diff --git a/crates/ui-egui/src/canvas/input.rs b/crates/ui-egui/src/canvas/input.rs
--- a/crates/ui-egui/src/canvas/input.rs
+++ b/crates/ui-egui/src/canvas/input.rs
@@ -13,11 +13,12 @@ use super::*;
 pub(super) fn handle_input(app: &mut VectorcraftApp, ui: &Ui, resp: &egui::Response, rect: egui::Rect) {
     let line = ui.ctx().options(|o| o.input_options.line_scroll_speed);
     let wheel_zooms = app.session.prefs.zoom_with_mouse_wheel;
+    let animate = animated_zoom(&app.session.prefs);
     let turn_id = egui::Id::unique("canvas-wheel-turn");
     let turn_before: WheelTurn = ui.data(|d| d.get_temp(turn_id)).unwrap_or_default();
     let mut turn = turn_before;
     let (pointer, m, space, (factor, scroll)) =
-        ui.input(|i| (i.pointer.clone(), i.modifiers, i.key_down(egui::Key::Space), wheel(i, wheel_zooms, line, rect.height(), &mut turn)));
+        ui.input(|i| (i.pointer.clone(), i.modifiers, i.key_down(egui::Key::Space), wheel(i, wheel_zooms, animate, line, rect.height(), &mut turn)));
     if turn != turn_before {
         ui.data_mut(|d| d.insert_temp(turn_id, turn));
     }
diff --git a/crates/ui-egui/src/canvas/tests.rs b/crates/ui-egui/src/canvas/tests.rs
--- a/crates/ui-egui/src/canvas/tests.rs
+++ b/crates/ui-egui/src/canvas/tests.rs
@@ -3765,6 +3765,49 @@ fn wheel_notches_zoom_in_a_glide() {
     assert_eq!(app.view().unwrap().zoom / before, done, "and it stops");
 }
 
+/// #4283: with Performance › Animated Zoom off, a wheel notch zooms the whole step on the frame
+/// it arrives, both the plain wheel with Zoom with Mouse Wheel and Alt-wheel without it.
+#[test]
+fn wheel_notches_zoom_at_once_without_animated_zoom() {
+    let mut app = VectorcraftApp::new(Session::new(), Default::default());
+    app.session.execute("file.new", &json!({"width": 400, "height": 300})).unwrap();
+    app.session.execute("prefs.set", &json!({"key": "animatedZoom", "value": false})).unwrap();
+    let ctx = egui::Context::default();
+    let run = |app: &mut VectorcraftApp| {
+        let mut raw = egui::RawInput { screen_rect: Some(egui::Rect::from_min_size(Pos2::ZERO, vec2(800.0, 600.0))), ..Default::default() };
+        app.raw_input_hook(&ctx, &mut raw);
+        let mut out = ctx.run_ui(raw, |ui| show(app, ui));
+        out.textures_delta.clear();
+    };
+    run(&mut app);
+    let at = app.canvas_rect.unwrap().center();
+    for (wheel_zooms, alt) in [(true, false), (false, true)] {
+        app.session.execute("prefs.set", &json!({"key": "zoomWithMouseWheel", "value": wheel_zooms})).unwrap();
+        let before = app.view().unwrap().zoom;
+        crate::tests_synthetic::control(&mut app, &ctx, "ui.wheel", json!({"x": at.x, "y": at.y, "dy": 1, "alt": alt}));
+        // One line notch's whole zoom.
+        let expected = ctx.options(|o| f64::from(o.input_options.line_scroll_speed) * 0.01).exp();
+        // The first frame the zoom moves (the event may land a frame later).
+        let mut first = 1.0;
+        for _ in 0..3 {
+            run(&mut app);
+            first = app.view().unwrap().zoom / before;
+            if first != 1.0 {
+                break;
+            }
+        }
+        assert!(
+            (first - expected).abs() < 1e-9,
+            "the whole notch arrives at once (wheel zooms {wheel_zooms}, alt {alt}: expected {expected}, got {first})"
+        );
+        for _ in 0..30 {
+            run(&mut app);
+        }
+        let done = app.view().unwrap().zoom / before;
+        assert!((done - first).abs() < 1e-9, "all of it on the first frame (wheel zooms {wheel_zooms}, alt {alt}: {first} then {done})");
+    }
+}
+
 /// In each frame where a wheel scroll moves the view, the hover point (read by the rulers'
 /// pointer marks, the Info panel, the hover highlight and the tool cursor) is the document point
 /// under the pointer in the view the canvas draws in that frame.
diff --git a/crates/ui-egui/src/canvas/view.rs b/crates/ui-egui/src/canvas/view.rs
--- a/crates/ui-egui/src/canvas/view.rs
+++ b/crates/ui-egui/src/canvas/view.rs
@@ -64,7 +64,8 @@ pub(super) const HOLD_DELAY: f32 = 0.3;
 pub(super) const HOLD_ZOOM: f64 = std::f64::consts::LN_2;
 
 /// Performance › Animated Zoom, which needs GPU Performance as in Illustrator: the Zoom tool zooms
-/// as it is dragged sideways or held, instead of zooming to the area dragged across.
+/// as it is dragged sideways or held, instead of zooming to the area dragged across, and a wheel
+/// notch's zoom glides in ([`wheel`]).
 pub(crate) fn animated_zoom(p: &vectorcraft_engine::Prefs) -> bool {
     p.animated_zoom && p.gpu_performance
 }
@@ -336,11 +337,19 @@ struct ThumbDrag {
 /// a zoom factor (about the pointer) and a scroll (screen points the content moves). The wheel scrolls, Cmd- and Alt-wheel (Option
 /// on the Mac) zoom. With General › Zoom with Mouse Wheel (`wheel_zooms`) the wheel and Alt-wheel
 /// zoom, Shift-wheel scrolls up and down and Cmd/Ctrl-wheel sideways. `line` and `page`: points
-/// per wheel line and page. `turn`: kept by the caller across frames. A mouse wheel's notches zoom
-/// in a glide over a few frames, as scrolling does (#888); a trackpad's fine steps at once.
-pub(super) fn wheel(i: &egui::InputState, wheel_zooms: bool, line: f32, page: f32, turn: &mut WheelTurn) -> (f64, egui::Vec2) {
+/// per wheel line and page. `turn`: kept by the caller across frames. With Performance › Animated
+/// Zoom (`animate`) a mouse wheel's notches zoom in a glide over a few frames, as scrolling does
+/// (#888); off, each notch zooms on the frame it arrives (#4283). A trackpad's fine steps zoom at
+/// once either way.
+pub(super) fn wheel(i: &egui::InputState, wheel_zooms: bool, animate: bool, line: f32, page: f32, turn: &mut WheelTurn) -> (f64, egui::Vec2) {
     // Fingers on a touch screen pan the content with them (a trackpad sends scrolls instead).
     let pan = i.multi_touch().map_or(egui::Vec2::ZERO, |t| t.translation_delta);
+    // A wheel event's motion in points.
+    let points = |unit: &egui::MouseWheelUnit, delta: egui::Vec2| match unit {
+        egui::MouseWheelUnit::Point => delta,
+        egui::MouseWheelUnit::Line => delta * line,
+        egui::MouseWheelUnit::Page => delta * page,
+    };
     if !wheel_zooms {
         // egui makes Cmd-wheel (and a pinch) its zoom and the rest a scroll it spreads over a few
         // frames: the rest of an Alt-wheel turn zooms too, however soon Alt is let go.
@@ -348,6 +357,17 @@ pub(super) fn wheel(i: &egui::InputState, wheel_zooms: bool, line: f32, page: f3
             turn.alt = m.alt && !m.command;
         }
         let (zoom, scroll) = (f64::from(i.zoom_delta()), i.smooth_scroll_delta);
+        if turn.alt && !animate {
+            // Without Animated Zoom, Alt-wheel zooms by the wheel events themselves, on the frame
+            // they arrive; the rest of egui's spread scroll is dropped.
+            let d: f32 = i
+                .events
+                .iter()
+                .filter_map(|e| if let egui::Event::MouseWheel { unit, delta, .. } = e { Some(points(unit, *delta)) } else { None })
+                .map(|d| d.x + d.y)
+                .sum();
+            return (zoom * (f64::from(d) * WHEEL_ZOOM).exp(), pan);
+        }
         return if turn.alt && scroll != egui::Vec2::ZERO {
             (zoom * (f64::from(scroll.x + scroll.y) * WHEEL_ZOOM).exp(), pan)
         } else {
@@ -360,16 +380,12 @@ pub(super) fn wheel(i: &egui::InputState, wheel_zooms: bool, line: f32, page: f3
     for e in &i.events {
         match e {
             egui::Event::MouseWheel { unit, delta, modifiers, .. } => {
-                let d = match unit {
-                    egui::MouseWheelUnit::Point => *delta,
-                    egui::MouseWheelUnit::Line => *delta * line,
-                    egui::MouseWheelUnit::Page => *delta * page,
-                };
+                let d = points(unit, *delta);
                 if modifiers.command {
                     scroll.x += d.x + d.y;
                 } else if modifiers.shift {
                     scroll.y += d.x + d.y;
-                } else if *unit == egui::MouseWheelUnit::Point {
+                } else if *unit == egui::MouseWheelUnit::Point || !animate {
                     zoom *= (f64::from(d.y) * WHEEL_ZOOM).exp();
                     scroll.x += d.x;
                 } else {