How can I incorporate promo codes into my Webflow Free Trial landing page and display an error message for invalid codes? Can this be done without custom code and how can I maintain a database of valid promo codes for successful form submissions?

You’re trying to add promo code functionality to a Webflow landing page, validate codes, and show errors for invalid ones—all preferably without using custom code. Here’s how this works with current Webflow limitations.

1. Understand Webflow’s Native Limitations

• Webflow Forms by themselves do not support conditional logic or real-time validation of promo codes stored in a database.
• No built-in Promo Code database or form field validation system exists.
• You cannot perform real-time logic (like checking if a code exists) without using custom code or an external integration.

2. Use Third-Party Integration (Zapier or Make)

• Use Zapier or Make (Integromat) to handle form submissions and validate promo codes against a Google Sheet or Airtable database.
• Steps:
• Create a promo code list in Google Sheets or Airtable (e.g., one column for valid codes).
• Set up a Zap/Scenario: When form data is submitted from Webflow, check the submitted promo code against your data.
• If valid: proceed (e.g., send a confirmation email or tag the user).
• If invalid: send a rejection email or notification.

Note: You still can't show an error instantly on the Webflow page itself without JavaScript.

3. Option: Add Custom Code for In-Page Validation

• To show instant error handling (like "Invalid code") without reloading the page, custom JavaScript is required.
• You’d need to:
• Store valid codes as a JS array directly in the page or make a fetch request to a hosted JSON file.
• Use input event listeners to validate the code in real-time or on form submit.
• Show/hide validation messages using Webflow's interactions or visibility toggles.

This approach requires moderate JavaScript knowledge.

4. Workaround Without Custom Code (Not Recommended for Security)

• You could technically build a Form Select dropdown with predefined codes, but:
• This exposes all codes publicly.
• Cannot handle dynamic validation.
• Offers no rejection feedback—it’s limited and insecure.

5. Maintaining the Promo Code Database

• Use a Google Sheet or Airtable base as your centralized promo code list.
• Make sure the integration tool (Zapier or Make) connects to this source.
• Add logic to mark codes as “used” or “inactive” after validation, if needed.

Summary

Webflow alone cannot validate promo codes on form submission or show errors for invalid entries. To implement this:

• Use Zapier or Make to check submitted codes against a Google Sheet or Airtable.
• Add custom JavaScript if you want immediate error messages on the page.
• Maintain promo codes in a simple sheet and connect it via automation tools.

For full validation and error feedback without page reloads, custom code is required.