diff --git a/crates/doc/src/canvas_range.rs b/crates/doc/src/canvas_range.rs
new file mode 100644
index 000000000..68658b58d
--- /dev/null
+++ b/crates/doc/src/canvas_range.rs
@@ -0,0 +1,185 @@
+//! A read document brought within the canvas: what lies beyond [`MAX_COORD`] is removed (#3575).
+//! Edits refuse to leave anything there (`doc_sane` in the engine checks the artboards, the guides,
+//! the ruler origin and the objects an edit touches), so a file holding something beyond it could be
+//! opened but not edited: one object, artboard or guide out there made every move fail.
+
+use std::sync::Arc;
+
+use vectorcraft_geom::{Point, Rect};
+
+use crate::{Document, MAX_COORD, Node, NodeKind};
+
+/// What [`Document::drop_beyond_canvas`] removed.
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
+pub struct BeyondCanvas {
+    /// Objects removed whole (a layer or group keeps its children within the canvas).
+    pub objects: usize,
+    pub artboards: usize,
+    /// Guides beyond the canvas, and the artboard guides of the artboards removed.
+    pub guides: usize,
+    /// The ruler origin was beyond the canvas and is back at the origin.
+    pub ruler_origin: bool,
+}
+
+impl BeyondCanvas {
+    /// The warning for what was removed, or `None` when nothing was.
+    pub fn note(&self) -> Option<String> {
+        let count = |n: usize, one: &str, many: &str| match n {
+            0 => None,
+            1 => Some(format!("1 {one}")),
+            n => Some(format!("{n} {many}")),
+        };
+        let parts: Vec<String> =
+            [count(self.objects, "object", "objects"), count(self.artboards, "artboard", "artboards"), count(self.guides, "guide", "guides")]
+                .into_iter()
+                .flatten()
+                .collect();
+        let limit = format!("more than {MAX_COORD} pt from the origin");
+        match (parts.is_empty(), self.ruler_origin) {
+            (true, false) => None,
+            (true, true) => Some(format!("the ruler origin lay beyond the canvas ({limit}) and was reset")),
+            (false, origin) => Some(format!(
+                "{} beyond the canvas ({limit}) {} removed{}",
+                parts.join(", "),
+                if self.objects + self.artboards + self.guides == 1 { "was" } else { "were" },
+                if origin { "; the ruler origin, beyond it too, was reset" } else { "" }
+            )),
+        }
+    }
+}
+
+/// Is every side of `r` finite and within [`MAX_COORD`] of the origin?
+fn rect_in_range(r: Rect) -> bool {
+    [r.x0, r.y0, r.x1, r.y1].iter().all(|v| in_range(*v))
+}
+
+fn in_range(v: f64) -> bool {
+    v.is_finite() && v.abs() <= MAX_COORD
+}
+
+/// Does `n` reach beyond the canvas? An object without geometry doesn't.
+fn beyond(n: &Node) -> bool {
+    n.geometric_bounds().is_some_and(|b| !rect_in_range(b))
+}
+
+/// Remove the children of `node` that reach beyond the canvas: a layer or group that isn't
+/// clipping keeps those of its own children within it, anything else goes whole. Only a node
+/// with such a child is copied. Recursion follows the nesting, which [`Document::limit_depth`]
+/// bounds.
+fn drop_children_beyond(node: &mut Arc<Node>, dropped: &mut usize) {
+    if !node.children().is_some_and(|c| c.iter().any(|c| beyond(c))) {
+        return;
+    }
+    let Some(children) = Arc::make_mut(node).children_mut() else { return };
+    children.retain_mut(|c| {
+        if !beyond(c) {
+            return true;
+        }
+        if matches!(c.kind, NodeKind::Layer { clip: false, .. } | NodeKind::Group { clip: false, .. }) {
+            drop_children_beyond(c, dropped);
+            return true;
+        }
+        *dropped += 1;
+        false
+    });
+}
+
+impl Document {
+    /// Remove what a read file has beyond the canvas ([`MAX_COORD`], or not finite): objects
+    /// (see [`BeyondCanvas::objects`]), artboards, and guides with the artboard guides of those
+    /// artboards, and put a ruler origin beyond it back at the origin. Run after
+    /// [`Document::limit_depth`]. A document whose artboards were all removed has none left.
+    pub fn drop_beyond_canvas(&mut self) -> BeyondCanvas {
+        let mut gone = BeyondCanvas::default();
+        for layer in &mut self.layers {
+            drop_children_beyond(layer, &mut gone.objects);
+        }
+        let removed: Vec<u32> = self.artboards.iter().filter(|a| !rect_in_range(a.rect)).map(|a| a.id).collect();
+        self.artboards.retain(|a| rect_in_range(a.rect));
+        gone.artboards = removed.len();
+        let guides = self.guides.len();
+        self.guides.retain(|g| in_range(g.pos) && g.artboard.is_none_or(|a| !removed.contains(&a)));
+        gone.guides = guides - self.guides.len();
+        if !(in_range(self.ruler_origin.x) && in_range(self.ruler_origin.y)) {
+            self.ruler_origin = Point::ZERO;
+            gone.ruler_origin = true;
+        }
+        gone
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::{Appearance, Artboard, Guide, NodeId};
+    use vectorcraft_geom::shapes;
+
+    fn rect(id: u64, y: f64) -> Arc<Node> {
+        Arc::new(Node::path(NodeId(id), shapes::rectangle(Rect::new(0.0, y, 10.0, y + 10.0)), Appearance::default_art()))
+    }
+
+    fn doc(children: Vec<Arc<Node>>) -> Document {
+        let mut d = Document::new(100.0, 100.0);
+        if let Some(ch) = d.layers.first_mut().and_then(|l| Arc::make_mut(l).children_mut()) {
+            ch.extend(children);
+        }
+        d
+    }
+
+    fn ids(d: &Document) -> Vec<u64> {
+        let mut out = vec![];
+        fn walk(n: &Node, out: &mut Vec<u64>) {
+            out.push(n.id.0);
+            for c in n.children().into_iter().flatten() {
+                walk(c, out);
+            }
+        }
+        for l in &d.layers {
+            walk(l, &mut out);
+        }
+        out
+    }
+
+    #[test]
+    fn a_document_within_the_canvas_is_left_alone() {
+        let mut d = doc(vec![rect(10, 0.0), rect(11, MAX_COORD - 10.0), rect(12, -MAX_COORD)]);
+        let before = d.clone();
+        assert_eq!(d.drop_beyond_canvas(), BeyondCanvas::default());
+        assert_eq!(d, before);
+        assert_eq!(BeyondCanvas::default().note(), None);
+    }
+
+    #[test]
+    fn objects_beyond_the_canvas_are_removed_and_groups_keep_the_rest() {
+        let group = Arc::new(Node::group(NodeId(20), vec![rect(21, 0.0), rect(22, 1e17)]));
+        let clip = Arc::new(Node::new(NodeId(30), NodeKind::Group { children: vec![rect(31, f64::NAN), rect(32, 0.0)], clip: true }));
+        let mut d = doc(vec![rect(10, 0.0), rect(11, 1e17), group, clip, rect(12, -MAX_COORD - 1.0)]);
+        let layer = d.layers[0].id.0;
+        let gone = d.drop_beyond_canvas();
+        assert_eq!(gone, BeyondCanvas { objects: 4, ..Default::default() });
+        assert_eq!(ids(&d), [layer, 10, 20, 21], "the group keeps its object within the canvas; the clip group goes with its clipping path");
+        assert!(d.layers.iter().all(|l| !beyond(l)));
+        assert_eq!(gone.note().unwrap(), format!("4 objects beyond the canvas (more than {MAX_COORD} pt from the origin) were removed"));
+    }
+
+    #[test]
+    fn artboards_guides_and_the_ruler_origin_beyond_the_canvas_are_removed_or_reset() {
+        let mut d = doc(vec![rect(10, 0.0)]);
+        let far = Artboard { id: 9, rect: Rect::new(0.0, 1e17, 100.0, 1e17 + 100.0), ..d.artboards[0].clone() };
+        d.artboards.push(far);
+        let guide = |pos: f64, artboard| Guide { artboard, ..Guide::new(false, pos) };
+        d.guides = vec![guide(50.0, None), guide(1e17, None), guide(f64::INFINITY, None), guide(20.0, Some(9))];
+        d.ruler_origin = Point::new(1e17, 0.0);
+        let gone = d.drop_beyond_canvas();
+        assert_eq!(gone, BeyondCanvas { objects: 0, artboards: 1, guides: 3, ruler_origin: true });
+        assert_eq!(d.artboards.len(), 1);
+        assert_eq!(d.guides, [guide(50.0, None)], "the far artboard's own guide goes with it");
+        assert_eq!(d.ruler_origin, Point::ZERO);
+        assert_eq!(
+            gone.note().unwrap(),
+            format!(
+                "1 artboard, 3 guides beyond the canvas (more than {MAX_COORD} pt from the origin) were removed; the ruler origin, beyond it too, was reset"
+            )
+        );
+    }
+}
diff --git a/crates/doc/src/lib.rs b/crates/doc/src/lib.rs
index 18873d6d9..91ede3df9 100644
--- a/crates/doc/src/lib.rs
+++ b/crates/doc/src/lib.rs
@@ -117,6 +117,7 @@ use vectorcraft_color::{Swatch, SwatchGroup};
 use vectorcraft_geom::{Affine, Point, Rect, Vec2};
 
 mod artboard;
+mod canvas_range;
 mod document;
 mod document_ext;
 mod document_guides;
@@ -127,6 +128,7 @@ mod records;
 mod units;
 
 pub use artboard::{Artboard, LockedArtboards, RetiredArtboardId, VIDEO_PIXEL_ASPECT_RANGE, VIDEO_SAFE_INSETS};
+pub use canvas_range::BeyondCanvas;
 #[cfg(test)]
 use document_ext::free_id;
 pub use graphic_style::{DEFAULT_GRAPHIC_STYLE, GraphicStyle};
diff --git a/crates/engine/tests/it/beyond_canvas.rs b/crates/engine/tests/it/beyond_canvas.rs
new file mode 100644
index 000000000..9dee868d5
--- /dev/null
+++ b/crates/engine/tests/it/beyond_canvas.rs
@@ -0,0 +1,69 @@
+//! #3575: a native file holding an object, artboard, guide or ruler origin beyond the canvas
+//! (`MAX_COORD`) opened, but every move then failed with "result would exceed the canvas": edits
+//! check those. Opening it now removes them (or resets the ruler origin) and says so.
+
+use serde_json::{Value, json};
+use vectorcraft_engine::Session;
+
+/// A saved two-rectangle document as JSON, with its first rectangle 1e17 pt down when `far_object`.
+fn document(far_object: bool) -> Value {
+    let mut s = Session::new();
+    s.execute("file.new", &json!({"width": 200, "height": 200})).unwrap();
+    s.execute("shape.rectangle", &json!({"x": 10, "y": 10, "width": 50, "height": 30})).unwrap();
+    s.execute("shape.rectangle", &json!({"x": 100, "y": 100, "width": 20, "height": 20})).unwrap();
+    let mut v: Value = serde_json::from_slice(&vectorcraft_format::save(&s.doc().unwrap().doc, false)).unwrap();
+    if far_object {
+        let far = &mut v["document"]["layers"][0]["kind"]["children"][0]["kind"];
+        far["path"]["subpaths"][0]["anchors"].as_array_mut().unwrap().iter_mut().for_each(|a| a["p"][1] = json!(a["p"][1].as_f64().unwrap() + 1e17));
+        far["live"]["xf"][5] = json!(far["live"]["xf"][5].as_f64().unwrap() + 1e17);
+    }
+    v
+}
+
+/// Open `v` from a file, select everything and move it: → the open reply's warnings.
+fn open_and_move(v: &Value, tag: &str) -> (Session, Value) {
+    let path = std::env::temp_dir().join(format!("vectorcraft-beyond-canvas-{tag}-{}.vectorcraft", std::process::id()));
+    std::fs::write(&path, serde_json::to_vec(v).unwrap()).unwrap();
+    let mut s = Session::new();
+    let opened = s.execute("document.open", &json!({"path": path}));
+    let _ = std::fs::remove_file(&path);
+    let opened = opened.unwrap();
+    s.execute("select.all", &json!({})).unwrap();
+    s.execute("object.move", &json!({"dx": 5, "dy": 5})).expect("everything left can be moved");
+    (s, opened["warnings"].clone())
+}
+
+#[test]
+fn an_object_beyond_the_canvas_is_removed_on_open() {
+    let (s, warnings) = open_and_move(&document(true), "object");
+    assert_eq!(s.doc().unwrap().doc.layers[0].children().unwrap().len(), 1, "the far rectangle is gone, the other stays");
+    assert!(warnings.to_string().contains("1 object beyond the canvas"), "{warnings}");
+}
+
+#[test]
+fn an_artboard_a_guide_or_a_ruler_origin_beyond_the_canvas_no_longer_blocks_edits() {
+    let mut v = document(false);
+    let mut far = v["document"]["artboards"][0].clone();
+    far["id"] = json!(9);
+    far["rect"] = json!({"x0": 0.0, "y0": 1e17, "x1": 100.0, "y1": 1e17 + 100.0});
+    v["document"]["artboards"].as_array_mut().unwrap().push(far);
+    v["document"]["guides"] = json!([{"vertical": false, "pos": 1e17}, {"vertical": true, "pos": 50.0}]);
+    v["document"]["ruler_origin"] = json!([1e17, 0.0]);
+    let (s, warnings) = open_and_move(&v, "setup");
+    let d = &s.doc().unwrap().doc;
+    assert_eq!((d.artboards.len(), d.guides.len(), d.ruler_origin.x), (1, 1, 0.0));
+    assert!(warnings.to_string().contains("1 artboard, 1 guide beyond the canvas"), "{warnings}");
+    assert!(warnings.to_string().contains("ruler origin"), "{warnings}");
+}
+
+#[test]
+fn a_file_whose_artboards_all_lie_beyond_the_canvas_is_refused() {
+    let mut v = document(false);
+    v["document"]["artboards"][0]["rect"] = json!({"x0": 0.0, "y0": 1e17, "x1": 100.0, "y1": 1e17 + 100.0});
+    let path = std::env::temp_dir().join(format!("vectorcraft-beyond-canvas-pages-{}.vectorcraft", std::process::id()));
+    std::fs::write(&path, serde_json::to_vec(&v).unwrap()).unwrap();
+    let r = Session::new().execute("document.open", &json!({"path": path}));
+    let _ = std::fs::remove_file(&path);
+    let e = r.unwrap_err().to_string();
+    assert!(e.contains("artboards all lie beyond the canvas"), "{e}");
+}
diff --git a/crates/engine/tests/it/main.rs b/crates/engine/tests/it/main.rs
index b0409cffd..5b9dc39c6 100644
--- a/crates/engine/tests/it/main.rs
+++ b/crates/engine/tests/it/main.rs
@@ -10,6 +10,7 @@ mod text_fixture;
 mod affinity_features;
 mod affinity_local;
 mod artboard_click;
+mod beyond_canvas;
 mod clear_commands;
 mod compound_attributes;
 mod dimensions;
diff --git a/crates/format/src/lib.rs b/crates/format/src/lib.rs
index 0e65fcb66..ad9df39ff 100644
--- a/crates/format/src/lib.rs
+++ b/crates/format/src/lib.rs
@@ -522,7 +522,8 @@ pub fn load(bytes: &[u8]) -> Result<Document, FormatError> {
 pub struct NativeFile {
     pub doc: Document,
     /// What was done to bring the document within the nesting caps
-    /// ([`Document::limit_depth_noting`]: a file saved before them, or a damaged one).
+    /// ([`Document::limit_depth_noting`]: a file saved before them, or a damaged one) and within
+    /// the canvas ([`Document::drop_beyond_canvas`]: a damaged or hand-made file).
     pub depth_notes: Vec<String>,
     pub info: FileInfo,
     /// ICC files by profile name (saved with Embed ICC Profiles; undecodable ones are left out).
@@ -617,6 +618,17 @@ fn load_file_within(bytes: &[u8], max_nodes: usize, max_values: usize) -> Result
     doc.raster_effects.add_around = doc.raster_effects.add_around.clamp(0.0, vectorcraft_doc::rastersettings::MAX_ADD_AROUND);
     let mut depth_notes = vec![];
     doc.limit_depth_noting(&mut depth_notes);
+    // Untrusted: nothing beyond the canvas, where no edit may leave anything (after the depth
+    // limit: the walk recurses). A file whose artboards all lie there has no page to show (#3575).
+    let had_artboards = !doc.artboards.is_empty();
+    let beyond = doc.drop_beyond_canvas();
+    if had_artboards && doc.artboards.is_empty() {
+        return Err(FormatError::NotVectorcraft(format!(
+            "its artboards all lie beyond the canvas (more than {} pt from the origin)",
+            vectorcraft_doc::MAX_COORD
+        )));
+    }
+    depth_notes.extend(beyond.note());
     // Untrusted: the type's sizes, leading, baseline shifts and scales, its indents and paragraph
     // spacing, and its tab stops, each within its range (after the depth limit: the walk recurses).
     doc.keep_type_values_in_range();