diff --git a/.env.sample b/.env.sample
index 12ca5abc..6cb83b7c 100644
--- a/.env.sample
+++ b/.env.sample
@@ -8,6 +8,7 @@ DATA_DIR=/home/respec.org/data
 
 # GitHub webhook secrets
 W3C_WEBREF_SECRET=xxxxxxxxxxxxxxxxxxxxxx
+W3C_GROUPS_SECRET=xxxxxxxxxxxxxxxxxxxxxx
 CANIUSE_SECRET=xxxxxxxxxxxxxxxxxxxxxx
 RESPEC_SECRET=xxxxxxxxxxxxxxxxxxxxxx
 WEB_FEATURES_SECRET=xxxxxxxxxxxxxxxxxxxxxx
diff --git a/routes/w3c/group.ts b/routes/w3c/group.ts
index f3c0be05..984137ab 100644
--- a/routes/w3c/group.ts
+++ b/routes/w3c/group.ts
@@ -18,7 +18,7 @@ type GroupType = "wg" | "cg" | "ig" | "bg" | "other";
 export type Groups = Record<string, GroupMeta>;
 export type GroupsByType = Record<GroupType, Groups>;
 
-const groups: GroupsByType = JSON.parse(readFileSync(dataSource, "utf-8"));
+const EMPTY_GROUPS: GroupsByType = { wg: {}, cg: {}, ig: {}, bg: {}, other: {} };
 
 interface Group {
   id: number;
@@ -32,6 +32,24 @@ interface Group {
 }
 const cache = new MemCache<Group>(ms("1 day"));
 
+let groups: GroupsByType = EMPTY_GROUPS;
+try {
+  groups = JSON.parse(readFileSync(dataSource, "utf-8"));
+} catch (error) {
+  console.error("Failed to parse groups.json at startup:", error);
+}
+
+export function reloadGroups(): boolean {
+  try {
+    groups = JSON.parse(readFileSync(dataSource, "utf-8"));
+    cache.clear();
+    return true;
+  } catch (error) {
+    console.error("Failed to reload groups.json:", error);
+    return false;
+  }
+}
+
 // Support non W3C shortnames for backward compatibility.
 const LEGACY_SHORTNAMES = new Map([
   ["wai-apa", "apa"],
diff --git a/routes/w3c/index.ts b/routes/w3c/index.ts
index 4a809574..3bdcc40f 100644
--- a/routes/w3c/index.ts
+++ b/routes/w3c/index.ts
@@ -1,9 +1,14 @@
 import { Router } from "express";
 import cors from "cors";
 
+import authGithubWebhook from "../../utils/auth-github-webhook.js";
+import { env } from "../../utils/misc.js";
+
 import groupsRoute from "./group.js";
+import updateRoute from "./update.js";
 
 const w3c = Router();
 w3c.get("/groups{/:shortname}{/:type}", cors(), groupsRoute);
+w3c.post("/update", authGithubWebhook(env("W3C_GROUPS_SECRET")), updateRoute);
 
 export default w3c;
diff --git a/routes/w3c/update.ts b/routes/w3c/update.ts
new file mode 100644
index 00000000..80e59bcc
--- /dev/null
+++ b/routes/w3c/update.ts
@@ -0,0 +1,28 @@
+import path from "path";
+
+import { Request, Response } from "express";
+
+import { BackgroundTaskQueue } from "../../utils/background-task-queue.js";
+
+import { reloadGroups } from "./group.js";
+
+const workerFile = path.join(import.meta.dirname, "update.worker.js");
+const taskQueue = new BackgroundTaskQueue<typeof import("./update.worker.ts")>(
+  workerFile,
+  "w3c_groups_update",
+);
+
+export default async function route(_req: Request, res: Response) {
+  const job = taskQueue.add();
+  try {
+    const { updated } = await job.run();
+    if (updated && !reloadGroups()) {
+      res.status(500);
+    }
+  } catch {
+    res.status(500);
+  } finally {
+    res.locals.job = job.id;
+    res.send(job.id);
+  }
+}
diff --git a/routes/w3c/update.worker.ts b/routes/w3c/update.worker.ts
new file mode 100644
index 00000000..fd7d8801
--- /dev/null
+++ b/routes/w3c/update.worker.ts
@@ -0,0 +1,11 @@
+import w3cGroupsScraper from "../../scripts/update-w3c-groups-list.js";
+
+export default async function w3cGroupsUpdate() {
+  try {
+    await w3cGroupsScraper();
+    return { updated: true };
+  } catch (error) {
+    console.error("W3C groups update failed:", error);
+    return { updated: false };
+  }
+}