diff --git a/Cargo.lock b/Cargo.lock
index b46aa6550..92227fc93 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1144,7 +1144,7 @@ dependencies = [
 [[package]]
 name = "craft-eps"
 version = "0.1.0"
-source = "git+https://github.com/storytold/craft-libs?rev=6ba1ca33ca21c33de55ef155141db08ca6048e8d#6ba1ca33ca21c33de55ef155141db08ca6048e8d"
+source = "git+https://github.com/storytold/craft-libs?rev=b4ada28f1#b4ada28f19067d4693e902e0e5f32eb292241e3a"
 
 [[package]]
 name = "craft-eps"
@@ -1164,10 +1164,10 @@ dependencies = [
 [[package]]
 name = "craft-file-formats"
 version = "0.1.0"
-source = "git+https://github.com/storytold/craft-libs?rev=6ba1ca33ca21c33de55ef155141db08ca6048e8d#6ba1ca33ca21c33de55ef155141db08ca6048e8d"
+source = "git+https://github.com/storytold/craft-libs?rev=b4ada28f1#b4ada28f19067d4693e902e0e5f32eb292241e3a"
 dependencies = [
- "craft-eps 0.1.0 (git+https://github.com/storytold/craft-libs?rev=6ba1ca33ca21c33de55ef155141db08ca6048e8d)",
- "craft-svg 0.1.0 (git+https://github.com/storytold/craft-libs?rev=6ba1ca33ca21c33de55ef155141db08ca6048e8d)",
+ "craft-eps 0.1.0 (git+https://github.com/storytold/craft-libs?rev=b4ada28f1)",
+ "craft-svg 0.1.0 (git+https://github.com/storytold/craft-libs?rev=b4ada28f1)",
 ]
 
 [[package]]
@@ -1362,9 +1362,9 @@ source = "git+https://github.com/storytold/craft-libs?rev=ba24fe2435adb3c81ad605
 [[package]]
 name = "craft-svg"
 version = "0.1.0"
-source = "git+https://github.com/storytold/craft-libs?rev=6ba1ca33ca21c33de55ef155141db08ca6048e8d#6ba1ca33ca21c33de55ef155141db08ca6048e8d"
+source = "git+https://github.com/storytold/craft-libs?rev=b4ada28f1#b4ada28f19067d4693e902e0e5f32eb292241e3a"
 dependencies = [
- "craft-xml 0.1.0 (git+https://github.com/storytold/craft-libs?rev=6ba1ca33ca21c33de55ef155141db08ca6048e8d)",
+ "craft-xml 0.1.0 (git+https://github.com/storytold/craft-libs?rev=b4ada28f1)",
  "flate2",
  "kurbo",
  "roxmltree 0.21.2",
@@ -1479,7 +1479,7 @@ dependencies = [
 [[package]]
 name = "craft-xml"
 version = "0.1.0"
-source = "git+https://github.com/storytold/craft-libs?rev=6ba1ca33ca21c33de55ef155141db08ca6048e8d#6ba1ca33ca21c33de55ef155141db08ca6048e8d"
+source = "git+https://github.com/storytold/craft-libs?rev=b4ada28f1#b4ada28f19067d4693e902e0e5f32eb292241e3a"
 dependencies = [
  "quick-xml 0.41.0",
  "thiserror 2.0.21",
@@ -1967,6 +1967,7 @@ name = "designcraft-ui-egui"
 version = "0.20.1"
 dependencies = [
  "craft-dialogs",
+ "craft-file-formats",
  "craft-keymap",
  "craft-prepress",
  "craft-ui",
diff --git a/Cargo.toml b/Cargo.toml
index 2b2f09020..74359a740 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -26,7 +26,7 @@ craft-docx = { git = "https://github.com/storytold/craft-libs", rev = "ba24fe243
 craft-wordmodel = { git = "https://github.com/storytold/craft-libs", rev = "ba24fe2435adb3c81ad6057faf36365fbba736cf", version = "=0.1.0" }
 craft-image-codecs = { git = "https://github.com/storytold/craft-libs", rev = "a47b78256c6acf3d7fdc4bc7cfbc25c373eac522", version = "=0.1.0" }
 craft-psd = { git = "https://github.com/storytold/craft-libs", rev = "a47b78256c6acf3d7fdc4bc7cfbc25c373eac522", version = "=0.1.0" }
-craft-file-formats = { git = "https://github.com/storytold/craft-libs", rev = "6ba1ca33ca21c33de55ef155141db08ca6048e8d", version = "=0.1.0" }
+craft-file-formats = { git = "https://github.com/storytold/craft-libs", rev = "b4ada28f1", version = "=0.1.0" }
 # Shared keyboard bindings: chords, overrides, conflicts, egui dispatch, the Keyboard Shortcuts dialog.
 craft-keymap = { git = "https://github.com/storytold/craft-libs", rev = "92d392cff132eaf53e13afff77f38b5c11b73aa0", version = "=0.1.0", features = ["egui", "ui"] }
 # Separations, ink coverage and the ink manager; same revision as craft-pdf and the krilla patch.
diff --git a/crates/engine/src/cmd/export/formats.rs b/crates/engine/src/cmd/export/formats.rs
index a25553d69..845b9b1d7 100644
--- a/crates/engine/src/cmd/export/formats.rs
+++ b/crates/engine/src/cmd/export/formats.rs
@@ -136,7 +136,7 @@ pub(super) fn export_text(s: &mut Session, p: &Value) -> Result<Value> {
         Some(f @ ("rtf" | "tagged")) => f,
         Some("txt") | Some("text") => "txt",
         Some(f) => return Err(bad(ID, format!("unknown format `{f}` (txt, rtf, tagged)"))),
-        None if path.is_some_and(|x| x.to_ascii_lowercase().ends_with(".rtf")) => "rtf",
+        None if path.is_some_and(|x| craft_file_formats::detect(x, &[]) == Some(craft_file_formats::Format::Rtf)) => "rtf",
         None => "txt",
     };
     let text = match format {
diff --git a/crates/engine/src/cmd/file/bytes.rs b/crates/engine/src/cmd/file/bytes.rs
index 5fd6d4e0b..f169b74e4 100644
--- a/crates/engine/src/cmd/file/bytes.rs
+++ b/crates/engine/src/cmd/file/bytes.rs
@@ -21,7 +21,7 @@ fn save_bytes(d: &Document, preview: Option<&[u8]>) -> Result<Vec<u8>> {
 pub fn with_document_extension(path: &str) -> String {
     let p = std::path::Path::new(path);
     let ext = p.extension().and_then(std::ffi::OsStr::to_str);
-    if p.file_name().is_none() || ext.is_some_and(|e| e.eq_ignore_ascii_case(designcraft_format::EXTENSION)) {
+    if p.file_name().is_none() || ext.is_some_and(|e| craft_file_formats::from_extension(e) == Some(craft_file_formats::Format::DesignCraft)) {
         return path.to_string();
     }
     format!("{path}.{}", designcraft_format::EXTENSION)
@@ -32,7 +32,7 @@ pub fn with_document_extension(path: &str) -> String {
 /// that kept it would name the file `Brochure.designcraft.designcraft`. A bare `.designcraft` stays.
 pub(super) fn without_native_extension(name: &str) -> &str {
     match name.rsplit_once('.') {
-        Some((stem, ext)) if !stem.is_empty() && ext.eq_ignore_ascii_case(designcraft_format::EXTENSION) => stem,
+        Some((stem, ext)) if !stem.is_empty() && craft_file_formats::from_extension(ext) == Some(craft_file_formats::Format::DesignCraft) => stem,
         _ => name,
     }
 }
diff --git a/crates/ui-egui/Cargo.toml b/crates/ui-egui/Cargo.toml
index 6b08420a9..143dfebfd 100644
--- a/crates/ui-egui/Cargo.toml
+++ b/crates/ui-egui/Cargo.toml
@@ -13,6 +13,7 @@ workspace = true
 craft-ui = { workspace = true, features = ["native-windows"] }
 craft-window = { workspace = true }
 craft-keymap = { workspace = true }
+craft-file-formats = { workspace = true }
 designcraft-geom = { workspace = true }
 designcraft-color = { workspace = true }
 designcraft-doc = { workspace = true }
diff --git a/crates/ui-egui/src/app/files.rs b/crates/ui-egui/src/app/files.rs
index 069515394..61f0f9bbe 100644
--- a/crates/ui-egui/src/app/files.rs
+++ b/crates/ui-egui/src/app/files.rs
@@ -24,7 +24,7 @@ impl DesignApp {
     /// Open (`open`) or place (`place`) the file at `path`, chosen in a dialog or passed by a script.
     pub(crate) fn open_picked(&mut self, purpose: &str, path: String) -> Result<Value, String> {
         // Image Import Options: a multi-page PDF asks which page.
-        if purpose == "place" && path.to_ascii_lowercase().ends_with(".pdf") {
+        if purpose == "place" && craft_file_formats::detect(&path, &[]) == Some(craft_file_formats::Format::Pdf) {
             let target = self.session.active().map(|d| d.uid);
             let pages = self.services.read.as_mut().and_then(|r| r(&path).ok()).and_then(|b| designcraft_render::pdf_page_count(&b)).unwrap_or(1);
             if pages > 1 {
@@ -126,7 +126,7 @@ impl DesignApp {
     }
 
     fn import_file(&mut self, file: ImportedFile) -> Result<Value, String> {
-        let lower = file.name.to_ascii_lowercase();
+        let format = craft_file_formats::detect(&file.name, &file.bytes);
         if let Some(kind) = file.request.purpose.strip_prefix("styles") {
             self.activate_import_target(&file.request)?;
             let mut params = json!({"name": file.name, "base64": designcraft_engine::cmd::base64_encode(&file.bytes)});
@@ -140,11 +140,11 @@ impl DesignApp {
         let layout = opens_as_document(&file.name)
             || (std::path::Path::new(&file.name).extension().is_none() && designcraft_engine::cmd::is_document(&file.bytes));
         let place =
-            file.request.purpose == "place" || (matches!(file.request.purpose.as_str(), "drop" | "open") && !layout && !lower.ends_with(".ase"));
-        if place || lower.ends_with(".ase") || file.request.purpose == "swatches" {
+            file.request.purpose == "place" || (matches!(file.request.purpose.as_str(), "drop" | "open") && !layout && format != Some(craft_file_formats::Format::Ase));
+        if place || format == Some(craft_file_formats::Format::Ase) || file.request.purpose == "swatches" {
             self.activate_import_target(&file.request)?;
         }
-        if place && lower.ends_with(".pdf") {
+        if place && craft_file_formats::detect(&file.name, &file.bytes) == Some(craft_file_formats::Format::Pdf) {
             let pages = designcraft_render::pdf_page_count(&file.bytes).unwrap_or(1);
             if pages > 1 {
                 self.ui.dialog =
@@ -154,7 +154,7 @@ impl DesignApp {
             }
         }
         let b64 = designcraft_engine::cmd::base64_encode(&file.bytes);
-        if lower.ends_with(".ase") || file.request.purpose == "swatches" {
+        if format == Some(craft_file_formats::Format::Ase) || file.request.purpose == "swatches" {
             self.run("swatch.load", json!({"base64": b64}))
         } else if file.request.purpose == "place" {
             self.place_file(json!({"name": file.name, "base64": b64}))
@@ -198,7 +198,7 @@ impl DesignApp {
     /// the pointer when there is none, and clears the flag, so the files after it land at the
     /// pointer instead of replacing that graphic.
     pub(crate) fn place_dropped(&mut self, path: &str, pointer: Option<egui::Pos2>, frame_free: &mut bool) -> Result<Value, String> {
-        if path.to_ascii_lowercase().ends_with(".ase") {
+        if craft_file_formats::detect(path, &[]) == Some(craft_file_formats::Format::Ase) {
             return self.run("swatch.load", json!({"path": path}));
         }
         let document = opens_as_document(path)
@@ -318,8 +318,10 @@ impl DesignApp {
 /// Files that open as documents (when dropped or picked) rather than being placed: DesignCraft,
 /// IDML, and InDesign documents and templates (converted to IDML on open).
 pub fn opens_as_document(name: &str) -> bool {
-    let n = name.to_ascii_lowercase();
-    [".designcraft", ".idml", ".indd", ".indt"].iter().any(|ext| n.ends_with(ext))
+    matches!(
+        craft_file_formats::detect(name, &[]),
+        Some(craft_file_formats::Format::DesignCraft | craft_file_formats::Format::Idml | craft_file_formats::Format::Indd)
+    )
 }
 
 #[cfg(test)]
diff --git a/crates/ui-egui/src/menus/export.rs b/crates/ui-egui/src/menus/export.rs
index 2c1946d4f..a80a55fc0 100644
--- a/crates/ui-egui/src/menus/export.rs
+++ b/crates/ui-egui/src/menus/export.rs
@@ -92,7 +92,7 @@ pub(super) fn export_bytes(app: &mut DesignApp, p: &Value, ext: &str, cmd: &str)
         _ => json!({}),
     };
     if cmd == "file.exportText" {
-        let txt = path.to_ascii_lowercase().ends_with(".txt");
+        let txt = craft_file_formats::detect(&path, &[]) == Some(craft_file_formats::Format::PlainText);
         params["format"] = json!(if txt { "txt" } else { "rtf" });
     }
     let r = app.run(cmd, params)?;
diff --git a/crates/ui-egui/src/menus/run.rs b/crates/ui-egui/src/menus/run.rs
index 731efb570..054bd8060 100644
--- a/crates/ui-egui/src/menus/run.rs
+++ b/crates/ui-egui/src/menus/run.rs
@@ -142,8 +142,7 @@ fn run_ui_part1(app: &mut DesignApp, id: &str, p: &Value) -> Option<Result<Value
         "app.placeWithOptions" => {
             // Word/RTF Import Options: style mapping and conflicts before the text lands.
             let Some(path) = p.get("path").and_then(Value::as_str) else { return Some(rerun_with_path(app, "place", id, p, "path")) };
-            let l = path.to_lowercase();
-            if !(l.ends_with(".docx") || l.ends_with(".rtf")) {
+            if !matches!(craft_file_formats::detect(path, &[]), Some(craft_file_formats::Format::Docx | craft_file_formats::Format::Rtf)) {
                 return Some(app.place_file(json!({"path": path})));
             }
             let info = match app.run("place.styles", json!({"path": path})) {