Google Forms Slack webhook setup

• A Slack incoming webhook URL for the channel you want messages to land in. Looks like https://hooks.slack.com/services/T.../B.../XXX. Create one inside Slack on the channel you pick.
• A Google Formwith at least one question. You'll attach an Apps Script to it that POSTs every response to the webhook.

1. 1
   In Slack, open the channel you want to receive messages

   Click the channel name → Integrations → Add an app.
2. 2
   Search for 'Incoming Webhooks' and install (if needed)

   If your workspace doesn't already have it installed, Slack walks through approving it.
3. 3
   Add a new webhook for that channel

   Slack generates a unique URL bound to the channel you picked. Copy it.
4. 4
   Treat the URL like a password

   Anyone with the URL can post to that channel as the webhook's app. Don't paste it into shared documents.

Open your Google Form. Click the three-dot menu (top-right) → Apps Script. Delete the placeholder code and paste this, replacing WEBHOOK_URL with the URL you copied:

const WEBHOOK_URL = "PASTE_YOUR_WEBHOOK_URL_HERE";

function installFormBridge() {
  var form = FormApp.getActiveForm();
  // Wipe any existing onFormSubmit trigger so re-running install is safe.
  var existing = ScriptApp.getProjectTriggers();
  for (var i = 0; i < existing.length; i++) {
    if (existing[i].getHandlerFunction() === "onFormSubmit") {
      ScriptApp.deleteTrigger(existing[i]);
    }
  }
  ScriptApp.newTrigger("onFormSubmit").forForm(form).onFormSubmit().create();
  Logger.log("Installed.");
}

function onFormSubmit(e) {
  var form = FormApp.getActiveForm();
  var response = e.response;
  var items = response.getItemResponses();
  var lines = [];
  for (var i = 0; i < items.length; i++) {
    var title = items[i].getItem().getTitle();
    var answer = items[i].getResponse();
    if (Array.isArray(answer)) answer = answer.join(", ");
    lines.push("*" + title + ":* " + answer);
  }
  var payload = {
    text: "New response from " + form.getTitle(),
    blocks: [
      { type: "section", text: { type: "mrkdwn", text: ":inbox_tray: *New form response*" } },
      { type: "section", text: { type: "mrkdwn", text: "*Form:* " + form.getTitle() } },
      { type: "divider" },
      { type: "section", text: { type: "mrkdwn", text: lines.join("\n") } }
    ]
  };
  UrlFetchApp.fetch(WEBHOOK_URL, {
    method: "post",
    contentType: "application/json",
    payload: JSON.stringify(payload),
    muteHttpExceptions: true
  });
}

Save the script with ⌘S. In the function dropdown at the top of the editor, choose installFormBridge and click Run. Google will ask you to authorise the script the first time, click Advanced → Go to ... (unsafe) → Allow. The warning is because the script is unverified, not because it's actually unsafe; it's your script and you can read every line.

Don't want to copy this by hand? Our free Apps Script generator emits the same script with your webhook URL pre-filled, plus a TEST_MODE toggle for dry-running.

Open your Google Form and fill it in. Within a few seconds, you should see a Slack message in the channel the webhook is bound to.

If nothing arrives: open the Apps Script editor again, click Executions in the left sidebar, and look for the most recent onFormSubmitrun. Failures show the HTTP status and Slack's response. Common ones:

• HTTP 404 / “no_service”: the webhook URL is wrong or has been revoked. Create a new one.
• HTTP 403 / “invalid_token”: Slack rejected the request. Re-create the webhook.
• HTTP 400 / “invalid_payload”: the JSON shape is off; check the script wasn't edited.

Our free webhook checker POSTs a test payload to any HTTPS URL and translates Slack's opaque error codes into plain English. Useful for narrowing down the failure without leaving the browser.

For one form, one channel, one developer, the script above is plenty. Where it starts hurting:

• Multiple channels by answer. Adding IF-THEN routing inside the script is writing a tiny custom routing engine. Maintainable for one person; opaque to the rest of the team.
• Retries that don't double-post. Apps Script retries on transient errors without dedupe. Slack can show duplicate messages. Fixing this means storing the response ID somewhere and checking it before each post.
• Delivery audit log.Apps Script's Executions log is engineer-facing and ephemeral. Showing a teammate or client “here's the actual Slack response code we got” needs purpose-built tooling.
• Multiple forms or multiple clients. The script lives inside one form. To run this for 10 forms, you maintain 10 scripts. To run it for 10 clients with their own webhooks, you maintain 10 sets of credentials in 10 separate forms.
• When the form question gets renamed. The script reads question titles. A renamed question silently breaks the rule that depended on it.

RouteForms is the managed version of this hop. Same Apps Script idea, except the script POSTs to a RouteForms webhook (we generate it pre-filled), and RouteForms does the routing, dedupe, log, and retry on its end.

• IF-THEN routing rules in a dashboard, with 10 operators and a live simulator
• Idempotency on the Google Forms response ID, retries can't double-post
• Per-form delivery log with Slack's HTTP response code
• One-click retry on failed deliveries
• Failed-delivery email alerts on paid plans
• Client workspaces for agencies on the Agency plan
• Free for 30 responses a month, $7/month for unlimited

The migration is the same Apps Script swap: paste a new pre-filled script (we generate it inside your account), run it, done. Detailed walkthrough on the main guide and the without-Zapier migration page.