diff --git a/Cargo.lock b/Cargo.lock
index b725a937..a5c80e6f 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -293,7 +293,7 @@ dependencies = [
 ]
 
 [[package]]
-name = "kdtree-tester"
+name = "kdtree-tester-cli"
 version = "0.1.0"
 dependencies = [
  "clap",
diff --git a/Cargo.toml b/Cargo.toml
index e5129680..864e1e75 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,5 +1,5 @@
 [workspace]
-members = ["geometry", "kdtree", "kdtree-cli", "kdtree-tester", "pathtracer-cli", "pathtracer-gui", "raytracer-cli", "scene", "tracing", "wavefront", "wavefront-cli"]
+members = ["geometry", "kdtree", "kdtree-cli", "kdtree-tester-cli", "pathtracer-cli", "pathtracer-gui", "raytracer-cli", "scene", "tracing", "wavefront", "wavefront-cli"]
 resolver = "2"
 
 [profile.release]
diff --git a/kdtree-tester/Cargo.toml b/kdtree-tester-cli/Cargo.toml
similarity index 95%
rename from kdtree-tester/Cargo.toml
rename to kdtree-tester-cli/Cargo.toml
index 0670afac..54428ad6 100644
--- a/kdtree-tester/Cargo.toml
+++ b/kdtree-tester-cli/Cargo.toml
@@ -1,5 +1,5 @@
 [package]
-name = "kdtree-tester"
+name = "kdtree-tester-cli"
 version = "0.1.0"
 edition = "2021"
 
diff --git a/kdtree-tester/src/checked_intersection.rs b/kdtree-tester-cli/src/checked_intersection.rs
similarity index 100%
rename from kdtree-tester/src/checked_intersection.rs
rename to kdtree-tester-cli/src/checked_intersection.rs
diff --git a/kdtree-tester/src/lib.rs b/kdtree-tester-cli/src/lib.rs
similarity index 100%
rename from kdtree-tester/src/lib.rs
rename to kdtree-tester-cli/src/lib.rs
diff --git a/kdtree-tester-cli/src/main.rs b/kdtree-tester-cli/src/main.rs
new file mode 100644
index 00000000..eb1b4f19
--- /dev/null
+++ b/kdtree-tester-cli/src/main.rs
@@ -0,0 +1,102 @@
+use clap::{Parser, Subcommand};
+use kdtree::{sah::SahCost, MAX_DEPTH};
+use ray_tester::kdtree_ray_tester;
+use reducer::kdtree_reduce;
+use size::Size;
+
+mod checked_intersection;
+mod ray_bouncer;
+mod ray_tester;
+mod reducer;
+mod size;
+
+#[derive(Parser, Debug)]
+#[command(version, about, long_about = None)]
+struct Cli {
+    #[command(subcommand)]
+    command: Commands,
+}
+
+#[derive(Subcommand, Debug)]
+enum Commands {
+    /// Compare kdtree intersection with naive intersection
+    Test {
+        /// Wavefront OBJ input path
+        #[arg(short = 'i', long, required = true)]
+        input: std::path::PathBuf,
+
+        /// Output ray fail binary data path
+        #[arg(short = 'o', long)]
+        output: Option<std::path::PathBuf>,
+        /// Image size in pixels
+        #[arg(short, long, default_value_t = Size::new(512, 512))]
+        size: Size,
+        /// Max number of bounces to test
+        #[arg(short, long, default_value_t = 10)]
+        bounces: u32,
+
+        /// Maximum kd-tree depth
+        #[arg(long, default_value_t = MAX_DEPTH as u32)]
+        max_depth: u32,
+        /// SAH kd-tree traverse cost
+        #[arg(long, default_value_t = SahCost::default().traverse_cost)]
+        traverse_cost: f32,
+        /// SAH kd-tree intersect cost
+        #[arg(long, default_value_t = SahCost::default().intersect_cost)]
+        intersect_cost: f32,
+        /// SAH kd-tree empty factor
+        #[arg(long, default_value_t = SahCost::default().empty_factor)]
+        empty_factor: f32,
+    },
+    /// Reduce tree size for a specific intersection error
+    Reduce {
+        /// Wavefront OBJ input path
+        #[arg(short = 'i', long, required = true)]
+        input: std::path::PathBuf,
+
+        /// Output reduced kd-tree JSON data path
+        #[arg(short = 'o', long, required = true)]
+        output: std::path::PathBuf,
+
+        /// Output ray fail binary data path
+        #[arg(short = 'f', long)]
+        fail: Option<std::path::PathBuf>,
+
+        /// Seed for random generator used to shuffle input geometry
+        #[arg(short = 's', long, required = true)]
+        seed: u64,
+    },
+}
+
+fn main() {
+    let args = Cli::parse();
+    match args.command {
+        Commands::Test {
+            input,
+            output,
+            size,
+            bounces,
+            max_depth,
+            traverse_cost,
+            intersect_cost,
+            empty_factor,
+        } => kdtree_ray_tester(
+            input,
+            output,
+            size,
+            bounces,
+            max_depth,
+            SahCost {
+                traverse_cost,
+                intersect_cost,
+                empty_factor,
+            },
+        ),
+        Commands::Reduce {
+            input,
+            output,
+            fail,
+            seed,
+        } => kdtree_reduce(input, output, fail, seed),
+    }
+}
diff --git a/kdtree-tester/src/ray_bouncer.rs b/kdtree-tester-cli/src/ray_bouncer.rs
similarity index 100%
rename from kdtree-tester/src/ray_bouncer.rs
rename to kdtree-tester-cli/src/ray_bouncer.rs
diff --git a/kdtree-tester-cli/src/ray_tester.rs b/kdtree-tester-cli/src/ray_tester.rs
new file mode 100644
index 00000000..c36725e3
--- /dev/null
+++ b/kdtree-tester-cli/src/ray_tester.rs
@@ -0,0 +1,67 @@
+use kdtree::{build::build_kdtree, sah::SahCost};
+use rayon::iter::{IndexedParallelIterator, IntoParallelIterator, ParallelIterator};
+use scene::{camera::Pinhole, Scene};
+use std::{
+    fs::File,
+    io::{BufWriter, Write},
+    path::PathBuf,
+};
+
+use crate::{ray_bouncer::RayBouncer, size::Size};
+
+pub(crate) fn kdtree_ray_tester(
+    input: PathBuf,
+    output: Option<PathBuf>,
+    size: Size,
+    bounces: u32,
+    max_depth: u32,
+    sah: SahCost,
+) {
+    let scene = Scene::read_obj_file_with_print_logging(&input);
+
+    println!("Building kdtree...");
+    let kdtree = build_kdtree(&scene.geometries, max_depth, &sah);
+
+    println!("Testing up to {} rays...", size.x * size.y * bounces);
+    let camera = Pinhole::new(scene.cameras[0].clone(), size.as_uvec2());
+    let bouncer = RayBouncer {
+        scene,
+        kdtree,
+        camera,
+        size: size.as_uvec2(),
+        bounces,
+    };
+
+    let xs = 0..size.x;
+    let ys = 0..size.y;
+    let pixels = ys
+        .flat_map(|y| xs.clone().map(move |x| (x, y)))
+        .collect::<Vec<_>>();
+    let pixel_count = pixels.len();
+    let fails = pixels
+        .into_par_iter()
+        .enumerate()
+        .filter_map(|(i, pixel)| {
+            let result = bouncer.bounce_pixel(pixel);
+            if let Some(fail) = &result {
+                eprintln!(
+                    "Fail on pixel {} x {} ({} / {})",
+                    pixel.0, pixel.1, i, pixel_count
+                );
+                eprintln!("  {:?}", fail.ray);
+                eprintln!("  Expected: {:?}", fail.reference);
+                eprintln!("    Actual: {:?}", fail.kdtree);
+            }
+            result
+        })
+        .collect::<Vec<_>>();
+    println!("Found {} fails", fails.len());
+
+    if let Some(path) = output {
+        println!("Writing failed rays to {:?}...", path);
+        let mut logger = BufWriter::new(File::create(path).unwrap());
+        fails.iter().enumerate().for_each(|(i, fail)| {
+            logger.write_all(&fail.as_bytes(i as u16)).unwrap();
+        });
+    }
+}
diff --git a/kdtree-tester/src/bin/kdtree-reducer-cli.rs b/kdtree-tester-cli/src/reducer.rs
similarity index 83%
rename from kdtree-tester/src/bin/kdtree-reducer-cli.rs
rename to kdtree-tester-cli/src/reducer.rs
index 48aae323..6a2727e8 100644
--- a/kdtree-tester/src/bin/kdtree-reducer-cli.rs
+++ b/kdtree-tester-cli/src/reducer.rs
@@ -1,11 +1,10 @@
 use std::{
     fs::File,
     io::{BufReader, BufWriter, Write},
+    path::PathBuf,
     time::Instant,
 };
 
-use clap::Parser;
-use kdtree_tester::checked_intersection::CheckedIntersection;
 use rand::{rngs::SmallRng, seq::SliceRandom, SeedableRng};
 
 use geometry::{geometry::Geometry, intersection::RayIntersection, ray::Ray, triangle::Triangle};
@@ -15,6 +14,8 @@ use kdtree::{
 };
 use wavefront::obj;
 
+use crate::checked_intersection::CheckedIntersection;
+
 fn build_test_tree(geometries: &[Geometry]) -> KdNode {
     build_kdtree(geometries, MAX_DEPTH as u32, &SahCost::default())
 }
@@ -101,29 +102,7 @@ fn reduce_tree(
     (geometries, tree)
 }
 
-#[derive(Parser, Debug)]
-#[command(version, about, long_about = None)]
-struct Args {
-    /// Wavefront OBJ input path
-    #[arg(short = 'i', long, required = true)]
-    input: std::path::PathBuf,
-
-    /// Output reduced kd-tree JSON data path
-    #[arg(short = 'o', long, required = true)]
-    output: std::path::PathBuf,
-
-    /// Output ray fail binary data path
-    #[arg(short = 'f', long)]
-    fail: Option<std::path::PathBuf>,
-
-    /// Seed for random generator used to shuffle input geometry
-    #[arg(short = 's', long, required = true)]
-    seed: u64,
-}
-
-fn main() {
-    let args = Args::parse();
-
+pub(crate) fn kdtree_reduce(input: PathBuf, output: PathBuf, fail: Option<PathBuf>, seed: u64) {
     let intersection = CheckedIntersection {
         ray: Ray::new(
             [3.897963, 0.24242611, -4.203691].into(),
@@ -146,14 +125,14 @@ fn main() {
             },
         )),
     };
-    eprintln!("Seed: {}", args.seed);
+    eprintln!("Seed: {}", seed);
     eprintln!("Testing with failed intersection:");
     eprintln!("  {:?}", &intersection.ray);
     eprintln!("  Expected: {:?}", &intersection.reference);
     eprintln!("    Actual: {:?}", &intersection.kdtree);
 
-    eprintln!("Loading {}...", args.input.display());
-    let obj = obj::obj(&mut BufReader::new(File::open(&args.input).unwrap()));
+    eprintln!("Loading {}...", input.display());
+    let obj = obj::obj(&mut BufReader::new(File::open(&input).unwrap()));
     eprintln!("  Chunks: {}", obj.chunks.len());
     eprintln!("  Vertices: {}", obj.vertices.len());
     eprintln!("  Normals: {}", obj.normals.len());
@@ -182,7 +161,7 @@ fn main() {
         .collect::<Vec<_>>();
     eprintln!("  Geometries: {}", geometries.len());
 
-    if let Some(path) = args.fail {
+    if let Some(path) = fail {
         eprintln!("Writing test ray to {:?}...", path);
         let file = File::create(path).unwrap();
         let mut buf = BufWriter::new(file);
@@ -190,11 +169,11 @@ fn main() {
     }
 
     eprintln!("Reducing tree...");
-    let (geometries, tree) = reduce_tree(args.seed, intersection, geometries);
+    let (geometries, tree) = reduce_tree(seed, intersection, geometries);
 
-    eprintln!("Writing reduced tree to {:?}...", args.output);
+    eprintln!("Writing reduced tree to {:?}...", output);
     write_tree_json(
-        &mut BufWriter::new(File::create(args.output).unwrap()),
+        &mut BufWriter::new(File::create(output).unwrap()),
         &geometries,
         &tree,
     )
diff --git a/kdtree-tester-cli/src/size.rs b/kdtree-tester-cli/src/size.rs
new file mode 100644
index 00000000..11c99f1b
--- /dev/null
+++ b/kdtree-tester-cli/src/size.rs
@@ -0,0 +1,37 @@
+use std::{fmt::Display, str::FromStr};
+
+use glam::UVec2;
+
+#[derive(Clone, Copy, Debug)]
+pub(crate) struct Size {
+    pub(crate) x: u32,
+    pub(crate) y: u32,
+}
+
+impl Size {
+    pub(crate) fn new(x: u32, y: u32) -> Self {
+        Size { x, y }
+    }
+
+    pub(crate) fn as_uvec2(self) -> UVec2 {
+        UVec2::new(self.x, self.y)
+    }
+}
+
+impl FromStr for Size {
+    type Err = <u32 as FromStr>::Err;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        let pos = s.find('x').expect("Could not parse");
+        Ok(Size {
+            x: s[0..pos].parse()?,
+            y: s[pos + 1..].parse()?,
+        })
+    }
+}
+
+impl Display for Size {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}x{}", self.x, self.y)
+    }
+}
diff --git a/kdtree-tester/src/bin/kdtree-tester-cli.rs b/kdtree-tester/src/bin/kdtree-tester-cli.rs
deleted file mode 100644
index b8ffffa2..00000000
--- a/kdtree-tester/src/bin/kdtree-tester-cli.rs
+++ /dev/null
@@ -1,139 +0,0 @@
-use clap::Parser;
-use glam::UVec2;
-use kdtree::{build::build_kdtree, sah::SahCost, MAX_DEPTH};
-use kdtree_tester::ray_bouncer::RayBouncer;
-use rayon::iter::{IndexedParallelIterator, IntoParallelIterator, ParallelIterator};
-use scene::{camera::Pinhole, Scene};
-use std::{
-    fmt::Display,
-    fs::File,
-    io::{BufWriter, Write},
-    str::{self, FromStr},
-};
-
-#[derive(Clone, Copy, Debug)]
-struct Size {
-    x: u32,
-    y: u32,
-}
-
-impl Size {
-    fn new(x: u32, y: u32) -> Self {
-        Size { x, y }
-    }
-
-    fn as_uvec2(self) -> UVec2 {
-        UVec2::new(self.x, self.y)
-    }
-}
-
-impl FromStr for Size {
-    type Err = <u32 as FromStr>::Err;
-
-    fn from_str(s: &str) -> Result<Self, Self::Err> {
-        let pos = s.find('x').expect("Could not parse");
-        Ok(Size {
-            x: s[0..pos].parse()?,
-            y: s[pos + 1..].parse()?,
-        })
-    }
-}
-
-impl Display for Size {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        write!(f, "{}x{}", self.x, self.y)
-    }
-}
-
-#[derive(Parser, Debug)]
-#[command(version, about, long_about = None)]
-struct Args {
-    /// Wavefront OBJ input path
-    #[arg(short = 'i', long, required = true)]
-    input: std::path::PathBuf,
-
-    /// Output ray fail binary data path
-    #[arg(short = 'o', long)]
-    output: Option<std::path::PathBuf>,
-    /// Image size in pixels
-    #[arg(short, long, default_value_t = Size::new(512, 512))]
-    size: Size,
-    /// Max number of bounces to test
-    #[arg(short, long, default_value_t = 10)]
-    bounces: u32,
-
-    /// Maximum kd-tree depth
-    #[arg(long, default_value_t = MAX_DEPTH as u32)]
-    max_depth: u32,
-    /// SAH kd-tree traverse cost
-    #[arg(long, default_value_t = SahCost::default().traverse_cost)]
-    traverse_cost: f32,
-    /// SAH kd-tree intersect cost
-    #[arg(long, default_value_t = SahCost::default().intersect_cost)]
-    intersect_cost: f32,
-    /// SAH kd-tree empty factor
-    #[arg(long, default_value_t = SahCost::default().empty_factor)]
-    empty_factor: f32,
-}
-
-fn main() {
-    let args = Args::parse();
-    let scene = Scene::read_obj_file_with_print_logging(&args.input);
-
-    println!("Building kdtree...");
-    let kdtree = build_kdtree(
-        &scene.geometries,
-        args.max_depth,
-        &SahCost {
-            traverse_cost: args.traverse_cost,
-            intersect_cost: args.intersect_cost,
-            empty_factor: args.empty_factor,
-        },
-    );
-
-    println!(
-        "Testing up to {} rays...",
-        args.size.x * args.size.y * args.bounces
-    );
-    let camera = Pinhole::new(scene.cameras[0].clone(), args.size.as_uvec2());
-    let bouncer = RayBouncer {
-        scene,
-        kdtree,
-        camera,
-        size: args.size.as_uvec2(),
-        bounces: args.bounces,
-    };
-
-    let xs = 0..args.size.x;
-    let ys = 0..args.size.y;
-    let pixels = ys
-        .flat_map(|y| xs.clone().map(move |x| (x, y)))
-        .collect::<Vec<_>>();
-    let pixel_count = pixels.len();
-    let fails = pixels
-        .into_par_iter()
-        .enumerate()
-        .filter_map(|(i, pixel)| {
-            let result = bouncer.bounce_pixel(pixel);
-            if let Some(fail) = &result {
-                eprintln!(
-                    "Fail on pixel {} x {} ({} / {})",
-                    pixel.0, pixel.1, i, pixel_count
-                );
-                eprintln!("  {:?}", fail.ray);
-                eprintln!("  Expected: {:?}", fail.reference);
-                eprintln!("    Actual: {:?}", fail.kdtree);
-            }
-            result
-        })
-        .collect::<Vec<_>>();
-    println!("Found {} fails", fails.len());
-
-    if let Some(path) = args.output {
-        println!("Writing failed rays to {:?}...", path);
-        let mut logger = BufWriter::new(File::create(path).unwrap());
-        fails.iter().enumerate().for_each(|(i, fail)| {
-            logger.write_all(&fail.as_bytes(i as u16)).unwrap();
-        });
-    }
-}