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Recommended Media Attachment Format

The first three example are our recommendation on how to format image, video, and audio media attachments. Further properties are possible, and might make it into this recommendation at one point. Examples:

  • Focal point and blurhash, see Mastodon
  • fps (frames per second) for videos

The final example cannot be recommended yet as it is not widely supported. However, it illustrates how one can provide multiple versions of the media attachments. A high quality and low quality video in this case. The low quality video is enough for most use cases, and is 40 times smaller.

The recommended format is documented in FEP-1311: Media Attachments.

Examples

Example 1

activity
{
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    {
      "Hashtag": "as:Hashtag",
      "sensitive": "as:sensitive"
    }
  ],
  "type": "Create",
  "actor": "http://pasture-one-actor/actor",
  "to": [
    "https://www.w3.org/ns/activitystreams#Public",
    "http://hollo/@john"
  ],
  "id": "http://pasture-one-actor/actor/3l-ekxiFnAo",
  "published": "2025-07-31T10:30:43Z",
  "object": {
    "type": "Note",
    "attributedTo": "http://pasture-one-actor/actor",
    "to": [
      "https://www.w3.org/ns/activitystreams#Public",
      "http://hollo/@john"
    ],
    "id": "http://pasture-one-actor/actor/o0v9sashnlc",
    "published": "2025-07-31T10:30:43Z",
    "@context": [
      "https://www.w3.org/ns/activitystreams",
      "https://www.w3.org/ns/credentials/v2",
      {
        "size": "https://joinpeertube.org/ns#size"
      }
    ],
    "content": "Recommended Image Format",
    "attachment": [
      {
        "type": "Image",
        "name": "A beautiful cow",
        "url": "http://pasture-one-actor/assets/cow.jpg",
        "width": 100,
        "height": 162,
        "mediaType": "image/jpeg",
        "digestMultibase": "zQmaeDPzhNL32WQZnnzB1H6QJWvvFNEHdViDB71yrxyXU1t",
        "size": 9045
      }
    ],
    "tag": [
      {
        "type": "Mention",
        "href": "http://gotosocial/users/cookie"
      }
    ]
  }
}
hollo
{
  "id": "01986008-c038-7359-a42c-3967dc8efcf7",
  "created_at": "2025-07-31T10:30:43.000Z",
  "in_reply_to_id": null,
  "sensitive": false,
  "spoiler_text": "",
  "visibility": "public",
  "language": null,
  "uri": "http://pasture-one-actor/actor/o0v9sashnlc",
  "url": "http://pasture-one-actor/actor/o0v9sashnlc",
  "replies_count": 0,
  "reblogs_count": 0,
  "favourites_count": 0,
  "favourited": false,
  "reblogged": false,
  "muted": false,
  "bookmarked": false,
  "pinned": false,
  "content": "Recommended Image Format",
  "reblog": null,
  "quote_id": null,
  "quote": null,
  "application": null,
  "account": {
    "id": "01986008-5148-7bfd-94e7-fc5c6ac5a3ed",
    "username": "actor",
    "acct": "actor@pasture-one-actor",
    "display_name": "Test Actor",
    "locked": false,
    "bot": false,
    "created_at": "2025-07-31T10:30:14.535Z",
    "note": "",
    "url": "http://pasture-one-actor/actor",
    "avatar": "http://hollo/image/avatars/original/missing.png",
    "avatar_static": "http://hollo/image/avatars/original/missing.png",
    "header": "http://hollo/image/headers/original/missing.png",
    "header_static": "http://hollo/image/headers/original/missing.png",
    "followers_count": 0,
    "following_count": 0,
    "statuses_count": 0,
    "moved": null,
    "last_status_at": null,
    "emojis": [],
    "fields": []
  },
  "media_attachments": [
    {
      "id": "01986008-c55d-77e8-9200-92fcf2993aba",
      "type": "image",
      "url": "http://pasture-one-actor/assets/cow.jpg",
      "preview_url": "http://pasture-one-actor/assets/cow.jpg",
      "remote_url": null,
      "text_url": null,
      "meta": {
        "original": {
          "width": 100,
          "height": 162,
          "size": "100x162",
          "aspect": 0.6172839506172839
        },
        "small": {
          "width": 100,
          "height": 162,
          "size": "100x162",
          "aspect": 0.6172839506172839
        },
        "focus": {
          "x": 0,
          "y": 0
        }
      },
      "description": null,
      "blurhash": null
    }
  ],
  "mentions": [],
  "tags": [],
  "card": null,
  "emojis": [],
  "emoji_reactions": [],
  "poll": null,
  "filtered": null
}

Example 2

activity
{
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    {
      "Hashtag": "as:Hashtag",
      "sensitive": "as:sensitive"
    }
  ],
  "type": "Create",
  "actor": "http://pasture-one-actor/actor",
  "to": [
    "https://www.w3.org/ns/activitystreams#Public",
    "http://hollo/@john"
  ],
  "id": "http://pasture-one-actor/actor/mMKVC7yukjU",
  "published": "2025-07-31T10:30:44Z",
  "object": {
    "type": "Note",
    "attributedTo": "http://pasture-one-actor/actor",
    "to": [
      "https://www.w3.org/ns/activitystreams#Public",
      "http://hollo/@john"
    ],
    "id": "http://pasture-one-actor/actor/wLMzzEOBth0",
    "published": "2025-07-31T10:30:44Z",
    "@context": [
      "https://www.w3.org/ns/activitystreams",
      "https://www.w3.org/ns/credentials/v2",
      {
        "size": "https://joinpeertube.org/ns#size"
      }
    ],
    "content": "Recommended Video Attachment",
    "attachment": [
      {
        "type": "Video",
        "url": "http://pasture-one-actor/assets/cow_eating.mp4",
        "name": "A beautiful cow eating",
        "width": 256,
        "height": 144,
        "mediaType": "video/mp4",
        "digestMultibase": "zQmSzK5qEe5tpjwGMhmjx9RvVoPkWhEmCwxP2s7wPMpKMoK",
        "size": 54373,
        "duration": "PT3S"
      }
    ],
    "tag": [
      {
        "type": "Mention",
        "href": "http://gotosocial/users/cookie"
      }
    ]
  }
}
hollo
{
  "id": "01986008-c420-79f2-9bd1-8579ae55b97a",
  "created_at": "2025-07-31T10:30:44.000Z",
  "in_reply_to_id": null,
  "sensitive": false,
  "spoiler_text": "",
  "visibility": "public",
  "language": null,
  "uri": "http://pasture-one-actor/actor/wLMzzEOBth0",
  "url": "http://pasture-one-actor/actor/wLMzzEOBth0",
  "replies_count": 0,
  "reblogs_count": 0,
  "favourites_count": 0,
  "favourited": false,
  "reblogged": false,
  "muted": false,
  "bookmarked": false,
  "pinned": false,
  "content": "Recommended Video Attachment",
  "reblog": null,
  "quote_id": null,
  "quote": null,
  "application": null,
  "account": {
    "id": "01986008-5148-7bfd-94e7-fc5c6ac5a3ed",
    "username": "actor",
    "acct": "actor@pasture-one-actor",
    "display_name": "Test Actor",
    "locked": false,
    "bot": false,
    "created_at": "2025-07-31T10:30:14.535Z",
    "note": "",
    "url": "http://pasture-one-actor/actor",
    "avatar": "http://hollo/image/avatars/original/missing.png",
    "avatar_static": "http://hollo/image/avatars/original/missing.png",
    "header": "http://hollo/image/headers/original/missing.png",
    "header_static": "http://hollo/image/headers/original/missing.png",
    "followers_count": 0,
    "following_count": 0,
    "statuses_count": 0,
    "moved": null,
    "last_status_at": null,
    "emojis": [],
    "fields": []
  },
  "media_attachments": [
    {
      "id": "01986008-c868-7de6-9204-092f6944d1f9",
      "type": "video",
      "url": "http://pasture-one-actor/assets/cow_eating.mp4",
      "preview_url": "http://pasture-one-actor/assets/cow_eating.mp4",
      "remote_url": null,
      "text_url": null,
      "meta": {
        "original": {
          "width": 256,
          "height": 144,
          "size": "256x144",
          "aspect": 1.7777777777777777
        },
        "small": {
          "width": 256,
          "height": 144,
          "size": "256x144",
          "aspect": 1.7777777777777777
        },
        "focus": {
          "x": 0,
          "y": 0
        }
      },
      "description": null,
      "blurhash": null
    }
  ],
  "mentions": [],
  "tags": [],
  "card": null,
  "emojis": [],
  "emoji_reactions": [],
  "poll": null,
  "filtered": null
}

Example 3

activity
{
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    {
      "Hashtag": "as:Hashtag",
      "sensitive": "as:sensitive"
    }
  ],
  "type": "Create",
  "actor": "http://pasture-one-actor/actor",
  "to": [
    "https://www.w3.org/ns/activitystreams#Public",
    "http://hollo/@john"
  ],
  "id": "http://pasture-one-actor/actor/XfRBf_KrLuE",
  "published": "2025-07-31T10:30:45Z",
  "object": {
    "type": "Note",
    "attributedTo": "http://pasture-one-actor/actor",
    "to": [
      "https://www.w3.org/ns/activitystreams#Public",
      "http://hollo/@john"
    ],
    "id": "http://pasture-one-actor/actor/faTq6cS9LnM",
    "published": "2025-07-31T10:30:45Z",
    "@context": [
      "https://www.w3.org/ns/activitystreams",
      "https://www.w3.org/ns/credentials/v2",
      {
        "size": "https://joinpeertube.org/ns#size"
      }
    ],
    "content": "Recommended Audio Format",
    "attachment": [
      {
        "type": "Audio",
        "url": "http://pasture-one-actor/assets/cow_moo.mp3",
        "name": "A cow mooing",
        "mediaType": "audio/mpeg",
        "digestMultibase": "zQmSXTyLCPqoiGoUUwKRMKgFdddaAUkvQNr29nhB6tahb9Z",
        "size": 67709,
        "duration": "PT2.1S"
      }
    ],
    "tag": [
      {
        "type": "Mention",
        "href": "http://gotosocial/users/cookie"
      }
    ]
  }
}
hollo
{
  "id": "01986008-c808-70cb-98a4-62f1dc223d80",
  "created_at": "2025-07-31T10:30:45.000Z",
  "in_reply_to_id": null,
  "sensitive": false,
  "spoiler_text": "",
  "visibility": "public",
  "language": null,
  "uri": "http://pasture-one-actor/actor/faTq6cS9LnM",
  "url": "http://pasture-one-actor/actor/faTq6cS9LnM",
  "replies_count": 0,
  "reblogs_count": 0,
  "favourites_count": 0,
  "favourited": false,
  "reblogged": false,
  "muted": false,
  "bookmarked": false,
  "pinned": false,
  "content": "Recommended Audio Format",
  "reblog": null,
  "quote_id": null,
  "quote": null,
  "application": null,
  "account": {
    "id": "01986008-5148-7bfd-94e7-fc5c6ac5a3ed",
    "username": "actor",
    "acct": "actor@pasture-one-actor",
    "display_name": "Test Actor",
    "locked": false,
    "bot": false,
    "created_at": "2025-07-31T10:30:14.535Z",
    "note": "",
    "url": "http://pasture-one-actor/actor",
    "avatar": "http://hollo/image/avatars/original/missing.png",
    "avatar_static": "http://hollo/image/avatars/original/missing.png",
    "header": "http://hollo/image/headers/original/missing.png",
    "header_static": "http://hollo/image/headers/original/missing.png",
    "followers_count": 0,
    "following_count": 0,
    "statuses_count": 0,
    "moved": null,
    "last_status_at": null,
    "emojis": [],
    "fields": []
  },
  "media_attachments": [
    {
      "id": "01986008-cb81-7934-a00b-5ae94c4bb318",
      "type": "audio",
      "url": "http://pasture-one-actor/assets/cow_moo.mp3",
      "preview_url": "http://pasture-one-actor/assets/cow_moo.mp3",
      "remote_url": null,
      "text_url": null,
      "meta": {
        "original": {
          "width": 512,
          "height": 512,
          "size": "512x512",
          "aspect": 1
        },
        "small": {
          "width": 512,
          "height": 512,
          "size": "512x512",
          "aspect": 1
        },
        "focus": {
          "x": 0,
          "y": 0
        }
      },
      "description": null,
      "blurhash": null
    }
  ],
  "mentions": [],
  "tags": [],
  "card": null,
  "emojis": [],
  "emoji_reactions": [],
  "poll": null,
  "filtered": null
}

Example 4

activity
{
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    {
      "Hashtag": "as:Hashtag",
      "sensitive": "as:sensitive"
    }
  ],
  "type": "Create",
  "actor": "http://pasture-one-actor/actor",
  "to": [
    "https://www.w3.org/ns/activitystreams#Public",
    "http://hollo/@john"
  ],
  "id": "http://pasture-one-actor/actor/YwsMnwewrpQ",
  "published": "2025-07-31T10:30:46Z",
  "object": {
    "type": "Note",
    "attributedTo": "http://pasture-one-actor/actor",
    "to": [
      "https://www.w3.org/ns/activitystreams#Public",
      "http://hollo/@john"
    ],
    "id": "http://pasture-one-actor/actor/Onv5jpuKoVg",
    "published": "2025-07-31T10:30:46Z",
    "@context": [
      "https://www.w3.org/ns/activitystreams",
      "https://www.w3.org/ns/credentials/v2",
      {
        "size": "https://joinpeertube.org/ns#size"
      }
    ],
    "content": "Multiple formats for video",
    "attachment": [
      {
        "type": "Video",
        "name": "A beautiful cow eating",
        "url": [
          {
            "type": "Link",
            "size": 54373,
            "digest": "zQmSzK5qEe5tpjwGMhmjx9RvVoPkWhEmCwxP2s7wPMpKMoK",
            "width": 256,
            "height": 144,
            "href": "http://pasture-one-actor/assets/cow_eating.mp4",
            "mediaType": "video/mp4"
          },
          {
            "type": "Link",
            "size": 2271723,
            "digest": "zQme2X4rgWuRdmAtGGMSEbdoeRQ2NAL2VptcdRGTYDZbSKG",
            "width": 1920,
            "height": 1080,
            "href": "http://pasture-one-actor/assets/cow_eating_hd.mp4",
            "mediaType": "video/mp4"
          }
        ],
        "duration": "PT3S"
      }
    ],
    "tag": [
      {
        "type": "Mention",
        "href": "http://gotosocial/users/cookie"
      }
    ]
  }
}
hollo
{
  "id": "01986008-cbf0-74b7-98fc-e1604d1e1272",
  "created_at": "2025-07-31T10:30:46.000Z",
  "in_reply_to_id": null,
  "sensitive": false,
  "spoiler_text": "",
  "visibility": "public",
  "language": null,
  "uri": "http://pasture-one-actor/actor/Onv5jpuKoVg",
  "url": "http://pasture-one-actor/actor/Onv5jpuKoVg",
  "replies_count": 0,
  "reblogs_count": 0,
  "favourites_count": 0,
  "favourited": false,
  "reblogged": false,
  "muted": false,
  "bookmarked": false,
  "pinned": false,
  "content": "Multiple formats for video",
  "reblog": null,
  "quote_id": null,
  "quote": null,
  "application": null,
  "account": {
    "id": "01986008-5148-7bfd-94e7-fc5c6ac5a3ed",
    "username": "actor",
    "acct": "actor@pasture-one-actor",
    "display_name": "Test Actor",
    "locked": false,
    "bot": false,
    "created_at": "2025-07-31T10:30:14.535Z",
    "note": "",
    "url": "http://pasture-one-actor/actor",
    "avatar": "http://hollo/image/avatars/original/missing.png",
    "avatar_static": "http://hollo/image/avatars/original/missing.png",
    "header": "http://hollo/image/headers/original/missing.png",
    "header_static": "http://hollo/image/headers/original/missing.png",
    "followers_count": 0,
    "following_count": 0,
    "statuses_count": 0,
    "moved": null,
    "last_status_at": null,
    "emojis": [],
    "fields": []
  },
  "media_attachments": [
    {
      "id": "01986008-ce80-7a65-a4ec-46eba2ece499",
      "type": "video",
      "url": "http://pasture-one-actor/assets/cow_eating.mp4",
      "preview_url": "http://pasture-one-actor/assets/cow_eating.mp4",
      "remote_url": null,
      "text_url": null,
      "meta": {
        "original": {
          "width": 512,
          "height": 512,
          "size": "512x512",
          "aspect": 1
        },
        "small": {
          "width": 512,
          "height": 512,
          "size": "512x512",
          "aspect": 1
        },
        "focus": {
          "x": 0,
          "y": 0
        }
      },
      "description": null,
      "blurhash": null
    }
  ],
  "mentions": [],
  "tags": [],
  "card": null,
  "emojis": [],
  "emoji_reactions": [],
  "poll": null,
  "filtered": null
}