Slack Unfurl Playground

Each link below is a page that emits a specific combination of OpenGraph and Twitter-card meta tags. Paste any of them into a Slack channel to see how Slack chooses to render the unfurl.

How to use

1. Deploy to Vercel (see README).
2. Paste a variant URL into a Slack channel.
3. Slack caches unfurls aggressively — append ?v=2 (or any changed query string) when you want a fresh render.

Variants

• OpenRouter replica
  Mirrors openrouter.ai/google/gemini-2.5-flash exactly — same OG + Twitter card structure, same description format.
  /v/openrouter-replica
• Twitter card: summary_large_image
  The big-image card layout — Slack renders a hero image above the text.
  /v/summary-large-image
• Twitter card: summary (small thumb)
  The compact card. Slack should render a small square thumbnail next to the text.
  /v/summary-small
• No image
  Title + description only. Slack renders the text-only unfurl (no image strip).
  /v/no-image
• OpenGraph only (no Twitter tags)
  Tests Slack's OG-only fallback. No twitter:* tags are emitted.
  /v/og-only
• Twitter tags only (no OG)
  Tests Slack's Twitter-card fallback when OG tags are absent.
  /v/twitter-only
• Very long title
  Sees where Slack truncates titles. ~140 chars here.
  /v/long-title
• Very long description
  Description is ~600 characters — Slack typically truncates around 300. Useful for seeing the cutoff.
  /v/long-description
• Tall (portrait) image
  600×900 image. Slack typically letterboxes or rejects.
  /v/tall-image
• Tiny image (below Slack's threshold)
  200×200 image. Slack often refuses to render images below ~250px and falls back to text.
  /v/tiny-image
• og:type=article
  Article type with author + published time. Some clients show extras for these.
  /v/article
• OpenRouter replica — image stripped
  Same as openrouter-replica but with the og:image / twitter:image removed, to isolate whether the image is what's driving the card layout.
  /v/openrouter-no-image

Custom one-off

/custom accepts query parameters and renders them as meta tags. Useful for quick one-off experiments without editing the variants list.

Supported /custom params

• title, description
• image, image_width, image_height
• card = summary | summary_large_image
• site_name, creator, type