Images that don't meet platform requirements may be cropped incorrectly, rejected, or displayed at poor quality.

Each platform has different specifications. Make sure your image meets Slack's requirements shown below.

Open Graph tags control how your content appears when shared on social media platforms like Facebook, Twitter, and LinkedIn.

Missing or incorrect tags can result in broken previews, missing images, or unappealing shares that reduce click-through rates.

When you share a link on Slack, it sends a server-side request, not a browser, to fetch the page's HTML and read the meta tags. This is the request it makes.

After reading the meta tags, Slack makes a separate request to download the image. Some platforms use a different User-Agent or Accept header for images.