Webflow Form Lead to Klaviyo (Signed Webhook) n8n Workflow

Turn Webflow Form Leads into Klaviyo Subscribers (with signed webhook security)

This Webflow Form Lead to Klaviyo (Signed Webhook) n8n workflow receives Webflow form submissions, verifies the Webflow HMAC signature to prevent spoofing or replay attacks, then creates/updates the contact in Klaviyo and subscribes them to your selected list.

What this workflow does

• Receives Webflow submissions via a POST webhook request containing the form submission payload.
• Validates request authenticity by verifying the Webflow HMAC signature and timestamp—rejecting invalid or replayed requests.
• Extracts lead details (submitter’s email and name) and builds Klaviyo API request bodies for a profile upsert and list subscription.
• Upserts the Klaviyo profile using the Klaviyo Profiles API to create or update the contact.
• Adds the contact to a Klaviyo list via the Klaviyo Subscriptions API, including email marketing consent as defined in the workflow.
• Acknowledges the webhook by returning a JSON response with HTTP 200.

Use cases

• Capture leads from a Webflow landing page and automatically add them to the right Klaviyo audience.
• Keep your Klaviyo profiles current by upserting details whenever a user submits another form.
• Improve security for lead ingestion by ensuring only correctly signed Webflow requests are processed.
• For SaaS operators: route every Webflow form submission to Klaviyo for onboarding and marketing follow-up.

Technical details (n8n + APIs)

• n8n nodes/tools: Webhook, Code, HTTP Request, Respond to Webhook
• Integrations: Webflow (signed webhook submissions) and Klaviyo (Profiles API + Subscriptions API)
• Required setup: paste your Webflow App Client Secret into signature verification code; add your Klaviyo Private API Key as HTTP header auth on both Klaviyo requests; update the Klaviyo List ID in the payload-mapping code.