diff --git a/codecs/oxipng/.appveyor.yml b/codecs/oxipng/.appveyor.yml
new file mode 100644
index 00000000..50910bd6
--- /dev/null
+++ b/codecs/oxipng/.appveyor.yml
@@ -0,0 +1,11 @@
+install:
+  - appveyor-retry appveyor DownloadFile https://win.rustup.rs/ -FileName rustup-init.exe
+  - if not defined RUSTFLAGS rustup-init.exe -y --default-host x86_64-pc-windows-msvc --default-toolchain nightly
+  - set PATH=%PATH%;C:\Users\appveyor\.cargo\bin
+  - rustc -V
+  - cargo -V
+
+build: false
+
+test_script:
+  - cargo test --locked
diff --git a/codecs/oxipng/.cargo-ok b/codecs/oxipng/.cargo-ok
new file mode 100644
index 00000000..e69de29b
diff --git a/codecs/oxipng/.gitignore b/codecs/oxipng/.gitignore
new file mode 100644
index 00000000..4e301317
--- /dev/null
+++ b/codecs/oxipng/.gitignore
@@ -0,0 +1,6 @@
+/target
+**/*.rs.bk
+Cargo.lock
+bin/
+pkg/
+wasm-pack.log
diff --git a/codecs/oxipng/.travis.yml b/codecs/oxipng/.travis.yml
new file mode 100644
index 00000000..7a913256
--- /dev/null
+++ b/codecs/oxipng/.travis.yml
@@ -0,0 +1,69 @@
+language: rust
+sudo: false
+
+cache: cargo
+
+matrix:
+  include:
+
+  # Builds with wasm-pack.
+  - rust: beta
+    env: RUST_BACKTRACE=1
+    addons:
+      firefox: latest
+      chrome: stable
+    before_script:
+      - (test -x $HOME/.cargo/bin/cargo-install-update || cargo install cargo-update)
+      - (test -x $HOME/.cargo/bin/cargo-generate || cargo install --vers "^0.2" cargo-generate)
+      - cargo install-update -a
+      - curl https://rustwasm.github.io/wasm-pack/installer/init.sh -sSf | sh -s -- -f
+    script:
+      - cargo generate --git . --name testing
+      # Having a broken Cargo.toml (in that it has curlies in fields) anywhere
+      # in any of our parent dirs is problematic.
+      - mv Cargo.toml Cargo.toml.tmpl
+      - cd testing
+      - wasm-pack build
+      - wasm-pack test --chrome --firefox --headless
+
+  # Builds on nightly.
+  - rust: nightly
+    env: RUST_BACKTRACE=1
+    before_script:
+      - (test -x $HOME/.cargo/bin/cargo-install-update || cargo install cargo-update)
+      - (test -x $HOME/.cargo/bin/cargo-generate || cargo install --vers "^0.2" cargo-generate)
+      - cargo install-update -a
+      - rustup target add wasm32-unknown-unknown
+    script:
+      - cargo generate --git . --name testing
+      - mv Cargo.toml Cargo.toml.tmpl
+      - cd testing
+      - cargo check
+      - cargo check --target wasm32-unknown-unknown
+      - cargo check                                 --no-default-features
+      - cargo check --target wasm32-unknown-unknown --no-default-features
+      - cargo check                                 --no-default-features --features console_error_panic_hook
+      - cargo check --target wasm32-unknown-unknown --no-default-features --features console_error_panic_hook
+      - cargo check                                 --no-default-features --features "console_error_panic_hook wee_alloc"
+      - cargo check --target wasm32-unknown-unknown --no-default-features --features "console_error_panic_hook wee_alloc"
+
+  # Builds on beta.
+  - rust: beta
+    env: RUST_BACKTRACE=1
+    before_script:
+      - (test -x $HOME/.cargo/bin/cargo-install-update || cargo install cargo-update)
+      - (test -x $HOME/.cargo/bin/cargo-generate || cargo install --vers "^0.2" cargo-generate)
+      - cargo install-update -a
+      - rustup target add wasm32-unknown-unknown
+    script:
+      - cargo generate --git . --name testing
+      - mv Cargo.toml Cargo.toml.tmpl
+      - cd testing
+      - cargo check
+      - cargo check --target wasm32-unknown-unknown
+      - cargo check                                 --no-default-features
+      - cargo check --target wasm32-unknown-unknown --no-default-features
+      - cargo check                                 --no-default-features --features console_error_panic_hook
+      - cargo check --target wasm32-unknown-unknown --no-default-features --features console_error_panic_hook
+      # Note: no enabling the `wee_alloc` feature here because it requires
+      # nightly for now.
diff --git a/codecs/oxipng/Cargo.toml b/codecs/oxipng/Cargo.toml
new file mode 100644
index 00000000..ff0639de
--- /dev/null
+++ b/codecs/oxipng/Cargo.toml
@@ -0,0 +1,35 @@
+[package]
+name = "oxipng"
+version = "0.1.0"
+authors = ["Surma <surma@surma.link>"]
+
+[lib]
+crate-type = ["cdylib", "rlib"]
+
+[features]
+default = ["console_error_panic_hook"]
+
+[dependencies]
+cfg-if = "0.1.2"
+wasm-bindgen = "0.2"
+oxipng = "2.2.0"
+
+# The `console_error_panic_hook` crate provides better debugging of panics by
+# logging them with `console.error`. This is great for development, but requires
+# all the `std::fmt` and `std::panicking` infrastructure, so isn't great for
+# code size when deploying.
+console_error_panic_hook = { version = "0.1.1", optional = true }
+
+# `wee_alloc` is a tiny allocator for wasm that is only ~1K in code size
+# compared to the default allocator's ~10K. It is slower than the default
+# allocator, however.
+#
+# Unfortunately, `wee_alloc` requires nightly Rust when targeting wasm for now.
+wee_alloc = { version = "0.4.2", optional = true }
+
+[dev-dependencies]
+wasm-bindgen-test = "0.2"
+
+[profile.release]
+# Tell `rustc` to optimize for small code size.
+opt-level = "s"
diff --git a/codecs/oxipng/LICENSE_APACHE b/codecs/oxipng/LICENSE_APACHE
new file mode 100644
index 00000000..1b5ec8b7
--- /dev/null
+++ b/codecs/oxipng/LICENSE_APACHE
@@ -0,0 +1,176 @@
+                              Apache License
+                        Version 2.0, January 2004
+                     http://www.apache.org/licenses/
+
+TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+1. Definitions.
+
+   "License" shall mean the terms and conditions for use, reproduction,
+   and distribution as defined by Sections 1 through 9 of this document.
+
+   "Licensor" shall mean the copyright owner or entity authorized by
+   the copyright owner that is granting the License.
+
+   "Legal Entity" shall mean the union of the acting entity and all
+   other entities that control, are controlled by, or are under common
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+   "control" means (i) the power, direct or indirect, to cause the
+   direction or management of such entity, whether by contract or
+   otherwise, or (ii) ownership of fifty percent (50%) or more of the
+   outstanding shares, or (iii) beneficial ownership of such entity.
+
+   "You" (or "Your") shall mean an individual or Legal Entity
+   exercising permissions granted by this License.
+
+   "Source" form shall mean the preferred form for making modifications,
+   including but not limited to software source code, documentation
+   source, and configuration files.
+
+   "Object" form shall mean any form resulting from mechanical
+   transformation or translation of a Source form, including but
+   not limited to compiled object code, generated documentation,
+   and conversions to other media types.
+
+   "Work" shall mean the work of authorship, whether in Source or
+   Object form, made available under the License, as indicated by a
+   copyright notice that is included in or attached to the work
+   (an example is provided in the Appendix below).
+
+   "Derivative Works" shall mean any work, whether in Source or Object
+   form, that is based on (or derived from) the Work and for which the
+   editorial revisions, annotations, elaborations, or other modifications
+   represent, as a whole, an original work of authorship. For the purposes
+   of this License, Derivative Works shall not include works that remain
+   separable from, or merely link (or bind by name) to the interfaces of,
+   the Work and Derivative Works thereof.
+
+   "Contribution" shall mean any work of authorship, including
+   the original version of the Work and any modifications or additions
+   to that Work or Derivative Works thereof, that is intentionally
+   submitted to Licensor for inclusion in the Work by the copyright owner
+   or by an individual or Legal Entity authorized to submit on behalf of
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+   to the Licensor or its representatives, including but not limited to
+   communication on electronic mailing lists, source code control systems,
+   and issue tracking systems that are managed by, or on behalf of, the
+   Licensor for the purpose of discussing and improving the Work, but
+   excluding communication that is conspicuously marked or otherwise
+   designated in writing by the copyright owner as "Not a Contribution."
+
+   "Contributor" shall mean Licensor and any individual or Legal Entity
+   on behalf of whom a Contribution has been received by Licensor and
+   subsequently incorporated within the Work.
+
+2. Grant of Copyright License. Subject to the terms and conditions of
+   this License, each Contributor hereby grants to You a perpetual,
+   worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+   copyright license to reproduce, prepare Derivative Works of,
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+   Work and such Derivative Works in Source or Object form.
+
+3. Grant of Patent License. Subject to the terms and conditions of
+   this License, each Contributor hereby grants to You a perpetual,
+   worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+   (except as stated in this section) patent license to make, have made,
+   use, offer to sell, sell, import, and otherwise transfer the Work,
+   where such license applies only to those patent claims licensable
+   by such Contributor that are necessarily infringed by their
+   Contribution(s) alone or by combination of their Contribution(s)
+   with the Work to which such Contribution(s) was submitted. If You
+   institute patent litigation against any entity (including a
+   cross-claim or counterclaim in a lawsuit) alleging that the Work
+   or a Contribution incorporated within the Work constitutes direct
+   or contributory patent infringement, then any patent licenses
+   granted to You under this License for that Work shall terminate
+   as of the date such litigation is filed.
+
+4. Redistribution. You may reproduce and distribute copies of the
+   Work or Derivative Works thereof in any medium, with or without
+   modifications, and in Source or Object form, provided that You
+   meet the following conditions:
+
+   (a) You must give any other recipients of the Work or
+       Derivative Works a copy of this License; and
+
+   (b) You must cause any modified files to carry prominent notices
+       stating that You changed the files; and
+
+   (c) You must retain, in the Source form of any Derivative Works
+       that You distribute, all copyright, patent, trademark, and
+       attribution notices from the Source form of the Work,
+       excluding those notices that do not pertain to any part of
+       the Derivative Works; and
+
+   (d) If the Work includes a "NOTICE" text file as part of its
+       distribution, then any Derivative Works that You distribute must
+       include a readable copy of the attribution notices contained
+       within such NOTICE file, excluding those notices that do not
+       pertain to any part of the Derivative Works, in at least one
+       of the following places: within a NOTICE text file distributed
+       as part of the Derivative Works; within the Source form or
+       documentation, if provided along with the Derivative Works; or,
+       within a display generated by the Derivative Works, if and
+       wherever such third-party notices normally appear. The contents
+       of the NOTICE file are for informational purposes only and
+       do not modify the License. You may add Your own attribution
+       notices within Derivative Works that You distribute, alongside
+       or as an addendum to the NOTICE text from the Work, provided
+       that such additional attribution notices cannot be construed
+       as modifying the License.
+
+   You may add Your own copyright statement to Your modifications and
+   may provide additional or different license terms and conditions
+   for use, reproduction, or distribution of Your modifications, or
+   for any such Derivative Works as a whole, provided Your use,
+   reproduction, and distribution of the Work otherwise complies with
+   the conditions stated in this License.
+
+5. Submission of Contributions. Unless You explicitly state otherwise,
+   any Contribution intentionally submitted for inclusion in the Work
+   by You to the Licensor shall be under the terms and conditions of
+   this License, without any additional terms or conditions.
+   Notwithstanding the above, nothing herein shall supersede or modify
+   the terms of any separate license agreement you may have executed
+   with Licensor regarding such Contributions.
+
+6. Trademarks. This License does not grant permission to use the trade
+   names, trademarks, service marks, or product names of the Licensor,
+   except as required for reasonable and customary use in describing the
+   origin of the Work and reproducing the content of the NOTICE file.
+
+7. Disclaimer of Warranty. Unless required by applicable law or
+   agreed to in writing, Licensor provides the Work (and each
+   Contributor provides its Contributions) on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+   implied, including, without limitation, any warranties or conditions
+   of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+   PARTICULAR PURPOSE. You are solely responsible for determining the
+   appropriateness of using or redistributing the Work and assume any
+   risks associated with Your exercise of permissions under this License.
+
+8. Limitation of Liability. In no event and under no legal theory,
+   whether in tort (including negligence), contract, or otherwise,
+   unless required by applicable law (such as deliberate and grossly
+   negligent acts) or agreed to in writing, shall any Contributor be
+   liable to You for damages, including any direct, indirect, special,
+   incidental, or consequential damages of any character arising as a
+   result of this License or out of the use or inability to use the
+   Work (including but not limited to damages for loss of goodwill,
+   work stoppage, computer failure or malfunction, or any and all
+   other commercial damages or losses), even if such Contributor
+   has been advised of the possibility of such damages.
+
+9. Accepting Warranty or Additional Liability. While redistributing
+   the Work or Derivative Works thereof, You may choose to offer,
+   and charge a fee for, acceptance of support, warranty, indemnity,
+   or other liability obligations and/or rights consistent with this
+   License. However, in accepting such obligations, You may act only
+   on Your own behalf and on Your sole responsibility, not on behalf
+   of any other Contributor, and only if You agree to indemnify,
+   defend, and hold each Contributor harmless for any liability
+   incurred by, or claims asserted against, such Contributor by reason
+   of your accepting any such warranty or additional liability.
+
+END OF TERMS AND CONDITIONS
diff --git a/codecs/oxipng/LICENSE_MIT b/codecs/oxipng/LICENSE_MIT
new file mode 100644
index 00000000..7235cdc3
--- /dev/null
+++ b/codecs/oxipng/LICENSE_MIT
@@ -0,0 +1,25 @@
+Copyright (c) 2018 Surma <surma@surma.link>
+
+Permission is hereby granted, free of charge, to any
+person obtaining a copy of this software and associated
+documentation files (the "Software"), to deal in the
+Software without restriction, including without
+limitation the rights to use, copy, modify, merge,
+publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software
+is furnished to do so, subject to the following
+conditions:
+
+The above copyright notice and this permission notice
+shall be included in all copies or substantial portions
+of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
+ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
+TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
+PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
+SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
+IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.
diff --git a/codecs/oxipng/README.md b/codecs/oxipng/README.md
new file mode 100644
index 00000000..806d28a9
--- /dev/null
+++ b/codecs/oxipng/README.md
@@ -0,0 +1,52 @@
+# 🦀🕸️ `wasm-pack-template`
+
+A template for kick starting a Rust and WebAssembly project using
+[`wasm-pack`](https://github.com/rustwasm/wasm-pack).
+
+This template is designed for compiling Rust libraries into WebAssembly and
+publishing the resulting package to NPM.
+
+* Want to use the published NPM package in a Website? [Check out
+  `create-wasm-app`.](https://github.com/rustwasm/create-wasm-app)
+* Want to make a monorepo-style Website without publishing to NPM? Check out
+  [`rust-webpack-template`](https://github.com/rustwasm/rust-webpack-template)
+  and/or
+  [`rust-parcel-template`](https://github.com/rustwasm/rust-parcel-template).
+
+## 🔋 Batteries Included
+
+* [`wasm-bindgen`](https://github.com/rustwasm/wasm-bindgen) for communicating
+  between WebAssembly and JavaScript.
+* [`console_error_panic_hook`](https://github.com/rustwasm/console_error_panic_hook)
+  for logging panic messages to the developer console.
+* [`wee_alloc`](https://github.com/rustwasm/wee_alloc), an allocator optimized
+  for small code size.
+
+## 🚴 Usage
+
+### 🐑 Use `cargo generate` to Clone this Template
+
+[Learn more about `cargo generate` here.](https://github.com/ashleygwilliams/cargo-generate)
+
+```
+cargo generate --git https://github.com/rustwasm/wasm-pack-template.git --name my-project
+cd my-project
+```
+
+### 🛠️ Build with `wasm-pack build`
+
+```
+wasm-pack build
+```
+
+### 🔬 Test in Headless Browsers with `wasm-pack test`
+
+```
+wasm-pack test --headless --firefox
+```
+
+### 🎁 Publish to NPM with `wasm-pack publish`
+
+```
+wasm-pack publish
+```
diff --git a/codecs/oxipng/src/lib.rs b/codecs/oxipng/src/lib.rs
new file mode 100644
index 00000000..2758a22e
--- /dev/null
+++ b/codecs/oxipng/src/lib.rs
@@ -0,0 +1,33 @@
+extern crate cfg_if;
+extern crate wasm_bindgen;
+extern crate oxipng;
+
+mod utils;
+
+use cfg_if::cfg_if;
+use wasm_bindgen::prelude::*;
+
+cfg_if! {
+    // When the `wee_alloc` feature is enabled, use `wee_alloc` as the global
+    // allocator.
+    if #[cfg(feature = "wee_alloc")] {
+        extern crate wee_alloc;
+        #[global_allocator]
+        static ALLOC: wee_alloc::WeeAlloc = wee_alloc::WeeAlloc::INIT;
+    }
+}
+
+#[wasm_bindgen]
+extern {
+  #[wasm_bindgen(js_namespace = console)]
+  fn log(s: &str);
+}
+
+#[wasm_bindgen]
+pub fn compress(img: Vec<u8>, level: u8) -> Vec<u8> {
+  log(&format!("len: {}, level: {}", img.len(), level));
+  let mut options = oxipng::Options::from_preset(level);
+  options.threads = 0;
+  let result = oxipng::optimize_from_memory(img.as_slice(), &options);
+  result.unwrap()
+}
diff --git a/codecs/oxipng/src/utils.rs b/codecs/oxipng/src/utils.rs
new file mode 100644
index 00000000..2ffc954d
--- /dev/null
+++ b/codecs/oxipng/src/utils.rs
@@ -0,0 +1,17 @@
+use cfg_if::cfg_if;
+
+cfg_if! {
+    // When the `console_error_panic_hook` feature is enabled, we can call the
+    // `set_panic_hook` function at least once during initialization, and then
+    // we will get better error messages if our code ever panics.
+    //
+    // For more details see
+    // https://github.com/rustwasm/console_error_panic_hook#readme
+    if #[cfg(feature = "console_error_panic_hook")] {
+        extern crate console_error_panic_hook;
+        pub use self::console_error_panic_hook::set_once as set_panic_hook;
+    } else {
+        #[inline]
+        pub fn set_panic_hook() {}
+    }
+}
diff --git a/codecs/oxipng/tests/web.rs b/codecs/oxipng/tests/web.rs
new file mode 100644
index 00000000..de5c1daf
--- /dev/null
+++ b/codecs/oxipng/tests/web.rs
@@ -0,0 +1,13 @@
+//! Test suite for the Web and headless browsers.
+
+#![cfg(target_arch = "wasm32")]
+
+extern crate wasm_bindgen_test;
+use wasm_bindgen_test::*;
+
+wasm_bindgen_test_configure!(run_in_browser);
+
+#[wasm_bindgen_test]
+fn pass() {
+    assert_eq!(1 + 1, 2);
+}
diff --git a/src/codecs/encoders.ts b/src/codecs/encoders.ts
index ef053535..6bb84c9f 100644
--- a/src/codecs/encoders.ts
+++ b/src/codecs/encoders.ts
@@ -1,5 +1,6 @@
 import * as identity from './identity/encoder-meta';
 import * as optiPNG from './optipng/encoder-meta';
+import * as oxiPNG from './oxipng/encoder-meta';
 import * as mozJPEG from './mozjpeg/encoder-meta';
 import * as webP from './webp/encoder-meta';
 import * as browserPNG from './browser-png/encoder-meta';
@@ -18,6 +19,7 @@ export interface EncoderSupportMap {
 export type EncoderState =
   identity.EncoderState |
   optiPNG.EncoderState |
+  oxiPNG.EncoderState |
   mozJPEG.EncoderState |
   webP.EncoderState |
   browserPNG.EncoderState |
@@ -32,6 +34,7 @@ export type EncoderState =
 export type EncoderOptions =
   identity.EncodeOptions |
   optiPNG.EncodeOptions |
+  oxiPNG.EncodeOptions |
   mozJPEG.EncodeOptions |
   webP.EncodeOptions |
   browserPNG.EncodeOptions |
@@ -48,6 +51,7 @@ export type EncoderType = keyof typeof encoderMap;
 export const encoderMap = {
   [identity.type]: identity,
   [optiPNG.type]: optiPNG,
+  [oxiPNG.type]: oxiPNG,
   [mozJPEG.type]: mozJPEG,
   [webP.type]: webP,
   [browserPNG.type]: browserPNG,
diff --git a/src/codecs/optipng/encoder-meta.ts b/src/codecs/optipng/encoder-meta.ts
index 0fa86ea5..cf071528 100644
--- a/src/codecs/optipng/encoder-meta.ts
+++ b/src/codecs/optipng/encoder-meta.ts
@@ -3,7 +3,7 @@ export interface EncodeOptions {
 }
 export interface EncoderState { type: typeof type; options: EncodeOptions; }
 
-export const type = 'png';
+export const type = 'optipng';
 export const label = 'OptiPNG';
 export const mimeType = 'image/png';
 export const extension = 'png';
diff --git a/src/codecs/oxipng/encoder-meta.ts b/src/codecs/oxipng/encoder-meta.ts
new file mode 100644
index 00000000..ca586bdb
--- /dev/null
+++ b/src/codecs/oxipng/encoder-meta.ts
@@ -0,0 +1,13 @@
+export interface EncodeOptions {
+  level: number;
+}
+export interface EncoderState { type: typeof type; options: EncodeOptions; }
+
+export const type = 'oxipng';
+export const label = 'OxiPNG';
+export const mimeType = 'image/png';
+export const extension = 'png';
+
+export const defaultOptions: EncodeOptions = {
+  level: 6,
+};
diff --git a/src/codecs/oxipng/encoder.ts b/src/codecs/oxipng/encoder.ts
new file mode 100644
index 00000000..8201ff66
--- /dev/null
+++ b/src/codecs/oxipng/encoder.ts
@@ -0,0 +1,18 @@
+import * as oxipng from '../../../codecs/oxipng/pkg/oxipng_manual';
+import { EncodeOptions } from './encoder-meta';
+
+export async function compress(data: BufferSource, { level }: EncodeOptions): Promise<ArrayBuffer> {
+  let buffer: ArrayBuffer;
+
+  if (ArrayBuffer.isView(data)) {
+    buffer = data.buffer;
+  } else {
+    buffer = data;
+  }
+  debugger;
+  const resultView = await oxipng.compress(new Uint8Array(buffer), level);
+  const result = new Uint8Array(resultView);
+
+  // wasm can’t run on SharedArrayBuffers, so we hard-cast to ArrayBuffer.
+  return result.buffer as ArrayBuffer;
+}
diff --git a/src/codecs/oxipng/options.tsx b/src/codecs/oxipng/options.tsx
new file mode 100644
index 00000000..deea97f0
--- /dev/null
+++ b/src/codecs/oxipng/options.tsx
@@ -0,0 +1,42 @@
+import { h, Component } from 'preact';
+import { bind } from '../../lib/initial-util';
+import { inputFieldValueAsNumber, preventDefault } from '../../lib/util';
+import { EncodeOptions } from './encoder-meta';
+import Range from '../../components/range';
+import * as style from '../../components/Options/style.scss';
+
+type Props = {
+  options: EncodeOptions;
+  onChange(newOptions: EncodeOptions): void;
+};
+
+export default class OxiPNGEncoderOptions extends Component<Props, {}> {
+  @bind
+  onChange(event: Event) {
+    const form = (event.currentTarget as HTMLInputElement).closest('form') as HTMLFormElement;
+
+    const options: EncodeOptions = {
+      level: inputFieldValueAsNumber(form.level),
+    };
+    this.props.onChange(options);
+  }
+
+  render({ options }: Props) {
+    return (
+      <form class={style.optionsSection} onSubmit={preventDefault}>
+        <div class={style.optionOneCell}>
+          <Range
+            name="level"
+            min="0"
+            max="9"
+            step="1"
+            value={options.level}
+            onInput={this.onChange}
+          >
+            Effort:
+          </Range>
+        </div>
+      </form>
+    );
+  }
+}
diff --git a/src/codecs/processor-worker/index.ts b/src/codecs/processor-worker/index.ts
index d5367b46..8b80023b 100644
--- a/src/codecs/processor-worker/index.ts
+++ b/src/codecs/processor-worker/index.ts
@@ -41,6 +41,16 @@ async function optiPngEncode(
   return compress(data, options);
 }
 
+async function oxiPngEncode(
+  data: BufferSource, options: import('../oxipng/encoder-meta').EncodeOptions,
+): Promise<ArrayBuffer> {
+  const { compress } = await import(
+    /* webpackChunkName: "process-optipng" */
+    '../oxipng/encoder',
+  );
+  return compress(data, options);
+}
+
 async function webpEncode(
   data: ImageData, options: import('../webp/encoder-meta').EncodeOptions,
 ): Promise<ArrayBuffer> {
@@ -59,7 +69,15 @@ async function webpDecode(data: ArrayBuffer): Promise<ImageData> {
   return decode(data);
 }
 
-const exports = { mozjpegEncode, quantize, rotate, optiPngEncode, webpEncode, webpDecode };
+const exports = {
+  mozjpegEncode,
+  quantize,
+  rotate,
+  optiPngEncode,
+  oxiPngEncode,
+  webpEncode,
+  webpDecode,
+};
 export type ProcessorWorkerApi = typeof exports;
 
 expose(exports, self);
diff --git a/src/codecs/processor.ts b/src/codecs/processor.ts
index acaa69df..98aeebf1 100644
--- a/src/codecs/processor.ts
+++ b/src/codecs/processor.ts
@@ -3,6 +3,7 @@ import { QuantizeOptions } from './imagequant/processor-meta';
 import { canvasEncode, blobToArrayBuffer } from '../lib/util';
 import { EncodeOptions as MozJPEGEncoderOptions } from './mozjpeg/encoder-meta';
 import { EncodeOptions as OptiPNGEncoderOptions } from './optipng/encoder-meta';
+import { EncodeOptions as OxiPNGEncoderOptions } from './oxipng/encoder-meta';
 import { EncodeOptions as WebPEncoderOptions } from './webp/encoder-meta';
 import { EncodeOptions as BrowserJPEGOptions } from './browser-jpeg/encoder-meta';
 import { EncodeOptions as BrowserWebpEncodeOptions } from './browser-webp/encoder-meta';
@@ -147,6 +148,16 @@ export default class Processor {
     return this._workerApi!.optiPngEncode(pngBuffer, opts);
   }
 
+  @Processor._processingJob({ needsWorker: true })
+  async oxiPngEncode(
+    data: ImageData, opts: OxiPNGEncoderOptions,
+  ): Promise<ArrayBuffer> {
+    // OptiPNG expects PNG input.
+    const pngBlob = await canvasEncode(data, 'image/png');
+    const pngBuffer = await blobToArrayBuffer(pngBlob);
+    return this._workerApi!.oxiPngEncode(pngBuffer, opts);
+  }
+
   @Processor._processingJob({ needsWorker: true })
   webpEncode(data: ImageData, opts: WebPEncoderOptions): Promise<ArrayBuffer> {
     return this._workerApi!.webpEncode(data, opts);
diff --git a/src/components/compress/index.tsx b/src/components/compress/index.tsx
index 2bb90f03..24b94629 100644
--- a/src/components/compress/index.tsx
+++ b/src/components/compress/index.tsx
@@ -8,6 +8,7 @@ import Options from '../Options';
 import ResultCache from './result-cache';
 import * as identity from '../../codecs/identity/encoder-meta';
 import * as optiPNG from '../../codecs/optipng/encoder-meta';
+import * as oxiPNG from '../../codecs/oxipng/encoder-meta';
 import * as mozJPEG from '../../codecs/mozjpeg/encoder-meta';
 import * as webP from '../../codecs/webp/encoder-meta';
 import * as browserPNG from '../../codecs/browser-png/encoder-meta';
@@ -131,6 +132,7 @@ async function compressImage(
   const compressedData = await (() => {
     switch (encodeData.type) {
       case optiPNG.type: return processor.optiPngEncode(image, encodeData.options);
+      case oxiPNG.type: return processor.oxiPngEncode(image, encodeData.options);
       case mozJPEG.type: return processor.mozjpegEncode(image, encodeData.options);
       case webP.type: return processor.webpEncode(image, encodeData.options);
       case browserPNG.type: return processor.browserPngEncode(image);