Lead Capture Form API — Free Endpoint for Any Website

A lead capture form API is a hosted endpoint your lead form submits to instead of a backend you build yourself. splitforms is that endpoint — POST your form to https://splitforms.com/api/submitwith a hidden access_key and it stores the lead, filters spam, and emails your team instantly. It works with a plain HTML form action or a fetch() call that sends JSON, and it's free for up to 500 leads a month.

Need a different lead type instead? See lead capture form templates for demo requests, waitlists, and lead magnets.

Lead Form Code (Copy & Paste)

<form action="https://splitforms.com/api/submit" method="POST">
  <input type="hidden" name="access_key" value="YOUR_KEY">
  <input type="hidden" name="subject" value="New Lead from Website">

  <input type="text" name="name" placeholder="Full Name" required>
  <input type="email" name="email" placeholder="Work Email" required>
  <input type="text" name="company" placeholder="Company">
  <select name="company_size">
    <option value="">Company Size</option>
    <option value="1-10">1-10</option>
    <option value="11-50">11-50</option>
    <option value="51-200">51-200</option>
    <option value="200+">200+</option>
  </select>
  <textarea name="message" placeholder="What do you need?" required></textarea>

  <input type="checkbox" name="botcheck" style="display:none" tabindex="-1" autocomplete="off">
  <button type="submit">Get My Quote</button>
</form>

Submit Leads as JSON (Fetch API)

Building the form yourself in React or Next.js, or capturing leads from a mobile app or backend job? POST JSON to the same endpoint instead of submitting an HTML form. See the React form guide or the Next.js form guide for framework-specific examples.

// Submit a lead as JSON — from a SPA, mobile app, or serverless function
await fetch("https://splitforms.com/api/submit", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({
    access_key: "YOUR_ACCESS_KEY",
    form_loaded_at: pageLoadedAt, // timestamp set when the page/form loaded
    name: "Jane Doe",
    email: "jane@company.com",
    company: "Acme Inc.",
    message: "Interested in the Pro plan",
    botcheck: ""                  // honeypot — must stay empty
  })
});

How to Connect a Lead Capture Form to the API

1. Step 1

   Get a free access key

   Sign up free and build your form in the drag-drop dashboard, or just copy the HTML below. splitforms generates the access_key automatically — no card required.

2. Step 2

   Add the required hidden fields

   access_key identifies which form a submission belongs to. An empty botcheck honeypot and a form_loaded_at timestamp power the spam filtering — leave botcheck blank and set form_loaded_at when the page loads.

3. Step 3

   Point the form at the endpoint

   Set the HTML form's action to https://splitforms.com/api/submit with method POST — or POST a JSON body from your own code with the same fields. Multipart is supported for file uploads.

4. Step 4

   Send one real test lead

   Submit it and confirm it lands in the dashboard and your inbox. Email notifications to the form owner are free on every plan, including Free.

5. Step 5

   Control what happens next

   Use subject to customize the notification email's subject line, redirect to send the visitor to a thank-you page, and replyto so you can reply straight to the lead.

6. Step 6

   Route leads further

   On Starter ($1/mo) and above, add a signed webhook or a native integration — Google Sheets, Notion, Airtable, Slack, Discord, Telegram, WhatsApp, or Mailchimp — so leads move without anyone checking the dashboard.

Full details on rate limits, reserved field names, and the spam stack live in the spam protection docs. Compare plan limits — Free at 500/mo up to Business unlimited — on the pricing page.

Send Leads to Your CRM

On Starter ($1/mo) and above, every lead triggers a signed webhook. Forward leads to:

• Salesforce — create new leads automatically
• HubSpot — add contacts to your pipeline
• Pipedrive — create deals from form submissions
• Mailchimp — add subscribers to your list
• Slack — get instant lead notifications
• Google Sheets — append leads as rows

Mailchimp, Slack, and Google Sheets are native one-click integrations — no webhook needed. Salesforce, HubSpot, and Pipedrive connect through a signed webhook — point it directly at a receiving URL, or route it through Zapier, Make, or n8n. See how form-to-webhook delivery works, including the HMAC-SHA256 signature format, in sending form data to a webhook.

FAQ

Questions? Email hello@splitforms.com