diff --git a/Cargo.lock b/Cargo.lock
index e883847e1..ed1d6710d 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1036,6 +1036,31 @@ dependencies = [
  "egui",
 ]
 
+[[package]]
+name = "craft-update"
+version = "0.1.0"
+source = "git+https://github.com/storytold/craft-libs?rev=db19c373c8d59a545972ca340987aecfb3611a4b#db19c373c8d59a545972ca340987aecfb3611a4b"
+dependencies = [
+ "chrono",
+ "dunce",
+ "egui",
+ "flate2",
+ "getrandom 0.3.4",
+ "log",
+ "plist",
+ "semver",
+ "serde",
+ "serde_json",
+ "sha2 0.10.9",
+ "tar",
+ "tempfile",
+ "ureq",
+ "verifysign",
+ "winreg",
+ "winsafe",
+ "zip 9.1.0",
+]
+
 [[package]]
 name = "craft-winprint-gdi"
 version = "0.1.0"
@@ -1163,6 +1188,12 @@ dependencies = [
  "syn 2.0.119",
 ]
 
+[[package]]
+name = "deranged"
+version = "0.5.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9e9de72ce2ad1f90dc62fa25f0f430ef85eb4b0d8fa0be4f30373bc40a21d28e"
+
 [[package]]
 name = "derive_arbitrary"
 version = "1.4.2"
@@ -1514,7 +1545,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "39cab71617ae0d63f51a36d69f866391735b51691dbda63cf6f96d042b63efeb"
 dependencies = [
  "libc",
- "windows-sys 0.61.2",
+ "windows-sys 0.60.2",
 ]
 
 [[package]]
@@ -3042,6 +3073,18 @@ dependencies = [
  "jni-sys 0.3.1",
 ]
 
+[[package]]
+name = "nix"
+version = "0.31.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cf20d2fde8ff38632c426f1165ed7436270b44f199fc55284c38276f9db47c3d"
+dependencies = [
+ "bitflags 2.13.2",
+ "cfg-if",
+ "cfg_aliases",
+ "libc",
+]
+
 [[package]]
 name = "nohash-hasher"
 version = "0.2.0"
@@ -3057,6 +3100,12 @@ dependencies = [
  "memchr",
 ]
 
+[[package]]
+name = "num-conv"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "521739c6d2bac4aa25192232afe6841231376b2b26d4d9fae5ecf8ca5772e441"
+
 [[package]]
 name = "num-traits"
 version = "0.2.19"
@@ -3467,7 +3516,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7d8fae84b431384b68627d0f9b3b1245fcf9f46f6c0e3dc902e9dce64edd1967"
 dependencies = [
  "libc",
- "windows-sys 0.61.2",
+ "windows-sys 0.60.2",
 ]
 
 [[package]]
@@ -3694,6 +3743,19 @@ version = "0.2.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b4596b6d070b27117e987119b4dac604f3c58cfb0b191112e24771b2faeac1a6"
 
+[[package]]
+name = "plist"
+version = "1.10.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "327a4cb2ad49dc48adfdc9da89e22c64d488b508c67a044d71ba729e4521a285"
+dependencies = [
+ "base64 0.23.1",
+ "indexmap",
+ "quick-xml 0.42.0",
+ "serde",
+ "time",
+]
+
 [[package]]
 name = "png"
 version = "0.18.1"
@@ -3778,6 +3840,12 @@ dependencies = [
  "zerovec",
 ]
 
+[[package]]
+name = "powerfmt"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4a6394b9e965e73d0a289ee54f589087e2c676aedf60885baf52c76b771e4958"
+
 [[package]]
 name = "ppv-lite86"
 version = "0.2.21"
@@ -3887,6 +3955,15 @@ dependencies = [
  "memchr",
 ]
 
+[[package]]
+name = "quick-xml"
+version = "0.42.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "41b1177fdf999d2321d3fb46ff47159d9c1fb9ad66a4879f8c50a0b504615e9b"
+dependencies = [
+ "memchr",
+]
+
 [[package]]
 name = "quinn"
 version = "0.11.12"
@@ -3941,7 +4018,7 @@ dependencies = [
  "once_cell",
  "socket2",
  "tracing",
- "windows-sys 0.61.2",
+ "windows-sys 0.60.2",
 ]
 
 [[package]]
@@ -4318,7 +4395,7 @@ dependencies = [
  "errno",
  "libc",
  "linux-raw-sys 0.12.1",
- "windows-sys 0.61.2",
+ "windows-sys 0.60.2",
 ]
 
 [[package]]
@@ -4328,7 +4405,9 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "48e13bd8c0e9365c43cfa5c9e8f9ad49d3c8444926c9aac819e0e4dc503c8fdf"
 dependencies = [
  "aws-lc-rs",
+ "log",
  "once_cell",
+ "ring",
  "rustls-pki-types",
  "rustls-webpki",
  "subtle",
@@ -4375,7 +4454,7 @@ dependencies = [
  "security-framework",
  "security-framework-sys",
  "webpki-root-certs",
- "windows-sys 0.61.2",
+ "windows-sys 0.60.2",
 ]
 
 [[package]]
@@ -4490,6 +4569,10 @@ name = "semver"
 version = "1.0.28"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8a7852d02fc848982e0c167ef163aaff9cd91dc640ba85e263cb1ce46fae51cd"
+dependencies = [
+ "serde",
+ "serde_core",
+]
 
 [[package]]
 name = "send_wrapper"
@@ -4973,7 +5056,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c3d1e2c7f27f8d4cb10542a02c49005dbd6e93095799d6f3be745fae9f8fedd4"
 dependencies = [
  "libc",
- "windows-sys 0.61.2",
+ "windows-sys 0.60.2",
 ]
 
 [[package]]
@@ -5158,7 +5241,7 @@ dependencies = [
  "getrandom 0.4.3",
  "once_cell",
  "rustix 1.1.5",
- "windows-sys 0.61.2",
+ "windows-sys 0.60.2",
 ]
 
 [[package]]
@@ -5233,6 +5316,36 @@ dependencies = [
  "zune-jpeg",
 ]
 
+[[package]]
+name = "time"
+version = "0.3.55"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cdb87b95ec50ddfa440816d227a17b2ccbdda963a316a727fda0fc4334f7d134"
+dependencies = [
+ "deranged",
+ "num-conv",
+ "powerfmt",
+ "serde_core",
+ "time-core",
+ "time-macros",
+]
+
+[[package]]
+name = "time-core"
+version = "0.1.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9e1c906769ad99c88eaa54e728060edef082f8e358ff32030cb7c7d315e81109"
+
+[[package]]
+name = "time-macros"
+version = "0.2.32"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7e689342a48d2ea927c87ea50cabf8594854bf940e9310208848d680d668ed85"
+dependencies = [
+ "num-conv",
+ "time-core",
+]
+
 [[package]]
 name = "tiny-skia-path"
 version = "0.12.0"
@@ -5474,6 +5587,12 @@ dependencies = [
  "rustc-hash 2.1.3",
 ]
 
+[[package]]
+name = "typed-path"
+version = "0.13.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9ce898823d8cd0f028662d2f349694b1af0a5cc9be83f1d213a00d3147445e1e"
+
 [[package]]
 name = "typenum"
 version = "1.20.1"
@@ -5488,7 +5607,7 @@ checksum = "f2f6fb2847f6742cd76af783a2a2c49e9375d0a111c7bef6f71cd9e738c72d6e"
 dependencies = [
  "memoffset",
  "tempfile",
- "windows-sys 0.61.2",
+ "windows-sys 0.60.2",
 ]
 
 [[package]]
@@ -5566,6 +5685,35 @@ version = "0.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8ecb6da28b8a351d773b68d5825ac39017e680750f980f3a1a85cd8dd28a47c1"
 
+[[package]]
+name = "ureq"
+version = "3.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cde93ff05758a36a851a398a772b0b79a82fbe3c186a46f2696baaeaf84c966b"
+dependencies = [
+ "base64 0.23.1",
+ "flate2",
+ "log",
+ "percent-encoding",
+ "rustls",
+ "rustls-pki-types",
+ "rustls-platform-verifier",
+ "ureq-proto",
+ "utf8-zero",
+]
+
+[[package]]
+name = "ureq-proto"
+version = "0.6.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "841583fc36089d7d59419568ae157f43a5a03a2e5a81ba87c77d1596ef46e922"
+dependencies = [
+ "base64 0.23.1",
+ "http",
+ "httparse",
+ "log",
+]
+
 [[package]]
 name = "url"
 version = "2.5.8"
@@ -5584,6 +5732,12 @@ version = "1.0.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c8232dd3cdaed5356e0f716d285e4b40b932ac434100fe9b7e0e8e935b9e6246"
 
+[[package]]
+name = "utf8-zero"
+version = "0.8.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b8c0a043c9540bae7c578c88f91dda8bd82e59ae27c21baca69c8b191aaf5a6e"
+
 [[package]]
 name = "utf8_iter"
 version = "1.0.4"
@@ -5634,6 +5788,16 @@ dependencies = [
  "vello_common",
 ]
 
+[[package]]
+name = "verifysign"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6acfcc42a8d44f340d001193d97ef56bf33210b51ad760ae8308c97d5241ca51"
+dependencies = [
+ "core-foundation 0.10.1",
+ "windows-sys 0.61.2",
+]
+
 [[package]]
 name = "version_check"
 version = "0.9.5"
@@ -5858,7 +6022,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "338e30461b3a2b67d70eb30a6d89f8e0c93a833e07d2ae89085cd070c4a00ac0"
 dependencies = [
  "proc-macro2",
- "quick-xml",
+ "quick-xml 0.41.0",
  "quote",
 ]
 
@@ -6114,7 +6278,7 @@ version = "0.1.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c2a7b1c03c876122aa43f3020e6c3c3ee5c05081c9a00739faf7503aeba10d22"
 dependencies = [
- "windows-sys 0.61.2",
+ "windows-sys 0.60.2",
 ]
 
 [[package]]
@@ -6483,6 +6647,16 @@ dependencies = [
  "xml",
 ]
 
+[[package]]
+name = "winreg"
+version = "0.55.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cb5a765337c50e9ec252c2069be9bf91c7df47afb103b642ba3a53bf8101be97"
+dependencies = [
+ "cfg-if",
+ "windows-sys 0.59.0",
+]
+
 [[package]]
 name = "winresource"
 version = "0.1.31"
@@ -6531,6 +6705,7 @@ dependencies = [
  "chrono",
  "clipboard-win",
  "craft-print",
+ "craft-update",
  "dispatch2",
  "eframe",
  "egui",
@@ -6617,7 +6792,7 @@ dependencies = [
  "image",
  "log",
  "proptest",
- "quick-xml",
+ "quick-xml 0.41.0",
  "sha1 0.11.0",
  "sha2 0.11.0",
  "thiserror 2.0.21",
@@ -6625,7 +6800,7 @@ dependencies = [
  "wordcraft-doc",
  "wordcraft-geom",
  "zeroize",
- "zip",
+ "zip 3.0.0",
 ]
 
 [[package]]
@@ -6656,7 +6831,7 @@ dependencies = [
  "wordcraft-proof",
  "wordcraft-render",
  "zeroize",
- "zip",
+ "zip 3.0.0",
 ]
 
 [[package]]
@@ -6684,10 +6859,10 @@ dependencies = [
  "js-sys",
  "log",
  "proptest",
- "quick-xml",
+ "quick-xml 0.41.0",
  "wordcraft-doc",
  "wordcraft-geom",
- "zip",
+ "zip 3.0.0",
 ]
 
 [[package]]
@@ -6791,6 +6966,7 @@ dependencies = [
  "chrono",
  "craft-i18n",
  "craft-ui",
+ "craft-update",
  "egui",
  "egui_kittest",
  "image",
@@ -6809,7 +6985,7 @@ dependencies = [
  "wordcraft-render",
  "wordcraft-zotero",
  "zbus",
- "zip",
+ "zip 3.0.0",
 ]
 
 [[package]]
@@ -7242,6 +7418,23 @@ dependencies = [
  "zopfli",
 ]
 
+[[package]]
+name = "zip"
+version = "9.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2886b00003a72c4ccee3f42cfc34908d33b2508a74d827dc2a4244706475c704"
+dependencies = [
+ "crc32fast",
+ "flate2",
+ "getrandom 0.4.3",
+ "indexmap",
+ "memchr",
+ "nix",
+ "typed-path",
+ "windows-sys 0.61.2",
+ "zopfli",
+]
+
 [[package]]
 name = "zlib-rs"
 version = "0.6.8"
diff --git a/Cargo.toml b/Cargo.toml
index 74175e376..bedb55537 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -55,6 +55,7 @@ wuff = "0.2.9"
 vello_cpu = "0.2"
 image = { version = "0.25", default-features = false, features = ["png", "jpeg", "webp", "gif", "bmp", "tiff"] }
 craft-pdf = { git = "https://github.com/storytold/craft-libs", rev = "17744430be327d0257496a6a31c8d38fe20a6756", version = "=0.1.0", default-features = false, features = ["write"] }
+craft-update = { git = "https://github.com/storytold/craft-libs", version = "=0.1.0", rev = "db19c373c8d59a545972ca340987aecfb3611a4b", features = ["egui"] }
 quick-xml = "0.41"
 zip = { version = "3", default-features = false, features = ["deflate"] }
 # zlib streams (compressed metafile pictures in `.doc` drawings); already in the lock as a dependency of other crates.
diff --git a/apps/wordcraft/Cargo.toml b/apps/wordcraft/Cargo.toml
index 828066e33..f1d27bc58 100644
--- a/apps/wordcraft/Cargo.toml
+++ b/apps/wordcraft/Cargo.toml
@@ -83,3 +83,6 @@ pollster = "0.4"
 arboard = { workspace = true, features = ["image-data"] }
 # The control server's random key.
 getrandom = "0.3"
+
+[target.'cfg(windows)'.dependencies]
+craft-update = { workspace = true }
diff --git a/apps/wordcraft/src/main.rs b/apps/wordcraft/src/main.rs
index 2073b5069..248696019 100644
--- a/apps/wordcraft/src/main.rs
+++ b/apps/wordcraft/src/main.rs
@@ -337,6 +337,11 @@ fn open_non_unicode(app: &mut WordApp, path: &std::path::Path) {
 /// geometry, opens requested documents or the Start screen, starts the control server when
 /// asked, and runs the eframe event loop.
 fn main() -> eframe::Result {
+    // Windows: the update helper is a copy of this program started with `--finish-update`.
+    #[cfg(windows)]
+    if let Some(result) = craft_update::self_update::finish(&craft_update::suite::WORDCRAFT, &std::env::args_os().skip(1).collect::<Vec<_>>()) {
+        std::process::exit(i32::from(result.is_err()));
+    }
     // First, so the panic hook and every start-up warning are recorded (`logging`).
     let logger = logging::install();
     logging::install_panic_hook();
@@ -445,6 +450,7 @@ fn main() -> eframe::Result {
             let mut session = Session::new(doc);
             session.system_region = region;
             let mut app = WordApp::new(session, services(file_dialog, &cc.egui_ctx));
+            app.set_startup_update_check(true);
             load_prefs(&mut app);
             load_user_dictionary(&mut app);
             // A region chosen in File › Options replaces the system's for the first blank
diff --git a/crates/ui-egui/Cargo.toml b/crates/ui-egui/Cargo.toml
index 3419c1a2c..1a257045f 100644
--- a/crates/ui-egui/Cargo.toml
+++ b/crates/ui-egui/Cargo.toml
@@ -42,6 +42,7 @@ zbus = "=5.19.0"
 # Comment times in the user's own time zone (`local_time.rs`); the web app asks the browser.
 [target.'cfg(not(target_arch = "wasm32"))'.dependencies]
 chrono = { version = "0.4.45", default-features = false, features = ["clock"] }
+craft-update = { workspace = true }
 
 [target.'cfg(target_arch = "wasm32")'.dependencies]
 # The browser clock (`SystemTime::now()`/`Instant::now()` panic on wasm32).
diff --git a/crates/ui-egui/src/lib.rs b/crates/ui-egui/src/lib.rs
index f546dead9..3a77229a7 100644
--- a/crates/ui-egui/src/lib.rs
+++ b/crates/ui-egui/src/lib.rs
@@ -83,6 +83,7 @@ pub mod table_pen;
 pub mod table_resize;
 pub mod table_ruler;
 pub mod theme;
+pub mod updates_ui;
 pub mod widgets;
 pub mod window_close;
 pub mod window_geometry;
@@ -568,6 +569,7 @@ pub struct WordApp {
     pub mac_titlebar: chrome::MacTitleBar,
     /// Focus (#1678): the ribbon is dropped down from the Focus bar, over the page.
     pub(crate) focus_ribbon: bool,
+    pub(crate) updates_rt: updates_ui::Runtime,
     control_rx: Option<std::sync::mpsc::Receiver<ControlRequest>>,
     /// Admitted `ui.screenshot` requests: count/byte budgets, retries and completion slots.
     shots: control::Shots,
@@ -735,6 +737,7 @@ impl WordApp {
             integrated_titlebar: false,
             mac_titlebar: chrome::MacTitleBar::default(),
             focus_ribbon: false,
+            updates_rt: updates_ui::Runtime::default(),
             control_rx: None,
             shots: control::Shots::default(),
             capture_epoch: 0,
@@ -1628,6 +1631,10 @@ impl WordApp {
     fn ui_command(&mut self, id: &str, p: &Value) -> Option<Result<Value, String>> {
         let s = |k: &str| p.get(k).and_then(Value::as_str);
         Some(Ok(match id {
+            "ui.checkForUpdates" | "help.checkForUpdates" => {
+                crate::updates_ui::check(self);
+                Value::Null
+            }
             "ui.tab" => {
                 let tab = s("tab").unwrap_or("Home").to_string();
                 if tab == "File" {
@@ -2244,6 +2251,7 @@ impl WordApp {
 
     /// Per-frame logic before layout: control requests, screenshots, shortcuts, file drops.
     pub fn logic(&mut self, ctx: &egui::Context) {
+        updates_ui::tick(self, ctx);
         let lang = i18n::Lang::from_pref(&self.ui.language);
         i18n::set_current(lang);
         // New documents are written in the interface's language when WordCraft can proof it
@@ -2637,6 +2645,7 @@ impl WordApp {
     fn show_overlays(&mut self, ui: &mut egui::Ui, ctx: &egui::Context) {
         content_controls::popup(self, ctx);
         dialogs::show(self, ctx);
+        updates_ui::show(self, ctx);
         #[cfg(not(target_arch = "wasm32"))]
         file_browser::show(self, ctx);
         colors::show(self, ctx);
@@ -3018,6 +3027,7 @@ pub(crate) fn works_without_document(id: &str) -> bool {
             | "ui.discord"
             | "ui.caretAnimation"
             | "ui.startScreen"
+            | "ui.checkForUpdates"
     ) || id.starts_with("help.")
 }
 
diff --git a/crates/ui-egui/src/ribbon.rs b/crates/ui-egui/src/ribbon.rs
index f0feb3204..0f498994b 100644
--- a/crates/ui-egui/src/ribbon.rs
+++ b/crates/ui-egui/src/ribbon.rs
@@ -2431,6 +2431,7 @@ fn outlining(app: &mut WordApp, ui: &mut Ui) {
 fn help(app: &mut WordApp, ui: &mut Ui) {
     group(ui, "Help", None, app, |ui, app| {
         big(ui, app, "help", "Help", "ui.dialog", json!({"name": "about"}), false);
+        big(ui, app, "checkForUpdates", "Check for\nUpdates…", "ui.checkForUpdates", json!({}), false);
         big(ui, app, "discord", "Community\nDiscord", "ui.discord", json!({}), false);
     });
     group(ui, "Agents", None, app, |ui, app| {
diff --git a/crates/ui-egui/src/updates_ui.rs b/crates/ui-egui/src/updates_ui.rs
new file mode 100644
index 000000000..c8aece1ff
--- /dev/null
+++ b/crates/ui-egui/src/updates_ui.rs
@@ -0,0 +1,133 @@
+//! Software updates, background check at startup, and startup prompt modal.
+
+use crate::WordApp;
+
+#[cfg(not(target_arch = "wasm32"))]
+use craft_update::updater::{Action, Status, Updater};
+
+pub(crate) struct Runtime {
+    #[cfg(not(target_arch = "wasm32"))]
+    updater: Updater,
+    /// The desktop app turns the check at start on; tests and the web build leave it off.
+    #[cfg(not(target_arch = "wasm32"))]
+    startup_check: bool,
+    #[cfg(not(target_arch = "wasm32"))]
+    check_requested: bool,
+    /// The context of the last frame, to wake the UI when a check is queued from a menu callback.
+    #[cfg(not(target_arch = "wasm32"))]
+    repaint: Option<egui::Context>,
+    pub(crate) manual_window_open: bool,
+    pub(crate) status_message: Option<String>,
+}
+
+impl Default for Runtime {
+    fn default() -> Self {
+        Self {
+            #[cfg(not(target_arch = "wasm32"))]
+            updater: Updater::new(&craft_update::suite::WORDCRAFT, env!("CARGO_PKG_VERSION")),
+            #[cfg(not(target_arch = "wasm32"))]
+            startup_check: false,
+            #[cfg(not(target_arch = "wasm32"))]
+            check_requested: false,
+            #[cfg(not(target_arch = "wasm32"))]
+            repaint: None,
+            manual_window_open: false,
+            status_message: None,
+        }
+    }
+}
+
+impl WordApp {
+    /// Whether the app asks for a newer release when it starts (off until the desktop app turns it on).
+    #[cfg(not(target_arch = "wasm32"))]
+    pub fn set_startup_update_check(&mut self, on: bool) {
+        self.updates_rt.startup_check = on;
+    }
+}
+
+pub(crate) fn check(app: &mut WordApp) {
+    #[cfg(not(target_arch = "wasm32"))]
+    {
+        app.updates_rt.check_requested = true;
+        if let Some(ctx) = &app.updates_rt.repaint {
+            ctx.request_repaint();
+        }
+    }
+    #[cfg(target_arch = "wasm32")]
+    {
+        app.updates_rt.manual_window_open = true;
+        app.updates_rt.status_message = Some(tl!("Update check is not supported in the web browser.").to_string());
+    }
+}
+
+pub(crate) fn tick(app: &mut WordApp, ctx: &egui::Context) {
+    #[cfg(not(target_arch = "wasm32"))]
+    {
+        let rt = &mut app.updates_rt;
+        rt.repaint = Some(ctx.clone());
+        if std::mem::take(&mut rt.check_requested) {
+            rt.updater.check_now(ctx);
+        } else if rt.startup_check {
+            rt.updater.check_at_start(ctx);
+        }
+        rt.updater.tick(ctx);
+    }
+    #[cfg(target_arch = "wasm32")]
+    let _ = (app, ctx);
+}
+
+pub(crate) fn show(app: &mut WordApp, ctx: &egui::Context) {
+    #[cfg(not(target_arch = "wasm32"))]
+    {
+        // The restart helper is scheduled before the app closes, so no update starts over unsaved work.
+        let clean = !(app.session.dirty || app.save_unconfirmed() || app.printing.busy() || crate::panes::has_comment_drafts(app));
+        match app.updates_rt.updater.show_if(ctx, clean) {
+            Action::OpenUrl(url) => ctx.open_url(egui::OpenUrl::new_tab(url)),
+            Action::Close => ctx.send_viewport_cmd(egui::ViewportCommand::Close),
+            Action::None => {}
+        }
+        // The window answers Help ▸ Check for Updates, so it follows the updater's status.
+        let rt = &mut app.updates_rt;
+        (rt.manual_window_open, rt.status_message) = match rt.updater.status() {
+            Status::Idle => (false, None),
+            Status::Checking => (true, None),
+            Status::UpToDate => {
+                (true, Some(tl!("WordCraft {version} is currently the newest version available.").replace("{version}", env!("CARGO_PKG_VERSION"))))
+            }
+            Status::Failed(e) => (true, Some(tl!("Could not check for updates:\n{error}").replace("{error}", e))),
+        };
+    }
+
+    if app.updates_rt.manual_window_open {
+        let mut open = true;
+        let mut close = false;
+        egui::Window::new(tl!("Check for Updates"))
+            .open(&mut open)
+            .resizable(false)
+            .collapsible(false)
+            .anchor(egui::Align2::CENTER_CENTER, egui::vec2(0.0, 0.0))
+            .show(ctx, |ui| {
+                if let Some(msg) = &app.updates_rt.status_message {
+                    ui.label(msg);
+                } else {
+                    ui.label(tl!("Checking for updates…"));
+                }
+                ui.add_space(8.0);
+                ui.with_layout(egui::Layout::right_to_left(egui::Align::Center), |ui| {
+                    if ui.button(tl!("Close")).clicked() {
+                        close = true;
+                    }
+                });
+            });
+        if !open || close {
+            app.updates_rt.manual_window_open = false;
+            app.updates_rt.status_message = None;
+        }
+    }
+
+    // Closing the window dismisses the outcome it showed.
+    #[cfg(not(target_arch = "wasm32"))]
+    if !app.updates_rt.manual_window_open {
+        app.updates_rt.updater.dismiss_status();
+    }
+}