$D/indexeddb" "$H/.config/$BID" "$H/.cache/other.app"
+: > "$D/cookies.sqlite"
 uname() { echo Linux; }
-HOME="$H" XDG_CACHE_HOME="" _clear_webview_caches
-assert_gone    "linux: ~/.cache/$BID removed"     "$H/.cache/$BID"
-assert_present "linux: ~/.local/share/$BID kept"  "$H/.local/share/$BID"
-assert_present "linux: ~/.config/$BID kept"       "$H/.config/$BID"
-assert_present "linux: unrelated app cache kept"  "$H/.cache/other.app"
+HOME="$H" XDG_CACHE_HOME="" XDG_DATA_HOME="" _clear_webview_caches
+assert_gone    "linux: ~/.cache/$BID removed"          "$H/.cache/$BID"
+assert_gone    "linux: data-dir WebKitCache removed"   "$D/WebKitCache"
+assert_gone    "linux: data-dir CacheStorage removed"  "$D/CacheStorage"
+assert_gone    "linux: data-dir serviceworkers removed" "$D/serviceworkers"
+assert_present "linux: localstorage kept"              "$D/localstorage"
+assert_present "linux: indexeddb kept"                 "$D/indexeddb"
+assert_present "linux: cookies kept"                   "$D/cookies.sqlite"
+assert_present "linux: ~/.config/$BID kept"            "$H/.config/$BID"
+assert_present "linux: unrelated app cache kept"       "$H/.cache/other.app"
 
-# ── 3. Linux: XDG_CACHE_HOME override honored ──
+# ── 3. Linux: XDG_CACHE_HOME / XDG_DATA_HOME overrides honored ──
 H=$(mktemp -d -p "$_TMP_ROOT")
 XDG=$(mktemp -d -p "$_TMP_ROOT")
-mkdir -p "$XDG/$BID" "$H/.cache/$BID"
-HOME="$H" XDG_CACHE_HOME="$XDG" _clear_webview_caches
-assert_gone    "linux: XDG_CACHE_HOME/$BID removed"        "$XDG/$BID"
-assert_present "linux: ~/.cache/$BID kept under override"  "$H/.cache/$BID"
+mkdir -p "$XDG/cache/$BID" "$XDG/data/$BID/WebKitCache" "$XDG/data/$BID/localstorage" "$H/.cache/$BID"
+HOME="$H" XDG_CACHE_HOME="$XDG/cache" XDG_DATA_HOME="$XDG/data" _clear_webview_caches
+assert_gone    "linux: XDG_CACHE_HOME/$BID removed"          "$XDG/cache/$BID"
+assert_gone    "linux: XDG_DATA_HOME WebKitCache removed"    "$XDG/data/$BID/WebKitCache"
+assert_present "linux: XDG_DATA_HOME localstorage kept"      "$XDG/data/$BID/localstorage"
+assert_present "linux: ~/.cache/$BID kept under override"    "$H/.cache/$BID"
 
 # ── 4. Nothing to clear is a clean no-op ──
 H=$(mktemp -d -p "$_TMP_ROOT")