What is causing the form submission error in Webflow?

A form submission error in Webflow typically occurs due to misconfiguration in your project settings, form setup, or browser-related issues.

1. Check if Form Submissions Work on the Published Domain

• Webflow forms only work on the domains listed in your Project Settings > Forms tab.
• If you're testing on a staging URL (e.g., customdomain.webflow.io), make sure that domain is added to the Form Submission Domain Whitelist.
• Using a site embedded via an iframe or hosted elsewhere can also block submissions unless configured correctly.

2. Ensure a Site Plan is Active

• Form submissions won’t work on custom domains (like yourdomain.com) unless you’ve purchased a Site Plan for that project.
• If you’re using a custom domain without a hosting plan, Webflow will block the form post request.

3. Double-Check Form Element Configuration

• Every form must contain a Form wrapper, at least one input field, and a submit button.
• Make sure input fields have unique “name” attributes (this is set automatically but can be modified).
• Remove any duplicate or empty forms that could confuse Webflow’s form submission handler.

4. Review Spam or ReCAPTCHA Settings

• If you’ve enabled ReCAPTCHA, ensure the proper site key and secret key are entered under Project Settings > Forms.
• Spam filtering may silently block submissions if forms are spammy or use reserved field names like "email" or "submit."

5. Network or JavaScript Errors

• Check the browser Console (Developer Tools) for any JavaScript errors or network status codes (like 403 or 405).
• Errors in form custom code (such as on-submit handlers) can interfere with Webflow’s native form submission logic.

6. Verify Redirects and Success/Error Pages

• If you’ve added a custom redirect URL after submission, validate that it’s a correct and allowed URL.
• Ensure you haven't removed or modified the Success and Error Message Blocks inside the form.

7. Check Daily Submission Limits (Forms on Webflow Hosting)

• Free Webflow hosting has a limit on daily form submissions (100 for Free Site Plans). Exceeding this will block submissions until limits reset.
• Go to Project Settings > Forms to view submission usage and export data.

Summary

Form submission errors in Webflow usually result from domain misconfigurations, missing hosting plans, JavaScript conflicts, or over-limit submissions. Verify your domain settings, form structure, and associated plan to resolve most issues.