# Discord Webhook Tester

> Free open-source Discord webhook tester: send a test message from the CLI or a local web form, build embeds with a live preview, export as JSON or curl.

Source: https://webhooker.eu/tools/discord-webhook-tester
Last updated: 2026-09-18

[Open-source tools](https://webhooker.eu/tools) / Discord Webhook Tester

Discord Webhook Tester checks that a Discord webhook works and helps you design the message it posts. Use the CLI in scripts and CI, or run the web form to build embeds visually with a live preview. It runs on your own machine, so the webhook URL, which is a credential, never reaches a third-party website.

- Python
- MIT licensed
- Docker image
- No account

[View on GitHub](https://github.com/webhooker-eu/discord-webhook-tester) Quick start

## What Discord Webhook Tester does

Two things: it proves the webhook is alive, and it shows you what your message will look like before a channel full of people sees it.

| Feature | What it means |
| --- | --- |
| One-command test | `discord-webhook-tester send` posts a ready-made test embed, with no options to fill in. |
| Embed builder | Title, description, colour, author, fields, images, footer and timestamp, as CLI options or in the form, up to 10 embeds per message. |
| Live preview | The form renders your draft the way Discord will, and sent messages land in the mock channel with their delivery status. |
| Export | Copy the same message as a JSON payload, a `curl` command or a CLI command. |
| Local validation | Discord's limits are checked before anything is sent, so a typo fails instantly instead of after a round trip. |
| Readable errors | Nested Discord error responses become lines like `embeds.0.title: Must be 256 or fewer in length.` |
| Threads, forums, files | Post into a thread, create a forum post, attach files, or send without notifications. |

## Quick start

Run it without installing anything, using [uv](https://docs.astral.sh/uv/):

```bash
export DISCORD_WEBHOOK_URL='https://discord.com/api/webhooks/<id>/<token>'

uvx --from git+https://github.com/webhooker-eu/discord-webhook-tester \
  discord-webhook-tester send
```

Or install it as a command:

```bash
uv tool install git+https://github.com/webhooker-eu/discord-webhook-tester
# or
pipx install git+https://github.com/webhooker-eu/discord-webhook-tester

discord-webhook-tester send
```

Or run the published image, with nothing else on your machine:

```bash
# Web form on http://localhost:8080
docker run --rm -p 127.0.0.1:8080:8080 ghcr.io/webhooker-eu/discord-webhook-tester

# Or as the CLI
docker run --rm -e DISCORD_WEBHOOK_URL ghcr.io/webhooker-eu/discord-webhook-tester \
  send --content 'Hello from Docker'
```

Get the webhook URL in Discord under **Server Settings → Integrations → Webhooks → New Webhook → Copy Webhook URL**. Prefer the `DISCORD_WEBHOOK_URL` variable over passing it as an argument: arguments end up in your shell history.

## Building an embed from the CLI

Every part of a Discord embed has an option, so a deploy notification is one command in your pipeline:

```bash
discord-webhook-tester send \
  --title 'Build #128 passed' \
  --description 'All **42** tests are green.' \
  --url 'https://ci.example.com/builds/128' \
  --color green \
  --author 'CI' \
  --field 'Branch|main|inline' \
  --field 'Duration|3m 12s|inline' \
  --footer 'ci.example.com' \
  --timestamp now
```

Colours accept `#RRGGBB`, a decimal integer or a name such as `blurple`, `green` or `red`. Fields take `'NAME|VALUE|inline'` and repeat up to 25 times. A raw payload from a file or stdin works too, with `--payload-file`, and any other options are layered on top of it.

## The web form

`discord-webhook-tester serve --open` starts a local form on `127.0.0.1:8080`. Paste the webhook URL, build the message, press **Send message**, and read what Discord answered. The draft is kept in your browser's local storage; the webhook URL is stored only if you tick **Remember the URL in this browser**.

## Using it in CI

The CLI is built for scripts: it reads the URL from an environment variable, prints JSON on request, and returns an exit code you can branch on.

```bash
# Confirm the webhook still exists, without posting anything
discord-webhook-tester info --json || echo 'The Discord webhook is broken'

# See the JSON that would be sent
discord-webhook-tester send --title 'Hello' --color '#5865F2' --dry-run
```

| Exit code | Meaning |
| --- | --- |
| `0` | The message was sent, or the webhook is valid. |
| `1` | Discord rejected the request, or could not be reached. |
| `2` | Invalid input: a bad URL, a payload over Discord's limits, an unreadable file. |

## Discord webhooks and the rest of your webhook traffic

A Discord webhook is an outgoing notification: your script posts a message and Discord shows it. That is the opposite direction from the webhooks a provider sends you, where a missed request means a missed payment or a missed order. If you also relay provider events into a Discord channel, the fragile part is not the message. It is whether the event reached your code at all.

[Webhooker](https://webhooker.eu/) handles that half: one ingest URL receives the provider's events, verifies the signature, stores each one and delivers it to your services with retries and replay. Start with [what a webhook is](https://webhooker.eu/blog/what-is-a-webhook) if the two directions still blur together.

## Frequently asked questions

### How do I test a Discord webhook?

Copy the webhook URL from Server Settings, Integrations, Webhooks, then run discord-webhook-tester send with DISCORD_WEBHOOK_URL set. A ready-made embed is posted to the channel, and the exit code tells you whether Discord accepted it. No message is sent by the info command, which only confirms that the webhook exists and shows its name, channel and server.

### Where do I find my Discord webhook URL?

In Discord: Server Settings, then Integrations, then Webhooks, then New Webhook and Copy Webhook URL. It looks like https://discord.com/api/webhooks/<id>/<token>. Treat it as a credential: anyone who has it can post to that channel, so keep it in an environment variable rather than in code or shell history.

### Can I build an embed without writing JSON?

Yes. Run discord-webhook-tester serve to open a local web form that looks like a Discord channel: set the title, description, colour, author, fields, images, footer and timestamp, and the preview renders the message as Discord will show it. The JSON, curl and CLI tabs give you the same message in a form you can paste into your code.

### Why is Discord rejecting my webhook message?

Usually a limit: 2000 characters of content, 6000 characters across all embeds, 25 fields per embed, 10 embeds per message. The tool checks those locally before sending, and turns Discord's nested error response into one line per problem, such as embeds.0.title: Must be 256 or fewer in length. A 404 means the webhook was deleted; a 401 means the token in the URL is wrong.

### Does the webhook URL leave my machine?

Only to Discord. The CLI and the local server parse the URL into an id and a token and rebuild the request from those parts, so nothing is sent anywhere else, and the form stores the URL in your browser only if you tick the box. That is the difference from pasting a webhook URL into a public tester website.

### Can I use it in CI?

Yes. It reads the URL from an environment variable, prints machine-readable output with --json, and returns 0 only when Discord accepted the request, so a pipeline step can fail on a broken webhook. Files, threads, forum posts and silent messages are supported for the notification itself.

## Further reading

- [What is a webhook? Definition, payloads and use cases](https://webhooker.eu/blog/what-is-a-webhook)
- [How webhooks work: the request, header by header](https://webhooker.eu/blog/how-do-webhooks-work)
- [Webhook security: signatures, replays and secrets](https://webhooker.eu/blog/webhook-security-signature-verification)

## More open-source tools

[Webhook Tester  →   Self-hosted request bin in one Docker container.](https://webhooker.eu/tools/webhook-tester)[Webhook Mock Sender  →   Send signed Stripe, GitHub and Shopify events to your own endpoint.](https://webhooker.eu/tools/webhook-mock-sender)

Everything we publish lives in the [webhooker-eu GitHub organisation](https://github.com/webhooker-eu), and the full list with a short description of each is on the [open-source tools page](https://webhooker.eu/tools).

## When the testing is done, the events still have to arrive.

Webhooker is the hosted side of the same problem: one EU-hosted ingest URL for any provider, signatures verified before a payload is accepted, every event stored, retried and replayable. Free for 10,000 events a month.

[Start for free](https://app.webhooker.eu/register) [Read the docs](https://webhooker.eu/docs)