Syncing Webflow Native Forms to HubSpot Without Dropping Custom Form Data

Pavel Vainshtein

Founder @ WebflowForge | Driving Growth with Web Development & AI Automations

With over 9+ years of experience building scalable web platforms and digital products. I specialize in Webflow, WordPress, automations, AI solutions, and RevOps—combining UX, development, and business logic to create high-performing, conversion-focused systems. I help with UI/UX, advanced integrations, CMS/database architecture, and full platform builds. From idea to execution, I turn concepts into production-ready, lead-generating machines built for growth, performance, and scale.

Hubspot

Webflow

Make

Syncing Webflow Native Forms to HubSpot Without Dropping Custom Form Data

19th May, 2026

Table of content:

Syncing Webflow Native Forms to HubSpot Without Dropping Custom Form Data
The Problem We’re Solving
The Hidden "Gotcha" (What usually breaks)

Most marketing teams hit a wall when they try to move custom Webflow form data into HubSpot. If you use native integrations, you're stuck with basic fields. If you use a simple Zapier setup, multi-select checkboxes or custom radio buttons often pass raw, unformatted strings that cause HubSpot to reject the entire payload.

This blueprint fixes that by using a custom webhook setup in Make.com to sanitize and map complex Webflow lead data cleanly into HubSpot custom properties.

The Stack

Frontend: Webflow Native Forms
Middleware: Make.com (Custom Webhook + Data Router)
Destination: HubSpot CRM

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The Problem We’re Solving

When a user selects multiple services or industries on a Webflow form, Webflow outputs this data as a comma-separated text string or a raw array. HubSpot expects a semi-colon-separated string (Value1;Value2;Value3) for multi-select fields. When the data structures mismatch, your sales pipeline gets messy, leads stall, and attribution breaks.

The Setup Strategy

Ditch the native HubSpot block in Webflow: Submit your form natively to Webflow's form handler or send it directly to a Make.com custom webhook URL via a tiny piece of JavaScript.
The Make.com Array Transformation: We use a join() and split() function in Make to convert Webflow's text output into HubSpot’s strict multi-select format.
Upsert Logic: Instead of just creating a new contact (which creates duplicates), we search HubSpot by email first. If the contact exists, we update the profile and log the new form submission as a Timeline Event; if not, we create a clean record.

Webflow make and hubspot integration flow — Full workflow

Want to apply this to your setup?

Tell us about your stack and we’ll break down how this playbook would work for you.

The Hidden "Gotcha" (What usually breaks)

If a user submits a form and accidentally leaves a required HubSpot dropdown empty, the Make scenario will throw a 400 Bad Request error and halt your pipeline. To prevent this, always add a Data Filter right before the HubSpot module to check if essential string lengths are greater than zero, or use a switch() formula to apply fallback default values.

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Want this built for you?

Webflowforge offers Webflow HubSpot integration for service companies and SaaS teams. Prefer to skip the setup? Tell us about your project and we'll scope it with you.