diff --git a/crates/ui-egui/src/canvas.rs b/crates/ui-egui/src/canvas.rs
index 8c0555ea9..9895f1c56 100644
--- a/crates/ui-egui/src/canvas.rs
+++ b/crates/ui-egui/src/canvas.rs
@@ -3094,7 +3094,7 @@ fn recent(app: &mut VectorcraftApp, ui: &mut Ui) {
     for path in files {
         if recent_row(ui, &path).clicked() {
             // A failure is reported to the user there.
-            let _ = crate::io::open_reporting(app, &path);
+            let _ = crate::io::open_recent_reporting(app, &path);
         }
     }
 }
diff --git a/crates/ui-egui/src/io.rs b/crates/ui-egui/src/io.rs
index ae01b0305..7290da43b 100644
--- a/crates/ui-egui/src/io.rs
+++ b/crates/ui-egui/src/io.rs
@@ -214,6 +214,44 @@ pub fn open_reporting(app: &mut VectorcraftApp, path: &str) -> Result<Value, Str
     r
 }
 
+/// Home › Recent Files and File › Open Recent: focus an already-open tab for that path instead of
+/// calling `document.open` again (#3455).
+pub fn open_recent_reporting(app: &mut VectorcraftApp, path: &str) -> Result<Value, String> {
+    if let Some(r) = try_activate_open_document(app, path)? {
+        return Ok(r);
+    }
+    open_reporting(app, path)
+}
+
+fn try_activate_open_document(app: &mut VectorcraftApp, path: &str) -> Result<Option<Value>, String> {
+    let Some(index) = document_index_for_path(app, path) else {
+        return Ok(None);
+    };
+    let st = &app.session.documents()[index];
+    let r = json!({
+        "index": index,
+        "title": st.title(),
+        "format": st.format,
+        "warnings": [],
+        "restored": false,
+        "activated": true,
+    });
+    app.run("document.activate", json!({ "index": index }))?;
+    opened(app, &r);
+    Ok(Some(r))
+}
+
+fn document_index_for_path(app: &VectorcraftApp, path: &str) -> Option<usize> {
+    app.session.documents().iter().position(|st| st.path.as_deref().is_some_and(|p| same_open_path(p, path)))
+}
+
+fn same_open_path(a: &str, b: &str) -> bool {
+    match (std::fs::canonicalize(a), std::fs::canonicalize(b)) {
+        (Ok(a), Ok(b)) => a == b,
+        _ => a == b,
+    }
+}
+
 fn read(app: &VectorcraftApp, path: &str) -> Result<Vec<u8>, String> {
     app.services.read.as_ref().ok_or("no file reader")?(path)
 }
diff --git a/crates/ui-egui/src/menus.rs b/crates/ui-egui/src/menus.rs
index 16d1fd808..022c85ba4 100644
--- a/crates/ui-egui/src/menus.rs
+++ b/crates/ui-egui/src/menus.rs
@@ -1266,7 +1266,7 @@ pub fn run_ui_command(app: &mut VectorcraftApp, id: &str, p: &Value) -> Option<R
         "file.cancelExport" => Ok(io::cancel_exports(app)),
         "file.exportInBackground" => Ok(io::hide_exports(app)),
         id if id.starts_with("file.openRecent") => match recent_slot(app, id).cloned() {
-            Some(path) => io::open_reporting(app, &path),
+            Some(path) => io::open_recent_reporting(app, &path),
             None => Err("no such recent file".into()),
         },
         "type.findFont" => {
diff --git a/crates/ui-egui/src/tests_home.rs b/crates/ui-egui/src/tests_home.rs
index 4725552cc..86785557f 100644
--- a/crates/ui-egui/src/tests_home.rs
+++ b/crates/ui-egui/src/tests_home.rs
@@ -297,3 +297,31 @@ fn home_scrolls_in_a_short_window() {
     visible_home_texts(&mut app, &ctx, size, 4.1, vec![press(false)]);
     assert_eq!(app.session.documents().len(), 1, "the card opened its preset");
 }
+
+/// Home › Recent Files and File › Open Recent focus an open tab instead of opening a second copy
+/// (#3455); `document.open` is unchanged.
+#[test]
+fn home_recent_reopen_focuses_an_already_open_document() {
+    let services = crate::Services {
+        read: Some(Box::new(|p: &str| std::fs::read(p).map_err(|e| e.to_string()))),
+        write: Some(Box::new(|p: &str, b: &[u8]| std::fs::write(p, b).map_err(|e| e.to_string()))),
+        ..Default::default()
+    };
+    let mut app = VectorcraftApp::new(vectorcraft_engine::Session::new(), services);
+    let d = std::env::temp_dir().join(format!("vc-home-reopen-{}", std::process::id()));
+    let _ = std::fs::remove_dir_all(&d);
+    std::fs::create_dir_all(&d).unwrap();
+    let path = d.join("doc.vectorcraft").to_string_lossy().to_string();
+    app.run("file.new", json!({"width": 100, "height": 100})).unwrap();
+    app.run("shape.rectangle", json!({"x": 1, "y": 2, "width": 10, "height": 10})).unwrap();
+    app.run("file.saveAs", json!({"path": path})).unwrap();
+    app.run("file.new", json!({})).unwrap();
+    assert_eq!(app.session.documents().len(), 2);
+    assert_eq!(app.session.active_index(), Some(1));
+    let r = crate::io::open_recent_reporting(&mut app, &path).unwrap();
+    assert_eq!(r["activated"], true);
+    assert_eq!(app.session.documents().len(), 2);
+    assert_eq!(app.session.active_index(), Some(0));
+    assert_eq!(app.session.doc().unwrap().doc.layers[0].children().unwrap().len(), 1);
+    let _ = std::fs::remove_dir_all(d);
+}