diff --git a/CHANGELOG.md b/CHANGELOG.md
index e5ab89e9..d590f662 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,24 @@ The `gltf` crate adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ## Unreleased
 
+## [1.4.0] - 2023-12-17
+
+### Added
+
+- New API for reading arbitary extension data.
+- Interval improvements to prevent panics on 32 bit systems when loading large glTF files.
+
+### Changed
+
+- Offsets and sizes in the `gltf-json` crate have been widened to 64 bits.
+- Loading glTF on a 32 bit system containing offsets or sizes larger than `u32` will
+  result in a validation error.
+
+### Fixed
+
+- `Gltf::from_reader` no longer winds the reader back to offset zero.
+- Broken link in `Material::unlit` documentation.
+
 ## [1.3.0] - 2023-08-21
 
 ### Added
diff --git a/Cargo.toml b/Cargo.toml
index ef385f38..96212f03 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "gltf"
-version = "1.3.0"
+version = "1.4.0"
 authors = ["David Harvey-Macaulay <alteous@outlook.com>"]
 description = "glTF 2.0 loader"
 documentation = "https://docs.rs/gltf"
@@ -25,7 +25,7 @@ approx = "0.5"
 [dependencies]
 base64 = { optional = true, version = "0.13" }
 byteorder = "1.3"
-gltf-json = { path = "gltf-json", version = "1.3.0" }
+gltf-json = { path = "gltf-json", version = "1.4.0" }
 lazy_static = "1"
 urlencoding = { optional = true, version = "2.1" }
 serde_json = { features = ["raw_value"], version = "1.0" }
diff --git a/gltf-derive/Cargo.toml b/gltf-derive/Cargo.toml
index c4808203..78c1d97a 100644
--- a/gltf-derive/Cargo.toml
+++ b/gltf-derive/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "gltf-derive"
-version = "1.3.0"
+version = "1.4.0"
 authors = ["David Harvey-Macaulay <alteous@outlook.com>"]
 description = "Internal macros for the gltf crate"
 repository = "https://github.com/gltf-rs/gltf"
diff --git a/gltf-json/Cargo.toml b/gltf-json/Cargo.toml
index 24895bea..2511ac3d 100644
--- a/gltf-json/Cargo.toml
+++ b/gltf-json/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "gltf-json"
-version = "1.3.0"
+version = "1.4.0"
 authors = ["David Harvey-Macaulay <alteous@outlook.com>"]
 description = "JSON parsing for the gltf crate"
 repository = "https://github.com/gltf-rs/gltf"
@@ -9,7 +9,7 @@ edition = "2021"
 rust-version = "1.61"
 
 [dependencies]
-gltf-derive = { path = "../gltf-derive", version = "1.3.0" }
+gltf-derive = { path = "../gltf-derive", version = "1.4.0" }
 serde = "1.0"
 serde_derive = "1.0"
 serde_json = { features = ["raw_value"], version = "1.0" }
diff --git a/src/accessor/mod.rs b/src/accessor/mod.rs
index be04545d..a932658f 100644
--- a/src/accessor/mod.rs
+++ b/src/accessor/mod.rs
@@ -140,7 +140,7 @@ impl<'a> Accessor<'a> {
         self.json.component_type.unwrap().0
     }
 
-    /// Returns the extension values map
+    /// Returns extension data unknown to this crate version.
     #[cfg(feature = "extensions")]
     #[cfg_attr(docsrs, doc(cfg(feature = "extensions")))]
     pub fn extensions(&self) -> Option<&Map<String, Value>> {
@@ -148,7 +148,7 @@ impl<'a> Accessor<'a> {
         Some(&ext.others)
     }
 
-    /// Return a value for a given extension name
+    /// Queries extension data unknown to this crate version.
     #[cfg(feature = "extensions")]
     #[cfg_attr(docsrs, doc(cfg(feature = "extensions")))]
     pub fn extension_value(&self, ext_name: &str) -> Option<&Value> {
diff --git a/src/animation/mod.rs b/src/animation/mod.rs
index 29d8ae05..eecad625 100644
--- a/src/animation/mod.rs
+++ b/src/animation/mod.rs
@@ -113,7 +113,7 @@ impl<'a> Animation<'a> {
         }
     }
 
-    /// Returns the extension values map
+    /// Returns extension data unknown to this crate version.
     #[cfg(feature = "extensions")]
     #[cfg_attr(docsrs, doc(cfg(feature = "extensions")))]
     pub fn extensions(&self) -> Option<&Map<String, Value>> {
@@ -121,7 +121,7 @@ impl<'a> Animation<'a> {
         Some(&ext.others)
     }
 
-    /// Return a value for a given extension name
+    /// Queries extension data unknown to this crate version.
     #[cfg(feature = "extensions")]
     #[cfg_attr(docsrs, doc(cfg(feature = "extensions")))]
     pub fn extension_value(&self, ext_name: &str) -> Option<&Value> {
diff --git a/src/buffer.rs b/src/buffer.rs
index e25be67e..492fa88c 100644
--- a/src/buffer.rs
+++ b/src/buffer.rs
@@ -103,7 +103,7 @@ impl<'a> Buffer<'a> {
         self.json.name.as_deref()
     }
 
-    /// Returns the extension values map
+    /// Returns extension data unknown to this crate version.
     #[cfg(feature = "extensions")]
     #[cfg_attr(docsrs, doc(cfg(feature = "extensions")))]
     pub fn extensions(&self) -> Option<&Map<String, Value>> {
@@ -111,7 +111,7 @@ impl<'a> Buffer<'a> {
         Some(&ext.others)
     }
 
-    /// Return a value for a given extension name
+    /// Queries extension data unknown to this crate version.
     #[cfg(feature = "extensions")]
     #[cfg_attr(docsrs, doc(cfg(feature = "extensions")))]
     pub fn extension_value(&self, ext_name: &str) -> Option<&Value> {
@@ -186,7 +186,7 @@ impl<'a> View<'a> {
         self.json.target.map(|target| target.unwrap())
     }
 
-    /// Returns the extension values map
+    /// Returns extension data unknown to this crate version.
     #[cfg(feature = "extensions")]
     #[cfg_attr(docsrs, doc(cfg(feature = "extensions")))]
     pub fn extensions(&self) -> Option<&Map<String, Value>> {
@@ -194,7 +194,7 @@ impl<'a> View<'a> {
         Some(&ext.others)
     }
 
-    /// Return a value for a given extension name
+    /// Queries extension data unknown to this crate version.
     #[cfg(feature = "extensions")]
     #[cfg_attr(docsrs, doc(cfg(feature = "extensions")))]
     pub fn extension_value(&self, ext_name: &str) -> Option<&Value> {
diff --git a/src/camera.rs b/src/camera.rs
index 1feb212e..a4ce37b0 100644
--- a/src/camera.rs
+++ b/src/camera.rs
@@ -89,7 +89,7 @@ impl<'a> Camera<'a> {
         }
     }
 
-    /// Returns the extension values map
+    /// Returns extension data unknown to this crate version.
     #[cfg(feature = "extensions")]
     #[cfg_attr(docsrs, doc(cfg(feature = "extensions")))]
     pub fn extensions(&self) -> Option<&Map<String, Value>> {
@@ -97,7 +97,7 @@ impl<'a> Camera<'a> {
         Some(&ext.others)
     }
 
-    /// Return a value for a given extension name
+    /// Queries extension data unknown to this crate version.
     #[cfg(feature = "extensions")]
     #[cfg_attr(docsrs, doc(cfg(feature = "extensions")))]
     pub fn extension_value(&self, ext_name: &str) -> Option<&Value> {
@@ -137,7 +137,7 @@ impl<'a> Orthographic<'a> {
         self.json.znear
     }
 
-    /// Returns the extension values map
+    /// Returns extension data unknown to this crate version.
     #[cfg(feature = "extensions")]
     #[cfg_attr(docsrs, doc(cfg(feature = "extensions")))]
     pub fn extensions(&self) -> Option<&Map<String, Value>> {
@@ -145,7 +145,7 @@ impl<'a> Orthographic<'a> {
         Some(&ext.others)
     }
 
-    /// Return a value for a given extension name
+    /// Queries extension data unknown to this crate version.
     #[cfg(feature = "extensions")]
     #[cfg_attr(docsrs, doc(cfg(feature = "extensions")))]
     pub fn extension_value(&self, ext_name: &str) -> Option<&Value> {
@@ -185,7 +185,7 @@ impl<'a> Perspective<'a> {
         self.json.znear
     }
 
-    /// Returns the extension values map
+    /// Returns extension data unknown to this crate version.
     #[cfg(feature = "extensions")]
     #[cfg_attr(docsrs, doc(cfg(feature = "extensions")))]
     pub fn extensions(&self) -> Option<&Map<String, Value>> {
@@ -193,7 +193,7 @@ impl<'a> Perspective<'a> {
         Some(&ext.others)
     }
 
-    /// Return a value for a given extension name
+    /// Queries extension data unknown to this crate version.
     #[cfg(feature = "extensions")]
     #[cfg_attr(docsrs, doc(cfg(feature = "extensions")))]
     pub fn extension_value(&self, ext_name: &str) -> Option<&Value> {
diff --git a/src/image.rs b/src/image.rs
index 24e55cf9..e1904dbe 100644
--- a/src/image.rs
+++ b/src/image.rs
@@ -131,7 +131,7 @@ impl<'a> Image<'a> {
         }
     }
 
-    /// Returns the extension values map
+    /// Returns extension data unknown to this crate version.
     #[cfg(feature = "extensions")]
     #[cfg_attr(docsrs, doc(cfg(feature = "extensions")))]
     pub fn extensions(&self) -> Option<&Map<String, Value>> {
@@ -139,7 +139,7 @@ impl<'a> Image<'a> {
         Some(&ext.others)
     }
 
-    /// Return a value for a given extension name
+    /// Queries extension data unknown to this crate version.
     #[cfg(feature = "extensions")]
     #[cfg_attr(docsrs, doc(cfg(feature = "extensions")))]
     pub fn extension_value(&self, ext_name: &str) -> Option<&Value> {
diff --git a/src/lib.rs b/src/lib.rs
index 909f0af2..065d7bc9 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -446,7 +446,7 @@ impl Document {
         }
     }
 
-    /// Returns the extension values map
+    /// Returns extension data unknown to this crate version.
     #[cfg(feature = "extensions")]
     #[cfg_attr(docsrs, doc(cfg(feature = "extensions")))]
     pub fn extensions(&self) -> Option<&Map<String, Value>> {
@@ -454,7 +454,7 @@ impl Document {
         Some(&root.others)
     }
 
-    /// Return a value for a given extension name
+    /// Queries extension data unknown to this crate version.
     #[cfg(feature = "extensions")]
     #[cfg_attr(docsrs, doc(cfg(feature = "extensions")))]
     pub fn extension_value(&self, ext_name: &str) -> Option<&Value> {
diff --git a/src/material.rs b/src/material.rs
index ad382782..b0f28992 100644
--- a/src/material.rs
+++ b/src/material.rs
@@ -96,7 +96,7 @@ impl<'a> Material<'a> {
         PbrMetallicRoughness::new(self.document, &self.json.pbr_metallic_roughness)
     }
 
-    /// Returns the extension values map
+    /// Returns extension data unknown to this crate version.
     #[cfg(feature = "extensions")]
     #[cfg_attr(docsrs, doc(cfg(feature = "extensions")))]
     pub fn extensions(&self) -> Option<&Map<String, Value>> {
@@ -239,7 +239,7 @@ impl<'a> Material<'a> {
     /// Returns `true` if the [`KHR_materials_unlit`] property was specified, in which
     /// case the renderer should prefer to ignore all PBR values except `baseColor`.
     ///
-    /// [`KHR_materials_unlit`](https://github.com/KhronosGroup/glTF/tree/master/extensions/2.0/Khronos/KHR_materials_unlit#overview)
+    /// [`KHR_materials_unlit`]: https://github.com/KhronosGroup/glTF/tree/master/extensions/2.0/Khronos/KHR_materials_unlit#overview
     #[cfg(feature = "KHR_materials_unlit")]
     #[cfg_attr(docsrs, doc(cfg(feature = "KHR_materials_unlit")))]
     pub fn unlit(&self) -> bool {
@@ -320,7 +320,7 @@ impl<'a> PbrMetallicRoughness<'a> {
         })
     }
 
-    /// Returns the extension values map
+    /// Returns extension data unknown to this crate version.
     #[cfg(feature = "extensions")]
     #[cfg_attr(docsrs, doc(cfg(feature = "extensions")))]
     pub fn extensions(&self) -> Option<&Map<String, Value>> {
@@ -610,7 +610,7 @@ impl<'a> NormalTexture<'a> {
         self.texture.clone()
     }
 
-    /// Returns the extension values map
+    /// Returns extension data unknown to this crate version.
     #[cfg(feature = "extensions")]
     #[cfg_attr(docsrs, doc(cfg(feature = "extensions")))]
     pub fn extensions(&self) -> Option<&Map<String, Value>> {
@@ -665,7 +665,7 @@ impl<'a> OcclusionTexture<'a> {
         self.texture.clone()
     }
 
-    /// Returns the extension values map
+    /// Returns extension data unknown to this crate version.
     #[cfg(feature = "extensions")]
     #[cfg_attr(docsrs, doc(cfg(feature = "extensions")))]
     pub fn extensions(&self) -> Option<&Map<String, Value>> {
diff --git a/src/mesh/mod.rs b/src/mesh/mod.rs
index fe74e119..bbf6b2ff 100644
--- a/src/mesh/mod.rs
+++ b/src/mesh/mod.rs
@@ -148,7 +148,7 @@ impl<'a> Mesh<'a> {
         self.index
     }
 
-    /// Returns the extension values map
+    /// Returns extension data unknown to this crate version.
     #[cfg(feature = "extensions")]
     #[cfg_attr(docsrs, doc(cfg(feature = "extensions")))]
     pub fn extensions(&self) -> Option<&Map<String, Value>> {
@@ -156,7 +156,7 @@ impl<'a> Mesh<'a> {
         Some(&ext.others)
     }
 
-    /// Return a value for a given extension name
+    /// Queries extension data unknown to this crate version.
     #[cfg(feature = "extensions")]
     #[cfg_attr(docsrs, doc(cfg(feature = "extensions")))]
     pub fn extension_value(&self, ext_name: &str) -> Option<&Value> {
@@ -215,7 +215,7 @@ impl<'a> Primitive<'a> {
         Bounds { min, max }
     }
 
-    /// Returns the extension values map
+    /// Returns extension data unknown to this crate version.
     #[cfg(feature = "extensions")]
     #[cfg_attr(docsrs, doc(cfg(feature = "extensions")))]
     pub fn extensions(&self) -> Option<&Map<String, Value>> {
@@ -223,7 +223,7 @@ impl<'a> Primitive<'a> {
         Some(&ext.others)
     }
 
-    /// Return a value for a given extension name
+    /// Queries extension data unknown to this crate version.
     #[cfg(feature = "extensions")]
     #[cfg_attr(docsrs, doc(cfg(feature = "extensions")))]
     pub fn extension_value(&self, ext_name: &str) -> Option<&Value> {
diff --git a/src/scene/mod.rs b/src/scene/mod.rs
index 1f58ad55..71db9f91 100644
--- a/src/scene/mod.rs
+++ b/src/scene/mod.rs
@@ -145,7 +145,7 @@ impl<'a> Node<'a> {
         }
     }
 
-    /// Returns the extension values map
+    /// Returns extension data unknown to this crate version.
     #[cfg(feature = "extensions")]
     #[cfg_attr(docsrs, doc(cfg(feature = "extensions")))]
     pub fn extensions(&self) -> Option<&Map<String, Value>> {
@@ -153,7 +153,7 @@ impl<'a> Node<'a> {
         Some(&ext.others)
     }
 
-    /// Return a value for a given extension name
+    /// Queries extension data unknown to this crate version.
     #[cfg(feature = "extensions")]
     #[cfg_attr(docsrs, doc(cfg(feature = "extensions")))]
     pub fn extension_value(&self, ext_name: &str) -> Option<&Value> {
@@ -245,7 +245,7 @@ impl<'a> Scene<'a> {
         self.index
     }
 
-    /// Returns the extension values map
+    /// Returns extension data unknown to this crate version.
     #[cfg(feature = "extensions")]
     #[cfg_attr(docsrs, doc(cfg(feature = "extensions")))]
     pub fn extensions(&self) -> Option<&Map<String, Value>> {
@@ -253,7 +253,7 @@ impl<'a> Scene<'a> {
         Some(&ext.others)
     }
 
-    /// Return a value for a given extension name
+    /// Queries extension data unknown to this crate version.
     #[cfg(feature = "extensions")]
     #[cfg_attr(docsrs, doc(cfg(feature = "extensions")))]
     pub fn extension_value(&self, ext_name: &str) -> Option<&Value> {
diff --git a/src/skin/mod.rs b/src/skin/mod.rs
index 1d5708a5..0298cde9 100644
--- a/src/skin/mod.rs
+++ b/src/skin/mod.rs
@@ -46,7 +46,7 @@ impl<'a> Skin<'a> {
         self.index
     }
 
-    /// Returns the extension values map
+    /// Returns extension data unknown to this crate version.
     #[cfg(feature = "extensions")]
     #[cfg_attr(docsrs, doc(cfg(feature = "extensions")))]
     pub fn extensions(&self) -> Option<&Map<String, Value>> {
@@ -54,7 +54,7 @@ impl<'a> Skin<'a> {
         Some(&ext.others)
     }
 
-    /// Return a value for a given extension name
+    /// Queries extension data unknown to this crate version.
     #[cfg(feature = "extensions")]
     #[cfg_attr(docsrs, doc(cfg(feature = "extensions")))]
     pub fn extension_value(&self, ext_name: &str) -> Option<&Value> {
diff --git a/src/texture.rs b/src/texture.rs
index ad08a743..3aab4e07 100644
--- a/src/texture.rs
+++ b/src/texture.rs
@@ -101,7 +101,7 @@ impl<'a> Sampler<'a> {
         self.json.wrap_t.unwrap()
     }
 
-    /// Returns the extension values map
+    /// Returns extension data unknown to this crate version.
     #[cfg(feature = "extensions")]
     #[cfg_attr(docsrs, doc(cfg(feature = "extensions")))]
     pub fn extensions(&self) -> Option<&Map<String, Value>> {
@@ -109,7 +109,7 @@ impl<'a> Sampler<'a> {
         Some(&ext.others)
     }
 
-    /// Return a value for a given extension name
+    /// Queries extension data unknown to this crate version.
     #[cfg(feature = "extensions")]
     #[cfg_attr(docsrs, doc(cfg(feature = "extensions")))]
     pub fn extension_value(&self, ext_name: &str) -> Option<&Value> {
@@ -165,7 +165,7 @@ impl<'a> Texture<'a> {
             .unwrap()
     }
 
-    /// Returns the extension values map
+    /// Returns extension data unknown to this crate version.
     #[cfg(feature = "extensions")]
     #[cfg_attr(docsrs, doc(cfg(feature = "extensions")))]
     pub fn extensions(&self) -> Option<&Map<String, Value>> {
@@ -173,7 +173,7 @@ impl<'a> Texture<'a> {
         Some(&ext.others)
     }
 
-    /// Return a value for a given extension name
+    /// Queries extension data unknown to this crate version.
     #[cfg(feature = "extensions")]
     #[cfg_attr(docsrs, doc(cfg(feature = "extensions")))]
     pub fn extension_value(&self, ext_name: &str) -> Option<&Value> {
@@ -215,7 +215,7 @@ impl<'a> Info<'a> {
             .map(TextureTransform::new)
     }
 
-    /// Returns the extension values map
+    /// Returns extension data unknown to this crate version.
     #[cfg(feature = "extensions")]
     #[cfg_attr(docsrs, doc(cfg(feature = "extensions")))]
     pub fn extensions(&self) -> Option<&Map<String, Value>> {
@@ -223,7 +223,7 @@ impl<'a> Info<'a> {
         Some(&ext.others)
     }
 
-    /// Return a value for a given extension name
+    /// Queries extension data unknown to this crate version.
     #[cfg(feature = "extensions")]
     #[cfg_attr(docsrs, doc(cfg(feature = "extensions")))]
     pub fn extension_value(&self, ext_name: &str) -> Option<&Value> {