Webhook Testing: How to Debug, Inspect, and Replay Webhooks in 2026

Webhook Testing: How to Debug, Inspect, and Replay Webhooks in 2026 What is a Webhook? A webhook is an HTTP POST request sent from one service to another when an event happens. Your server receives it and reacts. Stripe event happens (payment.success) → POST https://yoursite.com/api/webhook/stripe → Your server processes it Testing Webhooks Locally Step 1: Expose Localhost # ngrok (free tier) ngrok http 3000 # cloudflared (Cloudflare, free) cloudflared tunnel --url http://localhost:3000 # Both give you a public URL like: # https://abc123.ngrok.io Step 2: Register the Webhook In your service dashboard (Stripe, GitHub, Slack): Payload URL : https://abc123.ngrok.io/api/webhook/handler Events : payment_intent.succeeded, payment_intent.failed Verifying Webhook Signatures Always verify signatures. Never trust the payload blindly. // Express.js webhook handler with Stripe signature verification const express = require ( ' express ' ); const crypto = require ( ' crypto ' ); const app = express