JSON Webhook Tester

Send test JSON webhook payloads to any endpoint — with templates for Stripe, GitHub, Slack, and more

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Sent as X-Webhook-Event header

If provided, an X-Hub-Signature-256 header is computed from the payload + secret

Response

Configure your webhook payload and click Send Webhook

What Is a Webhook?

A webhook is an HTTP callback — a way for one system to send real-time data to another system when a specific event occurs. Unlike traditional APIs where you poll for data, webhooks push data to you automatically. Common examples include Stripe sending payment events, GitHub notifying you of code pushes, and Slack posting messages to channels.

When testing webhook integrations, you need to send sample payloads to your endpoint to verify handling, parsing, and response. This tool lets you craft and send those test payloads with the right headers and signatures.

How to Use

  1. Enter the webhook URL — The endpoint your service exposes to receive webhooks.
  2. Set the event type (optional) — Sent as the X-Webhook-Event header to help your handler identify the event.
  3. Compose the JSON payload — Write your JSON or load a template to get started quickly.
  4. Add custom headers — Include any webhook-specific headers your service expects (e.g., X-Hub-Signature, X-Stripe-Signature).
  5. Set a signing secret (optional) — Automatically computes an X-Hub-Signature-256 HMAC header.
  6. Click Send Webhook — The payload is sent via our proxy and the response is displayed.

Common Webhook Events

Stripe

  • charge.succeeded
  • payment_intent.succeeded
  • invoice.paid
  • customer.subscription.updated
  • checkout.session.completed

GitHub

  • push
  • pull_request
  • issues
  • release
  • workflow_run

Slack / Discord

  • Incoming Webhook (message)
  • Slash Command
  • Interaction (buttons, modals)
  • Message (Discord)
  • Interaction (Discord)

FAQs

How is this different from the API Request Builder?

The API Request Builder is a general-purpose HTTP client. This tool is specifically designed for webhook testing — it includes event type headers, HMAC signature generation, and ready-to-use templates for popular services like Stripe, GitHub, Slack, Discord, and Zapier.

What is the X-Hub-Signature-256 header?

It's an HMAC-SHA256 signature of the request body, computed using your webhook secret. Many services (like GitHub and Stripe) use similar signatures to verify that webhook requests are legitimate and haven't been tampered with.

Can I test local webhook endpoints?

No. The proxy cannot reach localhost or private network addresses. For local testing, consider using the cURL Builder to generate curl commands you can run locally, or use a tool like ngrok to expose your local server.

Frequently Asked Questions

What does this tool do?

This tool helps web developers build, test, and debug common web components and configurations directly in their browser.

How do I use this tool?

Configure your options and click the generate or process button. The output is displayed and can be copied or downloaded.

Is my data sent to a server?

No. All processing is performed locally in your browser. Your data never leaves your device.

Can I use the output in production?

Yes, but always review and test the output for your specific requirements before deploying to production.

Is this tool free to use?

Yes. This tool is completely free with no usage limits or registration required.

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