diff --git a/tools/update-authors.js b/tools/update-authors.js
new file mode 100755
index 00000000000000..1c48eaec85c823
--- /dev/null
+++ b/tools/update-authors.js
@@ -0,0 +1,50 @@
+#!/usr/bin/env node
+// Usage: tools/update-author.js [--dry]
+// Passing --dry will redirect output to stdout rather than write to 'AUTHORS'.
+'use strict';
+const { spawn } = require('child_process');
+const fs = require('fs');
+const readline = require('readline');
+
+const log = spawn(
+  'git',
+  // Inspect author name/email and body.
+  ['log', '--reverse', '--format=Author: %aN <%aE>\n%b'], {
+    stdio: ['inherit', 'pipe', 'inherit']
+  });
+const rl = readline.createInterface({ input: log.stdout });
+
+let output;
+if (process.argv.includes('--dry'))
+  output = process.stdout;
+else
+  output = fs.createWriteStream('AUTHORS');
+
+output.write('# Authors ordered by first contribution.\n\n');
+
+const seen = new Set();
+
+// Support regular git author metadata, as well as `Author:` and
+// `Co-authored-by:` in the message body. Both have been used in the past
+// to indicate multiple authors per commit, with the latter standardized
+// by GitHub now.
+const authorRe =
+  /(^Author:|^Co-authored-by:)\s+(?<author>[^<]+)\s+(?<email><[^>]+>)/i;
+rl.on('line', (line) => {
+  const match = line.match(authorRe);
+  if (!match) return;
+
+  const { author, email } = match.groups;
+  if (seen.has(email) ||
+      /@chromium\.org/.test(email) ||
+      email === '<erik.corry@gmail.com>') {
+    return;
+  }
+
+  seen.add(email);
+  output.write(`${author} ${email}\n`);
+});
+
+rl.on('close', () => {
+  output.end('\n# Generated by tools/update-authors.js\n');
+});
diff --git a/tools/update-authors.sh b/tools/update-authors.sh
deleted file mode 100755
index d07d9c9ff73c43..00000000000000
--- a/tools/update-authors.sh
+++ /dev/null
@@ -1,22 +0,0 @@
-#!/bin/sh
-
-git log --reverse --format='%aN <%aE>' | perl -we '
-
-BEGIN {
-  %seen = (), @authors = ();
-}
-
-while (<>) {
-  next if $seen{$_};
-  next if /\@chromium.org/;
-  next if /<erik.corry\@gmail.com>/;
-  $seen{$_} = push @authors, $_;
-}
-
-END {
-  print "# Authors ordered by first contribution.\n";
-  print "\n", @authors, "\n";
-  print "# Generated by tools/update-authors.sh\n";
-}
-
-' > AUTHORS