diff --git a/qoi-bench/Cargo.toml b/qoi-bench/Cargo.toml
new file mode 100644
index 0000000..d61a5e9
--- /dev/null
+++ b/qoi-bench/Cargo.toml
@@ -0,0 +1,17 @@
+[package]
+name = "qoi-bench"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+# internal
+qoi-fast = { path = ".." }
+# external
+anyhow = "1.0"
+libc = "0.2"
+png = "0.17"
+structopt = "0.3"
+walkdir = "2.3"
+
+[build-dependencies]
+cc = "1.0"
diff --git a/qoi-bench/build.rs b/qoi-bench/build.rs
new file mode 100644
index 0000000..f69cb6a
--- /dev/null
+++ b/qoi-bench/build.rs
@@ -0,0 +1,18 @@
+use std::env;
+use std::fs;
+use std::path::PathBuf;
+
+fn main() {
+    let out_dir = PathBuf::from(env::var("OUT_DIR").unwrap());
+    let out_src = out_dir.join("qoi.c");
+    fs::write(&out_src, "#include \"qoi.h\"\n").unwrap();
+
+    cc::Build::new()
+        .file(&out_src)
+        .include("../ext/qoi")
+        .define("QOI_NO_STDIO", None)
+        .define("QOI_IMPLEMENTATION", None)
+        .flag("-Wno-unsequenced")
+        .opt_level(3)
+        .compile("qoi");
+}
diff --git a/qoi-bench/src/main.rs b/qoi-bench/src/main.rs
new file mode 100644
index 0000000..1789711
--- /dev/null
+++ b/qoi-bench/src/main.rs
@@ -0,0 +1,342 @@
+use std::fs::{self, File};
+use std::path::{Path, PathBuf};
+use std::ptr;
+use std::time::{Duration, Instant};
+
+use anyhow::{bail, ensure, Context, Result};
+use libc::{c_int, c_void};
+use structopt::StructOpt;
+use walkdir::{DirEntry, WalkDir};
+
+#[derive(Debug, Copy, Clone, Default)]
+#[repr(C)]
+#[allow(non_camel_case_types)]
+struct qoi_desc {
+    width: u32,
+    height: u32,
+    channels: u8,
+    colorspace: u8,
+}
+
+extern "C" {
+    fn qoi_encode(data: *const c_void, desc: *const qoi_desc, out_len: *mut c_int) -> *mut c_void;
+    fn qoi_decode(
+        data: *const c_void, size: c_int, desc: *mut qoi_desc, channels: c_int,
+    ) -> *mut c_void;
+}
+
+fn black_box<T>(dummy: T) -> T {
+    unsafe {
+        let ret = core::ptr::read_volatile(&dummy);
+        core::mem::forget(dummy);
+        ret
+    }
+}
+
+fn timeit<T>(func: impl Fn() -> T) -> (T, Duration) {
+    let t0 = Instant::now();
+    let out = func();
+    let t1 = Instant::now();
+    (black_box(out), t1 - t0)
+}
+
+fn mean(v: &[f64]) -> f64 {
+    v.iter().sum::<f64>() / v.len() as f64
+}
+
+fn find_pngs(paths: &[PathBuf]) -> Result<Vec<PathBuf>> {
+    let is_png_file = |path: &PathBuf| {
+        path.is_file()
+            && path.extension().unwrap_or_default().to_string_lossy().to_ascii_lowercase() == "png"
+    };
+
+    let mut out = vec![];
+    for path in paths {
+        if is_png_file(path) {
+            out.push(path.clone());
+        } else if path.is_dir() {
+            out.extend(
+                WalkDir::new(path)
+                    .follow_links(true)
+                    .into_iter()
+                    .filter_map(Result::ok)
+                    .map(DirEntry::into_path)
+                    .filter(is_png_file),
+            )
+        } else {
+            bail!("path doesn't exist: {}", path.to_string_lossy());
+        }
+    }
+    Ok(out)
+}
+
+struct Image {
+    pub width: u32,
+    pub height: u32,
+    pub channels: u8,
+    pub data: Vec<u8>,
+}
+
+impl Image {
+    pub const fn n_pixels(&self) -> usize {
+        (self.width as usize) * (self.height as usize)
+    }
+}
+
+fn read_png(filename: &Path) -> Result<Image> {
+    let decoder = png::Decoder::new(File::open(filename)?);
+    let mut reader = decoder.read_info()?;
+    let mut buf = vec![0; reader.output_buffer_size()];
+    let info = reader.next_frame(&mut buf)?;
+    let bytes = &buf[..info.buffer_size()];
+    Ok(Image {
+        width: info.width,
+        height: info.height,
+        channels: info.color_type.samples() as u8,
+        data: bytes.to_vec(),
+    })
+}
+
+trait Codec {
+    fn name() -> &'static str;
+
+    fn encode(img: &Image) -> Result<Vec<u8>>;
+
+    fn encode_bench(img: &Image) -> Result<()> {
+        let _ = black_box(Self::encode(img)?);
+        Ok(())
+    }
+
+    fn decode(data: &[u8], img: &Image) -> Result<Vec<u8>>;
+
+    fn decode_bench(data: &[u8], img: &Image) -> Result<()> {
+        let _ = black_box(Self::decode(data, img)?);
+        Ok(())
+    }
+}
+
+struct CodecQoiFast;
+
+impl Codec for CodecQoiFast {
+    fn name() -> &'static str {
+        "qoi-fast"
+    }
+
+    fn encode(img: &Image) -> Result<Vec<u8>> {
+        Ok(qoi_fast::qoi_encode_to_vec(&img.data, img.width, img.height, img.channels, 0)?)
+    }
+
+    fn decode(data: &[u8], img: &Image) -> Result<Vec<u8>> {
+        Ok(qoi_fast::qoi_decode_to_vec(data, img.channels)?.1)
+    }
+}
+
+struct CodecQoiFastCanonical;
+
+impl Codec for CodecQoiFastCanonical {
+    fn name() -> &'static str {
+        "qoi-fast(c)"
+    }
+
+    fn encode(img: &Image) -> Result<Vec<u8>> {
+        Ok(qoi_fast::canonical::qoi_encode_to_vec(
+            &img.data,
+            img.width,
+            img.height,
+            img.channels,
+            0,
+        )?)
+    }
+
+    fn decode(data: &[u8], img: &Image) -> Result<Vec<u8>> {
+        Ok(qoi_fast::qoi_decode_to_vec(data, img.channels)?.1)
+    }
+}
+
+struct CodecQoiC;
+
+impl CodecQoiC {
+    unsafe fn qoi_encode(img: &Image) -> Result<(*mut u8, usize)> {
+        let desc = qoi_desc {
+            width: img.width,
+            height: img.height,
+            channels: img.channels,
+            colorspace: 0,
+        };
+        let mut out_len: c_int = 0;
+        let ptr =
+            qoi_encode(img.data.as_ptr() as *const _, &desc as *const _, &mut out_len as *mut _);
+        ensure!(!ptr.is_null(), "error encoding with qoi-c");
+        Ok((ptr as _, out_len as _))
+    }
+
+    unsafe fn qoi_decode(data: &[u8], img: &Image) -> Result<(*mut u8, qoi_desc)> {
+        let mut desc = qoi_desc::default();
+        let ptr =
+            qoi_decode(data.as_ptr() as _, data.len() as _, &mut desc as *mut _, img.channels as _);
+        ensure!(!ptr.is_null(), "error decoding with qoi-c");
+        Ok((ptr as _, desc))
+    }
+}
+
+impl Codec for CodecQoiC {
+    fn name() -> &'static str {
+        "qoi-c"
+    }
+
+    fn encode(img: &Image) -> Result<Vec<u8>> {
+        unsafe {
+            let (ptr, len) = Self::qoi_encode(img)?;
+            let mut vec = Vec::with_capacity(len);
+            vec.set_len(len);
+            ptr::copy_nonoverlapping(ptr, vec.as_mut_ptr(), len);
+            libc::free(ptr as _);
+            Ok(vec)
+        }
+    }
+
+    fn encode_bench(img: &Image) -> Result<()> {
+        unsafe {
+            let (ptr, _) = Self::qoi_encode(img)?;
+            libc::free(ptr as _);
+            Ok(())
+        }
+    }
+
+    fn decode(data: &[u8], img: &Image) -> Result<Vec<u8>> {
+        unsafe {
+            let (ptr, desc) = Self::qoi_decode(data, img)?;
+            let len = desc.width as usize * desc.height as usize * desc.channels as usize;
+            let mut vec = Vec::with_capacity(len);
+            vec.set_len(len);
+            ptr::copy_nonoverlapping(ptr, vec.as_mut_ptr(), len);
+            libc::free(ptr as _);
+            Ok(vec)
+        }
+    }
+
+    fn decode_bench(data: &[u8], img: &Image) -> Result<()> {
+        unsafe {
+            let (ptr, _) = Self::qoi_decode(data, img)?;
+            libc::free(ptr as _);
+            Ok(())
+        }
+    }
+}
+
+struct BenchResult {
+    pub codec: String,
+    pub encode_sec: Vec<f64>,
+    pub decode_sec: Vec<f64>,
+    pub size_encoded: usize,
+}
+
+struct ImageBench {
+    img: Image,
+    sec_allowed: f64,
+    results: Vec<BenchResult>,
+}
+
+impl ImageBench {
+    pub fn new(img: Image, sec_allowed: f64) -> Self {
+        Self { img, sec_allowed, results: vec![] }
+    }
+
+    pub fn run<C: Codec>(&mut self) -> Result<()> {
+        let (encoded, t_encode) = timeit(|| C::encode(&self.img));
+        let encoded = encoded?;
+        let (decoded, t_decode) = timeit(|| C::decode(&encoded, &self.img));
+        let decoded = decoded?;
+        ensure!(decoded.as_slice() == self.img.data.as_slice(), "decoded data doesn't roundtrip");
+
+        let n_encode = (self.sec_allowed / 2. / t_encode.as_secs_f64()).max(2.).ceil() as usize;
+        let mut encode_tm = Vec::with_capacity(n_encode);
+        for _ in 0..n_encode {
+            encode_tm.push(timeit(|| C::encode_bench(&self.img)).1);
+        }
+        encode_tm.sort_unstable();
+        let encode_sec = encode_tm.iter().map(Duration::as_secs_f64).collect();
+
+        let n_decode = (self.sec_allowed / 2. / t_decode.as_secs_f64()).max(2.).ceil() as usize;
+        let mut decode_tm = Vec::with_capacity(n_decode);
+        for _ in 0..n_decode {
+            decode_tm.push(timeit(|| C::decode_bench(&encoded, &self.img)).1);
+        }
+        decode_tm.sort_unstable();
+        let decode_sec = decode_tm.iter().map(Duration::as_secs_f64).collect();
+
+        self.results.push(BenchResult {
+            codec: C::name().to_owned(),
+            encode_sec,
+            decode_sec,
+            size_encoded: encoded.len(),
+        });
+        Ok(())
+    }
+
+    pub fn report(&self, use_median: bool) {
+        let (w_name, w_col) = (11, 13);
+        print!("{:<w$}", "codec", w = w_name);
+        print!("{:>w$}", "decode:ms", w = w_col);
+        print!("{:>w$}", "encode:ms", w = w_col);
+        print!("{:>w$}", "decode:mp/s", w = w_col);
+        print!("{:>w$}", "encode:mp/s", w = w_col);
+        print!("{:>w$}", "compression", w = w_col);
+        print!("{:>w$}", "output:kb", w = w_col);
+        println!();
+        for r in &self.results {
+            let (decode_sec, encode_sec) = if use_median {
+                (r.decode_sec[r.decode_sec.len() / 2], r.encode_sec[r.encode_sec.len() / 2])
+            } else {
+                (mean(&r.decode_sec), mean(&r.encode_sec))
+            };
+            let mpixels = self.img.n_pixels() as f64 / 1e6;
+            let (decode_mpps, encode_mpps) = (mpixels / decode_sec, mpixels / encode_sec);
+            let comp_ratio_pct = r.size_encoded as f64 / self.img.data.len() as f64 * 1e2;
+            let size_kb = r.size_encoded as f64 / 1024.;
+
+            print!("{:<w$}", r.codec, w = w_name);
+            print!("{:>w$.2}", decode_sec * 1e3, w = w_col);
+            print!("{:>w$.2}", encode_sec * 1e3, w = w_col);
+            print!("{:>w$.1}", decode_mpps, w = w_col);
+            print!("{:>w$.1}", encode_mpps, w = w_col);
+            print!("{:>w$.2}%", comp_ratio_pct, w = w_col - 1);
+            print!("{:>w$.1}", size_kb, w = w_col);
+            println!();
+        }
+    }
+}
+
+fn bench_png(filename: &Path) -> Result<()> {
+    let f = filename.to_string_lossy();
+    let img = read_png(filename).context(format!("error reading PNG file: {}", f))?;
+    let size_kb = fs::metadata(filename)?.len() / 1024;
+    let mpixels = img.n_pixels() as f64 / 1e6;
+    println!(
+        "{} ({}x{}:{}, {} KB, {:.1}MP)",
+        f, img.width, img.height, img.channels, size_kb, mpixels
+    );
+    let mut bench = ImageBench::new(img, 5.);
+    bench.run::<CodecQoiC>()?;
+    bench.run::<CodecQoiFast>()?;
+    bench.run::<CodecQoiFastCanonical>()?;
+    bench.report(true);
+    Ok(())
+}
+
+#[derive(Debug, StructOpt)]
+struct Args {
+    #[structopt(parse(from_os_str))]
+    paths: Vec<PathBuf>,
+}
+
+fn main() -> Result<()> {
+    let args = <Args as StructOpt>::from_args();
+    ensure!(!args.paths.is_empty(), "no input paths given");
+    let files = find_pngs(&args.paths)?;
+    ensure!(!files.is_empty(), "no PNG files found in given paths");
+    for file in &files {
+        bench_png(file)?;
+    }
+    Ok(())
+}
diff --git a/qoi-bench/src/qoi.c b/qoi-bench/src/qoi.c
new file mode 100644
index 0000000..2027fd9
--- /dev/null
+++ b/qoi-bench/src/qoi.c
@@ -0,0 +1 @@
+#include "qoi.h"