diff --git a/codecs/oxipng/Cargo.lock b/codecs/oxipng/Cargo.lock
index 1fffe484..3192af13 100644
--- a/codecs/oxipng/Cargo.lock
+++ b/codecs/oxipng/Cargo.lock
@@ -1,10 +1,16 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
 [[package]]
-name = "adler32"
-version = "1.1.0"
+name = "adler"
+version = "0.2.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "567b077b825e468cc974f0020d4082ee6e03132512f207ef1a02fd5d00d1f32d"
+checksum = "ee2a4ec343196209d6594e19543ae87a39f96d5534d7174822a3ad825dd6ed7e"
+
+[[package]]
+name = "adler32"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5d2e7343e7fc9de883d1b0341e0b13970f764c14101234857d2ddafa1cb1cac2"
 
 [[package]]
 name = "autocfg"
@@ -32,9 +38,9 @@ checksum = "39092a32794787acd8525ee150305ff051b0aa6cc2abaf193924f5ab05425f39"
 
 [[package]]
 name = "bumpalo"
-version = "3.4.0"
+version = "3.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2e8c087f005730276d1096a652e92a8bacee2e2472bcc9715a74d2bec38b5820"
+checksum = "12ae9db68ad7fac5fe51304d20f016c911539251075a214f8e663babefa35187"
 
 [[package]]
 name = "bytemuck"
@@ -50,9 +56,9 @@ checksum = "08c48aae112d48ed9f069b33538ea9e3e90aa263cfa3d1c24309612b1f7472de"
 
 [[package]]
 name = "cc"
-version = "1.0.58"
+version = "1.0.50"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f9a06fb2e53271d7c279ec1efea6ab691c35a2ae67ec0d91d7acec0caf13b518"
+checksum = "95e28fa049fda1c330bcf9d723be7663a899c4679724b34c81e9f5a326aab8cd"
 
 [[package]]
 name = "cfg-if"
@@ -78,16 +84,6 @@ dependencies = [
  "cc",
 ]
 
-[[package]]
-name = "console_log"
-version = "0.2.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "501a375961cef1a0d44767200e66e4a559283097e91d0730b1d75dfb2f8a1494"
-dependencies = [
- "log",
- "web-sys",
-]
-
 [[package]]
 name = "crc"
 version = "1.8.1"
@@ -106,6 +102,16 @@ dependencies = [
  "cfg-if",
 ]
 
+[[package]]
+name = "crossbeam-channel"
+version = "0.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cced8691919c02aac3cb0a1bc2e9b73d89e832bf9a06fc579d4e71b68a2da061"
+dependencies = [
+ "crossbeam-utils",
+ "maybe-uninit",
+]
+
 [[package]]
 name = "crossbeam-deque"
 version = "0.7.3"
@@ -132,17 +138,6 @@ dependencies = [
  "scopeguard",
 ]
 
-[[package]]
-name = "crossbeam-queue"
-version = "0.2.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "774ba60a54c213d409d5353bda12d49cd68d14e45036a285234c8d6f91f92570"
-dependencies = [
- "cfg-if",
- "crossbeam-utils",
- "maybe-uninit",
-]
-
 [[package]]
 name = "crossbeam-utils"
 version = "0.7.2"
@@ -156,9 +151,9 @@ dependencies = [
 
 [[package]]
 name = "deflate"
-version = "0.8.6"
+version = "0.8.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "73770f8e1fe7d64df17ca66ad28994a0a623ea497fa69486e14984e715c5d174"
+checksum = "050ef6de42a33903b30a7497b76b40d3d58691d4d3eec355348c122444a388f0"
 dependencies = [
  "adler32",
  "byteorder",
@@ -171,19 +166,25 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "bb1f6b1ce1c140482ea30ddd3335fc0024ac7ee112895426e0a629a6c20adfe3"
 
 [[package]]
-name = "hermit-abi"
-version = "0.1.15"
+name = "hashbrown"
+version = "0.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3deed196b6e7f9e44a2ae8d94225d80302d81208b1bb673fd21fe634645c85a9"
+checksum = "00d63df3d41950fb462ed38308eea019113ad1508da725bbedcd0fa5a85ef5f7"
+
+[[package]]
+name = "hermit-abi"
+version = "0.1.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "725cf19794cf90aa94e65050cb4191ff5d8fa87a498383774c47b332e3af952e"
 dependencies = [
  "libc",
 ]
 
 [[package]]
 name = "image"
-version = "0.23.7"
+version = "0.23.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a2397fc43bd5648b7117aabb3c5e62d0e62c194826ec77b0b4d0c41e62744635"
+checksum = "9062b90712d25bc6bb165d110aa59c6b47c849246e341e7b86a98daff9d49f60"
 dependencies = [
  "bytemuck",
  "byteorder",
@@ -195,14 +196,24 @@ dependencies = [
 
 [[package]]
 name = "indexmap"
-version = "1.4.0"
+version = "1.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c398b2b113b55809ceb9ee3e753fcbac793f1956663f3c36549c1346015c2afe"
+checksum = "55e2e4c765aa53a0424761bf9f41aa7a6ac1efa87238f59560640e27fca028f2"
 dependencies = [
  "autocfg",
+ "hashbrown",
  "rayon",
 ]
 
+[[package]]
+name = "inflate"
+version = "0.4.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1cdb29978cc5797bd8dcc8e5bf7de604891df2a8dc576973d71a281e916db2ff"
+dependencies = [
+ "adler32",
+]
+
 [[package]]
 name = "itertools"
 version = "0.9.0"
@@ -212,15 +223,6 @@ dependencies = [
  "either",
 ]
 
-[[package]]
-name = "js-sys"
-version = "0.3.41"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c4b9172132a62451e56142bff9afc91c8e4a4500aa5b847da36815b63bfda916"
-dependencies = [
- "wasm-bindgen",
-]
-
 [[package]]
 name = "lazy_static"
 version = "1.4.0"
@@ -229,24 +231,33 @@ checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
 
 [[package]]
 name = "libc"
-version = "0.2.72"
+version = "0.2.68"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a9f8082297d534141b30c8d39e9b1773713ab50fdbe4ff30f750d063b3bfd701"
+checksum = "dea0c0405123bba743ee3f91f49b1c7cfb684eef0da0a50110f758ccf24cdff0"
 
 [[package]]
-name = "libdeflater"
-version = "0.2.0"
+name = "libdeflate-sys"
+version = "0.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "66dca08b13369865b2f6dca1dd05f833985cbe6c12a676b04d55f78b85e80246"
+checksum = "21e39efa87b84db3e13ff4e2dfac1e57220abcbd7fe8ec44d238f7f4f787cc1f"
 dependencies = [
  "cc",
 ]
 
 [[package]]
-name = "log"
-version = "0.4.8"
+name = "libdeflater"
+version = "0.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "14b6052be84e6b71ab17edffc2eeabf5c2c3ae1fdb464aae35ac50c67a44e1f7"
+checksum = "a4810980d791f26d470e2d7d91a3d4d22aa3a4b709fb7e9c5e43ee54f83a01f2"
+dependencies = [
+ "libdeflate-sys",
+]
+
+[[package]]
+name = "log"
+version = "0.4.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4fabed175da42fed1fa0746b0ea71f412aa9d35e76e95e59b192c64b9dc2bf8b"
 dependencies = [
  "cfg-if",
 ]
@@ -259,27 +270,28 @@ checksum = "60302e4db3a61da70c0cb7991976248362f30319e88850c487b9b95bbf059e00"
 
 [[package]]
 name = "memoffset"
-version = "0.5.5"
+version = "0.5.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c198b026e1bbf08a937e94c6c60f9ec4a2267f5b0d2eec9c1b21b061ce2be55f"
+checksum = "b4fc2c02a7e374099d4ee95a193111f72d2110197fe200272371758f6c3643d8"
 dependencies = [
  "autocfg",
 ]
 
 [[package]]
 name = "miniz_oxide"
-version = "0.3.7"
+version = "0.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "791daaae1ed6889560f8c4359194f56648355540573244a5448a83ba1ecc7435"
+checksum = "c60c0dfe32c10b43a144bad8fc83538c52f58302c92300ea7ec7bf7b38d5a7b9"
 dependencies = [
- "adler32",
+ "adler",
+ "autocfg",
 ]
 
 [[package]]
 name = "num-integer"
-version = "0.1.43"
+version = "0.1.42"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8d59457e662d541ba17869cf51cf177c0b5f0cbf476c66bdc90bf1edac4f875b"
+checksum = "3f6ea62e9d81a77cd3ee9a2a5b9b609447857f3d358704331e4ef39eb247fcba"
 dependencies = [
  "autocfg",
  "num-traits",
@@ -287,9 +299,9 @@ dependencies = [
 
 [[package]]
 name = "num-iter"
-version = "0.1.41"
+version = "0.1.40"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7a6e6b7c748f995c4c29c5f5ae0248536e04a5739927c74ec0fa564805094b9f"
+checksum = "dfb0800a0291891dd9f4fe7bd9c19384f98f7fbe0cd0f39a2c6b88b9868bbc00"
 dependencies = [
  "autocfg",
  "num-integer",
@@ -298,9 +310,9 @@ dependencies = [
 
 [[package]]
 name = "num-rational"
-version = "0.3.0"
+version = "0.2.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a5b4d7360f362cfb50dde8143501e6940b22f644be75a4cc90b2d81968908138"
+checksum = "5c000134b5dbf44adc5cb772486d335293351644b801551abe8f75c84cfa4aef"
 dependencies = [
  "autocfg",
  "num-integer",
@@ -309,28 +321,34 @@ dependencies = [
 
 [[package]]
 name = "num-traits"
-version = "0.2.12"
+version = "0.2.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ac267bcc07f48ee5f8935ab0d24f316fb722d7a1292e2913f0cc196b29ffd611"
+checksum = "c62be47e61d1842b9170f0fdeec8eba98e60e90e5446449a0545e5152acd7096"
 dependencies = [
  "autocfg",
 ]
 
 [[package]]
 name = "num_cpus"
-version = "1.13.0"
+version = "1.12.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "05499f3756671c15885fee9034446956fff3f243d6077b91e5767df161f766b3"
+checksum = "46203554f085ff89c235cd12f7075f3233af9b11ed7c9e16dfe2560d03313ce6"
 dependencies = [
  "hermit-abi",
  "libc",
 ]
 
 [[package]]
-name = "oxipng"
-version = "3.0.0"
+name = "once_cell"
+version = "1.3.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d5fd695858078338d73862ff3755f820eff0bf4f3304e4b52f22aba53463183a"
+checksum = "b1c601810575c99596d4afc46f78a678c80105117c379eb3650cf99b8a21ce5b"
+
+[[package]]
+name = "oxipng"
+version = "3.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5687a277f33b5fe5ee2ff5ceab4417885a428a1a938e944aa7df9d7e58c35762"
 dependencies = [
  "bit-vec",
  "byteorder",
@@ -344,44 +362,45 @@ dependencies = [
  "miniz_oxide",
  "rayon",
  "rgb",
+ "rustc_version",
  "zopfli",
 ]
 
 [[package]]
 name = "png"
-version = "0.16.6"
+version = "0.16.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c150bf7479fafe3dd8740dbe48cc33b2a3efb7b0fe3483aced8bbc39f6d0238d"
+checksum = "46060468187c21c00ffa2a920690b29997d7fd543f5a4d400461e4a7d4fccde8"
 dependencies = [
  "bitflags",
  "crc32fast",
  "deflate",
- "miniz_oxide",
+ "inflate",
 ]
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.18"
+version = "1.0.21"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "beae6331a816b1f65d04c45b078fd8e6c93e8071771f41b8163255bbd8d7c8fa"
+checksum = "36e28516df94f3dd551a587da5357459d9b36d945a7c37c3557928c1c2ff2a2c"
 dependencies = [
  "unicode-xid",
 ]
 
 [[package]]
 name = "quote"
-version = "1.0.7"
+version = "1.0.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "aa563d17ecb180e500da1cfd2b028310ac758de548efdd203e18f283af693f37"
+checksum = "2bdc6c187c65bca4260c9011c9e3132efe4909da44726bad24cf7572ae338d7f"
 dependencies = [
  "proc-macro2",
 ]
 
 [[package]]
 name = "rayon"
-version = "1.3.1"
+version = "1.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "62f02856753d04e03e26929f820d0a0a337ebe71f849801eea335d464b349080"
+checksum = "cfd016f0c045ad38b5251be2c9c0ab806917f82da4d36b2a327e5166adad9270"
 dependencies = [
  "autocfg",
  "crossbeam-deque",
@@ -391,12 +410,12 @@ dependencies = [
 
 [[package]]
 name = "rayon-core"
-version = "1.7.1"
+version = "1.8.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e92e15d89083484e11353891f1af602cc661426deb9564c298b270c726973280"
+checksum = "e8c4fec834fb6e6d2dd5eece3c7b432a52f0ba887cf40e595190c4107edc08bf"
 dependencies = [
+ "crossbeam-channel",
  "crossbeam-deque",
- "crossbeam-queue",
  "crossbeam-utils",
  "lazy_static",
  "num_cpus",
@@ -404,26 +423,50 @@ dependencies = [
 
 [[package]]
 name = "rgb"
-version = "0.8.20"
+version = "0.8.25"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "90ef54b45ae131327a88597e2463fee4098ad6c88ba7b6af4b3987db8aad4098"
+checksum = "287f3c3f8236abb92d8b7e36797f19159df4b58f0a658cc3fb6dd3004b1f3bd3"
 dependencies = [
  "bytemuck",
 ]
 
+[[package]]
+name = "rustc_version"
+version = "0.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "138e3e0acb6c9fb258b19b67cb8abd63c00679d2851805ea151465464fe9030a"
+dependencies = [
+ "semver",
+]
+
 [[package]]
 name = "scopeguard"
 version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d29ab0c6d3fc0ee92fe66e2d99f700eab17a8d57d1c1d3b748380fb20baa78cd"
 
+[[package]]
+name = "semver"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1d7eb9ef2c18661902cc47e535f9bc51b78acd254da71d375c2f6720d9a40403"
+dependencies = [
+ "semver-parser",
+]
+
+[[package]]
+name = "semver-parser"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "388a1df253eca08550bef6c72392cfe7c30914bf41df5269b68cbd6ff8f570a3"
+
 [[package]]
 name = "squoosh-oxipng"
 version = "0.1.0"
 dependencies = [
- "console_log",
- "js-sys",
+ "crossbeam-deque",
  "log",
+ "once_cell",
  "oxipng",
  "rayon",
  "wasm-bindgen",
@@ -431,9 +474,9 @@ dependencies = [
 
 [[package]]
 name = "syn"
-version = "1.0.34"
+version = "1.0.41"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "936cae2873c940d92e697597c5eee105fb570cd5689c695806f672883653349b"
+checksum = "6690e3e9f692504b941dc6c3b188fd28df054f7fb8469ab40680df52fdcc842b"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -448,15 +491,15 @@ checksum = "a9b2228007eba4120145f785df0f6c92ea538f5a3635a612ecf4e334c8c1446d"
 
 [[package]]
 name = "unicode-xid"
-version = "0.2.1"
+version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f7fe0bb3479651439c9112f72b6c505038574c9fbb575ed1bf3b797fa39dd564"
+checksum = "826e7639553986605ec5979c7dd957c7895e93eabed50ab2ffa7f6128a75097c"
 
 [[package]]
 name = "wasm-bindgen"
-version = "0.2.64"
+version = "0.2.68"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6a634620115e4a229108b71bde263bb4220c483b3f07f5ba514ee8d15064c4c2"
+checksum = "1ac64ead5ea5f05873d7c12b545865ca2b8d28adfc50a49b84770a3a97265d42"
 dependencies = [
  "cfg-if",
  "wasm-bindgen-macro",
@@ -464,9 +507,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-backend"
-version = "0.2.64"
+version = "0.2.68"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3e53963b583d18a5aa3aaae4b4c1cb535218246131ba22a71f05b518098571df"
+checksum = "f22b422e2a757c35a73774860af8e112bff612ce6cb604224e8e47641a9e4f68"
 dependencies = [
  "bumpalo",
  "lazy_static",
@@ -479,9 +522,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-macro"
-version = "0.2.64"
+version = "0.2.68"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3fcfd5ef6eec85623b4c6e844293d4516470d8f19cd72d0d12246017eb9060b8"
+checksum = "6b13312a745c08c469f0b292dd2fcd6411dba5f7160f593da6ef69b64e407038"
 dependencies = [
  "quote",
  "wasm-bindgen-macro-support",
@@ -489,9 +532,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-macro-support"
-version = "0.2.64"
+version = "0.2.68"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9adff9ee0e94b926ca81b57f57f86d5545cdcb1d259e21ec9bdd95b901754c75"
+checksum = "f249f06ef7ee334cc3b8ff031bfc11ec99d00f34d86da7498396dc1e3b1498fe"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -502,19 +545,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-shared"
-version = "0.2.64"
+version = "0.2.68"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7f7b90ea6c632dd06fd765d44542e234d5e63d9bb917ecd64d79778a13bd79ae"
-
-[[package]]
-name = "web-sys"
-version = "0.3.41"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "863539788676619aac1a23e2df3655e96b32b0e05eb72ca34ba045ad573c625d"
-dependencies = [
- "js-sys",
- "wasm-bindgen",
-]
+checksum = "1d649a3145108d7d3fbcde896a468d1bd636791823c9921135218ad89be08307"
 
 [[package]]
 name = "zopfli"
diff --git a/codecs/oxipng/Cargo.toml b/codecs/oxipng/Cargo.toml
index bc9e1947..a5c1273e 100644
--- a/codecs/oxipng/Cargo.toml
+++ b/codecs/oxipng/Cargo.toml
@@ -13,9 +13,12 @@ oxipng = { version = "3.0.0", default-features = false, features = ["parallel"]
 wasm-bindgen = "0.2.64"
 log = { version = "0.4", features = ["release_max_level_off"] }
 rayon = "1.3.0"
-js-sys = "0.3.37"
-console_log = "0.2.0"
+crossbeam-deque = "0.7.3"
+once_cell = "1.3.1"
 
 [profile.release]
 lto = true
 opt-level = "s"
+
+[package.metadata.wasm-pack.profile.release]
+wasm-opt = ["-O", "--no-validation"]
diff --git a/codecs/oxipng/build.sh b/codecs/oxipng/build.sh
index 20a5994b..ebe32368 100644
--- a/codecs/oxipng/build.sh
+++ b/codecs/oxipng/build.sh
@@ -6,6 +6,7 @@ echo "============================================="
 echo "Compiling wasm"
 echo "============================================="
 (
+  rm -rf pkg
   CC=/opt/wasi-sdk/bin/clang RUSTFLAGS='-C target-feature=+atomics,+bulk-memory' rustup run nightly wasm-pack build -t web -- -Z build-std=panic_abort,std
   rm pkg/.gitignore
 )
diff --git a/codecs/oxipng/main.js b/codecs/oxipng/main.js
deleted file mode 100644
index 629127bb..00000000
--- a/codecs/oxipng/main.js
+++ /dev/null
@@ -1,27 +0,0 @@
-import initOxiPNG, { start_main_thread, optimise } from './pkg/squoosh_oxipng.js';
-import wasmUrl from "./pkg/squoosh_oxipng_bg.wasm";
-
-async function startMainThread() {
-  await initOxiPNG(fetch(wasmUrl));
-  start_main_thread({
-    length: navigator.hardwareConcurrency,
-    pop: () => ({
-      postMessage: data => {
-        postMessage({ type: 'spawn', data });
-      }
-    })
-  });
-  return {
-    optimise
-  };
-}
-
-const mainThread = startMainThread();
-addEventListener('message', async ({ data: { id, args } }) => {
-  try {
-    let result = (await mainThread).optimise(...args);
-    postMessage({ ok: true, id, result });
-  } catch (result) {
-    postMessage({ ok: false, id, result });
-  }
-});
diff --git a/codecs/oxipng/pkg/squoosh_oxipng.d.ts b/codecs/oxipng/pkg/squoosh_oxipng.d.ts
index 49f6a286..58683e41 100644
--- a/codecs/oxipng/pkg/squoosh_oxipng.d.ts
+++ b/codecs/oxipng/pkg/squoosh_oxipng.d.ts
@@ -1,13 +1,16 @@
 /* tslint:disable */
 /* eslint-disable */
 /**
-* @param {Array<any>} workers
+* @returns {any}
 */
-export function start_main_thread(workers: Array<any>): void;
+export function worker_initializer(): any;
 /**
-* @param {number} thread
+* @param {number} num
 */
-export function start_worker_thread(thread: number): void;
+export function start_main_thread(num: number): void;
+/**
+*/
+export function start_worker_thread(): void;
 /**
 * @param {Uint8Array} data
 * @param {number} level
@@ -18,8 +21,9 @@ export function optimise(data: Uint8Array, level: number): Uint8Array;
 export type InitInput = RequestInfo | URL | Response | BufferSource | WebAssembly.Module;
 
 export interface InitOutput {
+  readonly worker_initializer: () => number;
   readonly start_main_thread: (a: number) => void;
-  readonly start_worker_thread: (a: number) => void;
+  readonly start_worker_thread: () => void;
   readonly optimise: (a: number, b: number, c: number, d: number) => void;
   readonly malloc: (a: number) => number;
   readonly free: (a: number) => void;
diff --git a/codecs/oxipng/pkg/squoosh_oxipng.js b/codecs/oxipng/pkg/squoosh_oxipng.js
index adf082cf..53d14fc9 100644
--- a/codecs/oxipng/pkg/squoosh_oxipng.js
+++ b/codecs/oxipng/pkg/squoosh_oxipng.js
@@ -6,22 +6,8 @@ const heap = new Array(32).fill(undefined);
 
 heap.push(undefined, null, true, false);
 
-function getObject(idx) { return heap[idx]; }
-
 let heap_next = heap.length;
 
-function dropObject(idx) {
-    if (idx < 36) return;
-    heap[idx] = heap_next;
-    heap_next = idx;
-}
-
-function takeObject(idx) {
-    const ret = getObject(idx);
-    dropObject(idx);
-    return ret;
-}
-
 function addHeapObject(obj) {
     if (heap_next === heap.length) heap.push(heap.length + 1);
     const idx = heap_next;
@@ -46,18 +32,39 @@ function getUint8Memory0() {
 function getStringFromWasm0(ptr, len) {
     return cachedTextDecoder.decode(getUint8Memory0().slice(ptr, ptr + len));
 }
+
+function getObject(idx) { return heap[idx]; }
+
+function dropObject(idx) {
+    if (idx < 36) return;
+    heap[idx] = heap_next;
+    heap_next = idx;
+}
+
+function takeObject(idx) {
+    const ret = getObject(idx);
+    dropObject(idx);
+    return ret;
+}
 /**
-* @param {Array<any>} workers
+* @returns {any}
 */
-export function start_main_thread(workers) {
-    wasm.start_main_thread(addHeapObject(workers));
+export function worker_initializer() {
+    var ret = wasm.worker_initializer();
+    return takeObject(ret);
 }
 
 /**
-* @param {number} thread
+* @param {number} num
 */
-export function start_worker_thread(thread) {
-    wasm.start_worker_thread(thread);
+export function start_main_thread(num) {
+    wasm.start_main_thread(num);
+}
+
+/**
+*/
+export function start_worker_thread() {
+    wasm.start_worker_thread();
 }
 
 let WASM_VECTOR_LEN = 0;
@@ -86,14 +93,20 @@ function getArrayU8FromWasm0(ptr, len) {
 * @returns {Uint8Array}
 */
 export function optimise(data, level) {
-    var ptr0 = passArray8ToWasm0(data, wasm.__wbindgen_malloc);
-    var len0 = WASM_VECTOR_LEN;
-    wasm.optimise(8, ptr0, len0, level);
-    var r0 = getInt32Memory0()[8 / 4 + 0];
-    var r1 = getInt32Memory0()[8 / 4 + 1];
-    var v1 = getArrayU8FromWasm0(r0, r1).slice();
-    wasm.__wbindgen_free(r0, r1 * 1);
-    return v1;
+    try {
+        const retptr = wasm.__wbindgen_export_1.value - 16;
+        wasm.__wbindgen_export_1.value = retptr;
+        var ptr0 = passArray8ToWasm0(data, wasm.__wbindgen_malloc);
+        var len0 = WASM_VECTOR_LEN;
+        wasm.optimise(retptr, ptr0, len0, level);
+        var r0 = getInt32Memory0()[retptr / 4 + 0];
+        var r1 = getInt32Memory0()[retptr / 4 + 1];
+        var v1 = getArrayU8FromWasm0(r0, r1).slice();
+        wasm.__wbindgen_free(r0, r1 * 1);
+        return v1;
+    } finally {
+        wasm.__wbindgen_export_1.value += 16;
+    }
 }
 
 async function load(module, imports, maybe_memory) {
@@ -135,40 +148,18 @@ async function init(input, maybe_memory) {
     }
     const imports = {};
     imports.wbg = {};
-    imports.wbg.__wbg_length_8dacd620a01b769a = function(arg0) {
-        var ret = getObject(arg0).length;
-        return ret;
-    };
-    imports.wbg.__wbindgen_object_drop_ref = function(arg0) {
-        takeObject(arg0);
-    };
-    imports.wbg.__wbg_pop_e063afe6cb737ed3 = function(arg0) {
-        var ret = getObject(arg0).pop();
-        return addHeapObject(ret);
-    };
-    imports.wbg.__wbg_new_891c121bc64f5c10 = function() {
-        var ret = new Array();
-        return addHeapObject(ret);
-    };
     imports.wbg.__wbindgen_module = function() {
         var ret = init.__wbindgen_wasm_module;
         return addHeapObject(ret);
     };
-    imports.wbg.__wbg_push_ffe5167b83871629 = function(arg0, arg1) {
-        var ret = getObject(arg0).push(getObject(arg1));
-        return ret;
-    };
     imports.wbg.__wbindgen_memory = function() {
         var ret = wasm.__wbindgen_export_0;
         return addHeapObject(ret);
     };
-    imports.wbg.__wbindgen_number_new = function(arg0) {
-        var ret = arg0;
+    imports.wbg.__wbg_of_6510501edc06d65e = function(arg0, arg1) {
+        var ret = Array.of(takeObject(arg0), takeObject(arg1));
         return addHeapObject(ret);
     };
-    imports.wbg.__wbg_postMessage_5ab140e61ca2cb42 = function(arg0, arg1) {
-        getObject(arg0).postMessage(takeObject(arg1));
-    };
     imports.wbg.__wbindgen_throw = function(arg0, arg1) {
         throw new Error(getStringFromWasm0(arg0, arg1));
     };
diff --git a/codecs/oxipng/pkg/squoosh_oxipng_bg.wasm b/codecs/oxipng/pkg/squoosh_oxipng_bg.wasm
index 47edeaca..98d53e78 100644
Binary files a/codecs/oxipng/pkg/squoosh_oxipng_bg.wasm and b/codecs/oxipng/pkg/squoosh_oxipng_bg.wasm differ
diff --git a/codecs/oxipng/pkg/squoosh_oxipng_bg.d.ts b/codecs/oxipng/pkg/squoosh_oxipng_bg.wasm.d.ts
similarity index 83%
rename from codecs/oxipng/pkg/squoosh_oxipng_bg.d.ts
rename to codecs/oxipng/pkg/squoosh_oxipng_bg.wasm.d.ts
index d4a083ca..832b7200 100644
--- a/codecs/oxipng/pkg/squoosh_oxipng_bg.d.ts
+++ b/codecs/oxipng/pkg/squoosh_oxipng_bg.wasm.d.ts
@@ -1,7 +1,8 @@
 /* tslint:disable */
 /* eslint-disable */
+export function worker_initializer(): number;
 export function start_main_thread(a: number): void;
-export function start_worker_thread(a: number): void;
+export function start_worker_thread(): void;
 export function optimise(a: number, b: number, c: number, d: number): void;
 export function malloc(a: number): number;
 export function free(a: number): void;
diff --git a/codecs/oxipng/spawn.js b/codecs/oxipng/spawn.js
index 624bb830..5bcaa96e 100644
--- a/codecs/oxipng/spawn.js
+++ b/codecs/oxipng/spawn.js
@@ -1,32 +1,23 @@
-let main = new Worker("./main.js", { type: "module" });
+import initOxiPNG, { worker_initializer, start_main_thread, optimise } from './pkg/oxipng.js';
+import wasmUrl from "./pkg/oxipng_bg.wasm";
 
-let workers = Array.from(
-  { length: navigator.hardwareConcurrency },
-  () => new Worker("./worker.js", { type: "module" })
-);
-
-main.addEventListener('message', ({ data: { type, data } }) => {
-  if (type === 'spawn') {
-    workers.pop().postMessage(data);
+async function startMainThread() {
+  let num = navigator.hardwareConcurrency;
+  await initOxiPNG(fetch(wasmUrl));
+  let workerInit = worker_initializer();
+  let workers = [];
+  for (let i = 0; i < num; i++) {
+    workers.push(new Promise(resolve => {
+      let worker = new Worker("./worker.js", { type: "module" });
+      worker.postMessage(workerInit);
+      worker.addEventListener('message', resolve, { once: true });
+    }));
   }
-});
-
-let ID = 0;
-
-export function optimise(...args) {
-  return new Promise((resolve, reject) => {
-    let sendId = ID++;
-
-    main.addEventListener('message', function onMessage({ data: { ok, id, result } }) {
-      if (id !== sendId) return;
-      main.removeEventListener('message', onMessage);
-      if (ok) {
-        resolve(result);
-      } else {
-        reject(result);
-      }
-    });
-
-    main.postMessage({ id: sendId, args });
-  });
+  await Promise.all(workers);
+  start_main_thread(num);
+  return {
+    optimise
+  };
 }
+
+export default startMainThread();
diff --git a/codecs/oxipng/src/lib.rs b/codecs/oxipng/src/lib.rs
index 9b8401ab..a494604e 100644
--- a/codecs/oxipng/src/lib.rs
+++ b/codecs/oxipng/src/lib.rs
@@ -1,42 +1,44 @@
 mod malloc_shim;
 
-use js_sys::Array;
+use crossbeam_deque::Injector;
+use once_cell::sync::OnceCell;
 use wasm_bindgen::prelude::*;
-use wasm_bindgen::{JsCast, JsValue};
+use wasm_bindgen::JsValue;
 use oxipng::AlphaOptim;
 
 #[wasm_bindgen]
 extern "C" {
-    type Worker;
+    #[wasm_bindgen(js_namespace = Array, js_name = of)]
+    fn array_of_2(a: JsValue, b: JsValue) -> JsValue;
+}
 
-    #[wasm_bindgen(method, js_name = postMessage)]
-    fn post_message(worker: &Worker, msg: JsValue);
+static TASKS: OnceCell<Injector<rayon::ThreadBuilder>> = OnceCell::new();
+
+#[wasm_bindgen]
+pub fn worker_initializer() -> JsValue {
+    TASKS.get_or_init(Injector::new);
+    array_of_2(wasm_bindgen::module(), wasm_bindgen::memory())
 }
 
 #[wasm_bindgen]
-pub fn start_main_thread(workers: Array) {
-    // console_log::init_with_level(log::Level::Trace);
+pub fn start_main_thread(num: usize) {
+    let tasks = TASKS.get().unwrap();
 
     rayon::ThreadPoolBuilder::new()
-        .num_threads(workers.length() as _)
-        .spawn_handler(move |thread| {
-            Ok(workers.pop().unchecked_into::<Worker>().post_message({
-                let arr = Array::new();
-                arr.push(&wasm_bindgen::module());
-                arr.push(&wasm_bindgen::memory());
-                arr.push(&JsValue::from(Box::into_raw(Box::new(thread)) as u32));
-                arr.into()
-            }))
-        })
+        .num_threads(num)
+        .spawn_handler(|thread| Ok(tasks.push(thread)))
         .build_global()
         .unwrap_throw()
 }
 
 #[wasm_bindgen]
-pub fn start_worker_thread(thread: *mut rayon::ThreadBuilder) {
-  // console_log::init_with_level(log::Level::Trace);
-
-  unsafe { Box::from_raw(thread) }.run()
+pub fn start_worker_thread() {
+    let tasks = TASKS.get().unwrap();
+    loop {
+        if let crossbeam_deque::Steal::Success(task) = tasks.steal() {
+            return task.run();
+        }
+    }
 }
 
 #[wasm_bindgen(catch)]
diff --git a/codecs/oxipng/worker.js b/codecs/oxipng/worker.js
index 00a99dc2..0778cdff 100644
--- a/codecs/oxipng/worker.js
+++ b/codecs/oxipng/worker.js
@@ -1,8 +1,7 @@
 import initOxiPNG, { start_worker_thread } from './pkg/squoosh_oxipng.js';
 
-addEventListener('message', async ({ data: [module, memory, threadPtr] }) => {
-  // console.log([module, memory, threadPtr]);
+addEventListener('message', async ({ data: [module, memory] }) => {
+  postMessage(null);
   await initOxiPNG(module, memory);
-  // console.log('Starting', threadPtr);
-  start_worker_thread(threadPtr);
+  start_worker_thread();
 }, { once: true });
diff --git a/src/codecs/oxipng/encoder.ts b/src/codecs/oxipng/encoder.ts
index 0c605a86..69b17091 100644
--- a/src/codecs/oxipng/encoder.ts
+++ b/src/codecs/oxipng/encoder.ts
@@ -1,7 +1,7 @@
 // @ts-ignore
-import { optimise } from '../../../codecs/oxipng/spawn.js';
+import optimiser from '../../../codecs/oxipng/spawn.js';
 import { EncodeOptions } from './encoder-meta';
 
 export async function compress(data: ArrayBuffer, options: EncodeOptions): Promise<ArrayBuffer> {
-  return (await optimise(new Uint8Array(data), options.level)).buffer;
+  return (await optimiser).optimise(new Uint8Array(data), options.level).buffer;
 }