Slack Open Graph Meta Tags & Specs
The exact Open Graph specifications for Slack previews. Learn the exact image dimensions, required meta tags, and best practices for perfect workspace link unfurling.
Updated December 2025 3 min read
Quick Answer
Slack reads standard Open Graph properties and heavily prioritizes the
og:site_name and twitter:image (if provided). Keep aspect ratios between 1.91:1 and 2:1. Slack will automatically compress files over 10MB but smaller is safer. Slack Image Specs
Recommended Size
1200 ร 630px
1:1 square images also display differently, rendering as side-thumbs.
File Limitations
Max 12MB
Formats: JPG, PNG, GIF
Required Meta Tags
Basic HTML
html
<!-- Essential Slack Tags -->
<meta property="og:site_name" content="Your Brand Name" />
<meta property="og:title" content="Your Page Title" />
<meta property="og:description" content="Your compelling description" />
<meta property="og:image" content="https://example.com/image.jpg" />
<meta property="og:url" content="https://example.com/page" />Nuxt 3
typescript
useSeoMeta({
ogSiteName: 'Your Brand Name',
ogTitle: 'Your Page Title',
ogDescription: 'Your compelling description',
ogImage: 'https://example.com/image.jpg',
ogUrl: 'https://example.com/page',
})Next.js
typescript
export const metadata = {
openGraph: {
title: 'Your Page Title',
description: 'Your compelling description',
images: [{
url: 'https://example.com/image.jpg',
width: 1200,
height: 630,
}],
url: 'https://example.com/page',
siteName: 'Your Brand Name',
type: 'website'
},
}Top 3 Best Practices
- Use a recognizable og:site_name. Slack bolds this at the top of the "unfurled" preview for context.
- Images should be strictly absolute URLs. Slackbot fails completely on root relative paths (e.g.
/images/cool.png). - Ensure quick TTFB limits. Slackbot times out internally if crawling your linked page takes too long. Setup CDN caching.
Troubleshooting
Preview Not Generating?
If your domain is new or Slackbot failed to fetch once, it may temporarily blacklist fetching your preview. The user usually has to enter `/url` or right click to force unfurl.
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