Mastodon image sizes for link cards

Last checked: October 2026.

Recommended sizes for Mastodon. Based on how these apps render Open Graph images; no official spec is published.

Mastodon (and many ActivityPub clients) show a link card when a post includes a URL. Cards are built from public page metadata, typically Open Graph. Based on how these apps render Open Graph images; no single official Mastodon pixel spec is documented here yet. Design at 1200×630 with a short headline.

Recommended Mastodon size

Mastodon recommended image sizes
PlatformImage typeRecommended sizeAspect ratioMin sizeMax file size
MastodonRecommendedLink card1200 × 630 px1.91:1Uses Open Graph / ActivityPub previewPNG/JPG under 1 MB safest

Official page to re-check:https://ogp.me/

How Mastodon crops your image

Link cards are landscape in most themes. Edge text can disappear on narrow columns. Keep titles inside the safe area.

Portrait og:image files get cropped. Prefer 1.91:1 for shared URLs.

Instances cache previews. Changing the image path helps force a fresh card after redesigns.

Three common Mastodon mistakes

  • Relative og:image

    Use absolute https. Relative paths fail for remote fetchers.

  • Blocking bots on the image host

    If anonymous GET fails, the card has text and no picture.

  • Assuming every instance behaves identically

    Themes and cache policies differ. Fix the public tags first, then retest on your home instance.

What to put in the tags

Set og:image, og:title and og:description on the public page. Host a stable PNG or JPG under about a megabyte.

Validate with the [link preview checker](/link-preview-checker/) before you post the URL.

Create a Mastodon-friendly OG image

Opens the generator with the Mastodon size preset selected. Image export stays in your browser.

Related pages

Frequently asked questions

Short answers about Mastodon preview images.

What size should a Mastodon link card image be?

Start with 1200×630 pixels (about 1.91:1). Treat this as a recommended Open Graph default until an official Mastodon size is confirmed.

Why is my Mastodon preview missing the image?

Usually a missing or relative og:image, a blocked fetch, or instance cache. Fix the public tags, then post again.

Does Mastodon need twitter:card?

Prefer Open Graph. Twitter tags alone are not a reliable Mastodon contract.

Can I reuse my Facebook OG image?

Yes. One landscape OG file usually works across Facebook, Slack and Mastodon. Change the path when you redesign.