Webhook Tester
Get a temporary URL and inspect the headers and body of every webhook sent to it.
Slack & Discord Webhook Message Tester
Compose an alert message, preview it and send it to a Slack incoming webhook or a Discord channel webhook. Copy the JSON or the curl command for your scripts.
- Free
- No sign-up
- Runs in your browser
Messages go straight from your browser to Slack or Discord. The URL isn’t stored or sent to SensaCat.
Preview
An approximate preview. Slack and Discord each render formatting a little differently.
JSON payload
curl
How to use the Slack & Discord Webhook Tester
- Choose Slack or Discord and paste the incoming webhook URL.
- Write the message, and add a title, colour or fields.
- Check the preview and the generated JSON.
- Send a test message, or copy the curl command.
Catch webhooks that never arrive
SensaCat tracks each step of a business flow (payment, order, fulfilment) and alerts you when an expected event doesn’t show up in time.
Frequently asked questions
Create a Slack app, turn on Incoming Webhooks and add a webhook to a channel. The URL starts with https://hooks.slack.com/services/.
In Discord, open the channel settings, go to Integrations, then Webhooks, and create a webhook. Copy its URL, which starts with https://discord.com/api/webhooks/.
Slack’s webhook endpoint doesn’t let browsers read its response, so the tester sends the message but can’t see whether Slack accepted it. Check the channel, or run the curl command to see the response.
Yes. Anyone with the URL can post to your channel. Store it as a secret, and regenerate it if it leaks.
Related tools
JSON Formatter
Pretty-print, minify and validate JSON with exact line and column errors.
Webhook Retry Calculator
See when each retry fires with exponential backoff and jitter, and what survives an outage.