How to Test Supabase Webhooks
Supabase Database Webhooks trigger HTTP requests when INSERT, UPDATE, or DELETE operations happen on your tables.
Looking for the broader picture? See the 7 best webhook testing tools (2026), or if you're already on Webhook.site, the 60-second migration to HookRay.
Supabase Official Webhook Docs1. Supabase Webhook Events
Supabase can send the following webhook events to your endpoint:
INSERTUPDATEDELETE2. Set Up a Test Endpoint with HookRay
Follow these steps to start receiving Supabase webhooks for testing:
- Go to HookRay and click "Start Testing — Free" to get your unique webhook URL.
- Copy the URL (e.g.,
https://h.hookray.com/abc123). - In your Supabase dashboard, navigate to the webhook settings and paste the HookRay URL as your endpoint.
- Select the events you want to receive (see list above).
- Trigger a test event — HookRay will show the incoming webhook in real-time.
3. Sample Supabase Webhook Payload
Here's an example of what a Supabase webhook payload looks like:
{
"type": "INSERT",
"table": "users",
"record": {
"id": "uuid-1234",
"email": "new_user@example.com",
"created_at": "2026-03-18T00:00:00Z"
},
"old_record": null
}4. Frequently Asked Questions
How do I test Supabase webhooks without deploying?
Use HookRay to get an instant public webhook URL. Paste it into your Supabase dashboard's webhook configuration, trigger an event, and watch the payload arrive in real time. No code, no ngrok, no deployment required. The free tier captures 100 requests per month and works on all Supabase event types.
Why aren't my Supabase webhooks arriving?
The four most common causes: (1) the endpoint URL isn't publicly accessible — Supabase can't reach localhost; (2) the wrong events are subscribed in your Supabase dashboard; (3) signature verification is rejecting the request before your handler runs; (4) Supabase can't reach your server because of a firewall, expired SSL certificate, or wrong DNS. Use HookRay's URL to isolate which of these four is failing — if HookRay receives the webhook, the problem is in your handler. If HookRay doesn't, the problem is in Supabase configuration.
Why am I getting 400 or 500 errors from my Supabase webhook?
Supabase reports the response status your endpoint returned. HookRay accepts any payload and returns 200 OK by default, so if you see 400/500 in your Supabase dashboard while pointing at HookRay, the issue is in Supabase's configuration (wrong event, malformed signing secret, etc.). If you point at your own endpoint and get 400/500, the issue is in your handler — capture the request with HookRay, replay it locally, and debug from the captured payload.
How do I verify Supabase webhook signatures?
Supabase signs each webhook request with a shared secret. Capture the raw headers and body using HookRay, then verify the signature in your application using Supabase's SDK or a standard HMAC library. Once verification works against HookRay-captured data, you can safely deploy. Supabase's docs (linked above) cover the exact signing algorithm.
Can I replay a captured Supabase webhook?
Yes — HookRay's replay feature re-sends any captured webhook to a different endpoint with one click. This is the fastest way to fix a buggy handler: capture the payload once, fix your code, and replay until it works. No need to re-trigger the event in Supabase.
5. Next Steps
- Use HookRay's webhook replay feature to re-send captured webhooks while building your handler
- Enable smart parsing (Pro plan) to see Supabase-specific fields highlighted automatically
- Check the Supabase webhook documentation for the complete event reference
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Start Testing Supabase Webhooks — FreeFree PDF: Webhook Testing Cheat Sheet 2026
One-page reference for 50+ APIs — canonical events, signing methods, sample payloads. Print it, pin it, share it.
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