diff --git a/.editorconfig b/.editorconfig
new file mode 100644
index 0000000..6e67130
--- /dev/null
+++ b/.editorconfig
@@ -0,0 +1,12 @@
+root = true
+
+[*]
+indent_style = space
+indent_size = 2
+end_of_line = lf
+charset = utf-8
+trim_trailing_whitespace = true
+insert_final_newline = true
+
+[*.php]
+indent_size = 4
diff --git a/.github/workflows/action.yml b/.github/workflows/action.yml
new file mode 100644
index 0000000..0a3c917
--- /dev/null
+++ b/.github/workflows/action.yml
@@ -0,0 +1,16 @@
+on: push
+name: Main Workflow
+jobs:
+  tests:
+    strategy:
+      matrix:
+        node: ['16', '14', '12']
+    name: Run NPM Stuff
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v1
+    - uses: actions/setup-node@v2
+      with:
+        node-version: ${{matrix.node}}
+    - run: npm install
+    - run: npm test
diff --git a/.npmignore b/.npmignore
index 32b3262..1dbbfcc 100644
--- a/.npmignore
+++ b/.npmignore
@@ -2,4 +2,6 @@
 .git
 node_modules/
 hashes/
-versions.txt
\ No newline at end of file
+versions.txt
+HACKING.md
+.editorconfig
diff --git a/README.md b/README.md
index c487ab7..7827495 100644
--- a/README.md
+++ b/README.md
@@ -34,89 +34,19 @@ You can sort or filter the returned versions if needed.
 All Stable electron releases for the following architectures are fingerprinted:
 
 - linux-x64
+- linux-arm64
 - darwin-x64 (Mac OS)
 - win32-x64 (Windows)
+- win32-arm64 (Windows)
+- darwin-arm64 (Apple Silicon)
 
 A list of release fingerprints is under the `hashes` directory.
 
-## todo
-
-- [ ] Add support for darwin-arm
-
 ## which files are present?
 
-Here's a count of file extensions present across all releases:
+Here's a count of the most common extensions present across all releases:
 
 ```
-      9 framework/Frameworks
-      9 Frameworks
-     13 app/Contents/MacOS/crash_report_sender
-     13 crash_report_sender
-     13 framework/Versions/A/Libraries/Libraries
-     13 framework/Versions/A/Resources/Inspector
-     13 Inspector
-     14 htaccess
-     15 npmignore
-     15 txt
-     26 1
-     26 strings
-     30 yml
-     45 markdown
-     50 framework/ReactiveObjC
-     50 framework/Versions/A/ReactiveObjC
-     59 4
-     70 11
-     72 app/Contents/MacOS/Electron Helper (GPU)
-     72 app/Contents/MacOS/Electron Helper (Plugin)
-     72 app/Contents/MacOS/Electron Helper (Renderer)
-     72 framework/Helpers
-     72 framework/Versions/A/Helpers/chrome_crashpad_handler
-     94 chrome_crashpad_handler
-     94 Helpers
-    100 ReactiveObjC
-    171 (GPU)
-    171 (Plugin)
-    171 (Renderer)
-    185 chrome-sandbox
-    223 app/Contents/MacOS/Electron Helper EH
-    223 app/Contents/MacOS/Electron Helper NP
-    223 EH
-    223 NP
-    230 framework/Versions/A/Resources/crashpad_handler
-    238 svg
-    262 framework/ReactiveCocoa
-    262 framework/Versions/A/ReactiveCocoa
-    312 app/Contents/MacOS/Electron
-    312 app/Contents/MacOS/Electron Helper
-    312 DS_Store
-    312 framework/Electron Framework
-    312 framework/Libraries
-    312 framework/Mantle
-    312 framework/Squirrel
-    312 framework/Versions/A/Electron Framework
-    312 framework/Versions/A/Mantle
-    312 framework/Versions/A/Resources/ShipIt
-    312 framework/Versions/A/Squirrel
-    357 crashpad_handler
-    436 electron
-    436 exe
-    436 ShipIt
-    449 Libraries
-    745 json
-    772 ReactiveCocoa
-    773 nib
-    774 icns
-    786 framework/Headers
-    786 framework/Modules
-    872 Framework
-    872 Mantle
-    872 Squirrel
-   1120 png
-   1158 Headers
-   1158 Modules
-   1248 framework/Resources
-   1248 framework/Versions/Current
-   1299 app/Contents/PkgInfo
    1620 dat
    1620 version
    1650 LICENSE
@@ -161,6 +91,11 @@ electron
 (Renderer)
 ```
 
+`which-electron` uses the following extensions and filenames to fingerprint:
+
+- `.h`, `.dll`, `.bin`, `.asar`, `.dylib`, `.so`, `.exe`
+- `electron framework`, `squirrel`, `electron`, `electron helper`, `chrome_100_percent`, `chrome_200_percent`
+
 ## license
 
 Released under WTFPL.
diff --git a/fingerprint.php b/fingerprint.php
index 8dbe500..7b199ef 100644
--- a/fingerprint.php
+++ b/fingerprint.php
@@ -11,57 +11,76 @@ function rsearch($dir) {
 }
 
 function generateFingerprint($version, $output, $hash_file) {
-	$manifest = [];
-	foreach(rsearch($output) as $file) {
-		$path = substr($file, strlen($output) + 1);
-		$manifest[$path] = sha1_file($file);
-	}
-	$json = json_encode($manifest, JSON_PRETTY_PRINT|JSON_UNESCAPED_SLASHES);
-	file_put_contents($hash_file, $json);
+    $manifest = [];
+    foreach(rsearch($output) as $file) {
+        $path = substr($file, strlen($output) + 1);
+        $manifest[$path] = sha1_file($file);
+    }
+    $json = json_encode($manifest, JSON_PRETTY_PRINT|JSON_UNESCAPED_SLASHES);
+    file_put_contents($hash_file, $json);
 }
 
 function download_release($url, $output) {
-	@unlink($output);
-	system("wget --quiet --max-redirect=5 '$url' -O /dev/shm/test.zip", $ret);
+    @unlink($output);
+    system("wget --quiet --max-redirect=5 '$url' -O /dev/shm/test.zip", $ret);
 
-	return ($ret === 0);
+    return ($ret === 0);
 }
 
 function extract_release($input, $output) {
-	$zip = new ZipArchive();
-	if (!$zip->open($input)) {
-		die("Download failed?");
-	}
-	`rm -rf $output`;
-	mkdir($output);
-	
-	if(!$zip->extractTo($output)) {
-		die("Failed extraction");
-	}
+    $zip = new ZipArchive();
+    if (!$zip->open($input)) {
+        die("Download failed?");
+    }
+    `rm -rf $output`;
+    mkdir($output);
 
-	$zip->close();
+    if(!$zip->extractTo($output)) {
+        die("Failed extraction");
+    }
+
+    $zip->close();
 }
 
-$archs = ['x64'];
+$archs = ['x64', 'arm64'];
 $oses = ['linux', 'darwin', 'win32'];
 
 foreach(file('versions.txt', FILE_IGNORE_NEW_LINES) as $version) {
-	foreach($oses as $os) {
-		foreach($archs as $arch) {
-			$hash_file = "hashes/$os-$arch-$version.json";
-			if (!file_exists($hash_file)) {
-				$zipfile = '/dev/shm/test.zip';
-				$output = '/dev/shm/electron';
-				$url = "https://github.com/electron/electron/releases/download/$version/electron-$version-$os-$arch.zip";
-				echo $url . PHP_EOL;
+    foreach($oses as $os) {
+        foreach($archs as $arch) {
 
-				if (download_release($url, $zipfile)) {
-					extract_release($zipfile, $output);
-					generateFingerprint($version, $output, $hash_file);	
-				} else {
-					echo "[DL:FAIL] $version\n";
-				}
-			}			
-		}
-	}
+            // No releases were made for these combinations
+            // Apple Silicon support added in v11: https://www.electronjs.org/blog/apple-silicon
+            if (version_compare($version, 'v11.0.0', '<') and $os=='darwin' and $arch=='arm64') {
+                continue;
+            }
+
+            // https://github.com/electron/electron/pull/10219
+            // v1.8.0 was the first arm64 release
+            if (version_compare($version, 'v1.8.0', '<') and $os=='linux' and $arch=='arm64') {
+                continue;
+            }
+
+            // 6.0.9 was the first ARM64 windows release (backport)
+            // https://github.com/electron/electron/pull/20260
+            if (version_compare($version, 'v6.0.9', '<') and $os=='win32' and $arch=='arm64') {
+                continue;
+            }
+
+            $hash_file = "hashes/$os-$arch-$version.json";
+            if (!file_exists($hash_file)) {
+                $zipfile = '/dev/shm/test.zip';
+                $output = '/dev/shm/electron';
+                $url = "https://github.com/electron/electron/releases/download/$version/electron-$version-$os-$arch.zip";
+                echo $url . PHP_EOL;
+
+                if (download_release($url, $zipfile)) {
+                    extract_release($zipfile, $output);
+                    generateFingerprint($version, $output, $hash_file);
+                } else {
+                    echo "[DL:FAIL] $version\n";
+                }
+            }
+        }
+    }
 }
diff --git a/index.js b/index.js
new file mode 100644
index 0000000..c993ab2
--- /dev/null
+++ b/index.js
@@ -0,0 +1,8 @@
+module.exports = {
+  "linux-x64": require('./linux-x64'),
+  "linux-arm64": require('./linux-arm64'),
+  "darwin-x64": require('./darwin-x64'),
+  "darwin-arm64": require('./darwin-arm64'),
+  "win32-x64": require('./win32-x64'),
+  "win32-arm64": require('./win32-arm64'),
+}
diff --git a/lookup-table.php b/lookup-table.php
index a4b7be3..f510a4f 100644
--- a/lookup-table.php
+++ b/lookup-table.php
@@ -1,27 +1,32 @@
 <?php
 
 $lookup = [
-	'win32-x64' => [],
-	'linux-x64' => [],
-	'darwin-x64' => []
+    'darwin-x64' => [],
+    'darwin-arm64' => [],
+    'linux-x64' => [],
+    'linux-arm64' => [],
+    'win32-x64' => [],
+    'win32-arm64' => [],
 ];
 
 foreach(glob('hashes/*.json') as $h) {
-	$data = json_decode(file_get_contents($h));
-	$name = basename($h, '.json');
-	list($os, $arch, $version) = explode('-', $name, 3);
-	foreach($data as $file=>$hash) {
-		// Including locales increases the file size by too much.
-		if (strpos($file, '.pak') !== false) {
-			continue;
-		}
-		$subTable = "$os-$arch";
-		if(!isset($lookup[$subTable][$hash])) {
-			$lookup[$subTable][$hash] = [];
-		}
-		$lookup[$subTable][$hash][] = $version;
-	}
+    $data = json_decode(file_get_contents($h));
+    $name = basename($h, '.json');
+    list($os, $arch, $version) = explode('-', $name, 3);
+    foreach($data as $file=>$hash) {
+        // Including locales increases the file size by too much.
+        if (strpos($file, '.pak') !== false and strlen(basename($file, '.pak') < 3)) {
+            continue;
+        }
+        $subTable = "$os-$arch";
+        if(!isset($lookup[$subTable][$hash])) {
+            $lookup[$subTable][$hash] = [];
+        }
+        $lookup[$subTable][$hash][] = $version;
+    }
 }
 
-$json = json_encode($lookup);
-file_put_contents('lookup.json', $json);
\ No newline at end of file
+foreach($lookup as $file => $data) {
+    $json = json_encode($data);
+    file_put_contents("$file.json", $json);
+}
diff --git a/test.js b/test.js
new file mode 100644
index 0000000..5e39ced
--- /dev/null
+++ b/test.js
@@ -0,0 +1,143 @@
+const L = require(".");
+const assert = require("assert");
+
+// ffmpeg.dll
+assert.deepEqual(L["win32-x64"]["baf786083f482c1f035e50e105b5f7475af1e00b"], [
+  "v1.4.3",
+  "v1.4.4",
+  "v1.4.5",
+]);
+
+// libEGL.dylib
+assert.deepEqual(L["darwin-x64"]["b904574843c22f7b39e986253b0c798548d2f01d"], [
+  "v12.0.10",
+  "v12.0.11",
+  "v12.0.12",
+  "v12.0.13",
+  "v12.0.14",
+  "v12.0.15",
+  "v12.0.2",
+  "v12.0.3",
+  "v12.0.4",
+  "v12.0.5",
+  "v12.0.6",
+  "v12.0.7",
+  "v12.0.8",
+  "v12.0.9",
+]);
+
+// chrome_100_percent.pak
+assert.deepEqual(L["linux-arm64"]["942e5f5414a24a1aa1769b9f8614ff8fbf40dba3"], [
+  "v12.0.0",
+  "v12.0.1",
+  "v12.0.10",
+  "v12.0.11",
+  "v12.0.12",
+  "v12.0.13",
+  "v12.0.14",
+  "v12.0.15",
+  "v12.0.2",
+  "v12.0.3",
+  "v12.0.4",
+  "v12.0.5",
+  "v12.0.6",
+  "v12.0.7",
+  "v12.0.8",
+  "v12.0.9",
+]);
+
+// snapshot_blob.bin
+assert.deepEqual(L["linux-x64"]["3fc441bcbacac544ba4af18dcd2b084694ae9409"], [
+  "v12.0.10",
+  "v12.0.11",
+  "v12.0.12",
+  "v12.0.13",
+  "v12.0.14",
+  "v12.0.15",
+  "v12.0.5",
+  "v12.0.6",
+  "v12.0.7",
+  "v12.0.8",
+  "v12.0.9",
+]);
+
+// libGLESv2.dll
+assert.deepEqual(L["win32-arm64"]["21f751ea45147f9e0b7107b8129ae4dd2fd1ccd6"], [
+  "v12.0.15",
+]);
+
+// d3dcompiler_47.dll
+assert.deepEqual(L["win32-x64"]["2256644f69435ff2fee76deb04d918083960d1eb"], [
+  "v10.0.0",
+  "v10.0.1",
+  "v10.1.0",
+  "v10.1.1",
+  "v10.1.2",
+  "v10.1.3",
+  "v10.1.4",
+  "v10.1.5",
+  "v10.1.6",
+  "v10.1.7",
+  "v10.2.0",
+  "v10.3.0",
+  "v10.3.1",
+  "v10.3.2",
+  "v10.4.0",
+  "v10.4.1",
+  "v10.4.2",
+  "v10.4.3",
+  "v10.4.4",
+  "v10.4.5",
+  "v10.4.6",
+  "v10.4.7",
+  "v11.0.0",
+  "v11.0.1",
+  "v11.0.2",
+  "v11.0.3",
+  "v11.0.4",
+  "v11.0.5",
+  "v11.1.0",
+  "v11.1.1",
+  "v11.2.0",
+  "v11.2.1",
+  "v11.2.2",
+  "v11.2.3",
+  "v11.3.0",
+  "v11.4.0",
+  "v11.4.1",
+  "v11.4.10",
+  "v11.4.2",
+  "v11.4.3",
+  "v11.4.4",
+  "v11.4.5",
+  "v11.4.6",
+  "v11.4.7",
+  "v11.4.8",
+  "v11.4.9",
+  "v12.0.0",
+  "v12.0.1",
+  "v12.0.10",
+  "v12.0.11",
+  "v12.0.12",
+  "v12.0.13",
+  "v12.0.14",
+  "v12.0.15",
+  "v12.0.2",
+  "v12.0.3",
+  "v12.0.4",
+  "v12.0.5",
+  "v12.0.6",
+  "v12.0.7",
+  "v12.0.8",
+  "v12.0.9",
+  "v13.0.0",
+  "v13.0.1",
+  "v13.1.0",
+  "v13.1.1",
+  "v13.1.2",
+  "v13.1.3",
+  "v13.1.4",
+  "v13.1.5",
+  "v13.1.6",
+  "v13.1.7",
+]);