Slack Block Kit JSON Builder

Assemble Slack messages visually and export Block Kit JSON.

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Assemble a Slack message visually and export Block Kit JSON for the chat.postMessageAPI or an incoming webhook.

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Block Kit JSON

{
  "blocks": [
    {
      "type": "header",
      "text": {
        "type": "plain_text",
        "text": "🚀 Deploy complete",
        "emoji": true
      }
    },
    {
      "type": "section",
      "text": {
        "type": "mrkdwn",
        "text": "*Service:* api-gateway\n*Version:* v2.4.1"
      }
    },
    {
      "type": "divider"
    },
    {
      "type": "actions",
      "elements": [
        {
          "type": "button",
          "text": {
            "type": "plain_text",
            "text": "View logs"
          },
          "url": "https://example.com/logs"
        }
      ]
    }
  ]
}

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About Slack Block Kit JSON Builder

Slack Block Kit JSON Builder is a free Slack tool that lets you build a ready-to-send webhook payload — no guesswork, no docs. Copy the JSON and paste it straight into Slack or your Slack app config. It runs entirely in your browser with no sign-up and no installs, so your data stays private.

How to use Slack Block Kit JSON Builder

1Open Slack Block Kit JSON Builder — it loads instantly and runs entirely in your browser.
2Fill in the fields with your own values; the output updates live as you type.
3Review the generated JSON in the preview area.
4Copy the JSON and paste it straight into Slack or your Slack app config.

Why use Slack Block Kit JSON Builder?

✓Generates a valid JSON in seconds — no copy-pasting from docs
✓100% client-side: your inputs never leave your browser
✓Free and unlimited — no account, no trial, no credit card
✓Works on desktop and mobile; copy or download the JSON instantly

Frequently asked questions

Is Slack Block Kit JSON Builder free?+

Yes. Slack Block Kit JSON Builder is completely free with no account, no trial and no usage limits. ToolJolt is supported by unobtrusive ads, not paywalls.

Where do I paste the output from Slack Block Kit JSON Builder?+

Click Copy, then paste the JSON into Slack or your Slack app config. Each tool's preview shows exactly what to add and where, so you can drop it in and save without reading the docs.

Is my data private?+

Completely. Slack Block Kit JSON Builder runs 100% in your browser (client-side). Nothing you type is uploaded to a server, so your data stays on your device.

Do I need to sign up or install anything?+

No. There's nothing to install and no sign-up — just open the page and start. It works on desktop and mobile.

Do I need to be a Slack admin?+

For most outputs, no — you can paste messages, reminders and Block Kit straight into Slack. Installing apps or custom emoji may require workspace admin rights.

Can I use the output commercially?+

Yes. The configuration, code or files you generate are yours to use in personal and commercial projects without attribution.

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