A webhook is an HTTP POST request sent automatically to a specified URL when a particular event occurs, enabling real-time data transfer between services without polling.
By Vaibhav Jain · Last updated March 27, 2026
Webhooks are the backbone of real-time integrations between web services. Instead of your application repeatedly checking (polling) another service for updates, the other service proactively sends you data the moment something happens.
In the context of form submissions, a webhook fires every time someone fills out your form. The form backend packages the submission data as a JSON payload and sends an HTTP POST request to a URL you configure. Your server receives this payload and can process it however you want — add the data to a CRM, trigger an email sequence, create a task in a project management tool, or store it in your own database.
Webhooks follow a simple pattern: event occurs, data is packaged, POST request is sent. The receiving server should respond with a 200 status code to acknowledge receipt. If the request fails, most webhook senders implement retry logic — they'll attempt delivery again after increasing intervals.
FormsList's webhook integration supports custom headers, retry with exponential backoff, and payload inspection in the dashboard. You can send form submissions to any HTTP endpoint — your own API, a serverless function, or a third-party service that accepts webhooks.
What is a webhook? A webhook is an automated HTTP POST request that a server sends to a pre-configured URL whenever a specific event occurs, enabling real-time, event-driven communication between two systems without the receiving system needing to continuously poll for updates. In the context of web forms, a webhook fires immediately after a form submission is received and processed, delivering the complete submission payload to any URL you specify — your own API server, a serverless function, a CRM endpoint, or a third-party automation platform.
The mechanics of a webhook are simple but powerful. When you configure a webhook on a form backend like FormsList, you provide a destination URL and optionally specify custom HTTP headers (such as an authorization token). Every time a new form submission arrives, the form backend serializes the submission data into a JSON payload — including all form fields, metadata like timestamp, IP address, and spam score — and sends an HTTP POST request to your URL. The receiving server processes the payload and returns an HTTP status code: a 2xx response means the delivery was successful, while a 4xx or 5xx response (or a timeout) triggers the retry mechanism. FormsList implements exponential backoff retries, attempting delivery up to five times over a 24-hour period to handle temporary failures. You can inspect every webhook delivery attempt — including the request payload, response status, and timing — directly in the FormsList dashboard.
Webhooks are the foundation of form-driven automation workflows. They let you connect form submissions to virtually any system that has an HTTP API. Common patterns include pushing leads to a CRM like Salesforce or HubSpot the instant they submit a form, posting notifications to team communication tools like Slack or Microsoft Teams, triggering email sequences in marketing platforms like Mailchimp or ConvertKit, creating tasks in project management tools like Asana or Linear, and writing submission data to your own database or data warehouse for custom processing. Without webhooks, these integrations would require either manual data entry or scheduled batch imports, both of which introduce delays and operational overhead.
A practical example: an e-commerce company uses FormsList to collect wholesale inquiry forms on their website. They configure a webhook that sends each submission to a Zapier webhook URL, which triggers a multi-step automation: the lead is added to their HubSpot CRM with a "wholesale" tag, a Slack message is posted to the #sales channel with the inquiry details, and a personalized follow-up email is sent via their email platform. The entire sequence executes within seconds of the form submission, with zero manual intervention. If the webhook delivery to Zapier fails due to a temporary outage, FormsList's retry mechanism ensures the data is delivered once the service recovers.
When a lead capture form is submitted, a webhook sends the data to your CRM's API endpoint, automatically creating a new contact record without manual entry.
A webhook sends form submission data to a Slack incoming webhook URL, posting a formatted message to a team channel every time someone fills out a form.
A webhook delivers form data to an AWS Lambda function that validates the submission, enriches it with third-party data, and stores it in DynamoDB.
Set up your form backend in under a minute. No server required, no complex configuration — just a simple endpoint for your forms.