Image Description¶
The Image type is defined in ActivityStreams Vocabulary.
In this support table, we only consider how the image description, commonly called AltText is handled. Image descriptions are important from an accessibility standpoint, see WCAG 2.2. Text Alternatives.
It seems that certain implementations, e.g. misskey, store the image description on a per image URL basis and not for every instance of an image reference.
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://gotosocial/users/cookie"
],
"id": "http://pasture-one-actor/activity/KX6N5v0rDPg",
"published": "2025-10-23T10:56:17Z",
"object": {
"type": "Note",
"attributedTo": "http://pasture-one-actor/actor",
"to": [
"https://www.w3.org/ns/activitystreams#Public",
"http://gotosocial/users/cookie"
],
"id": "http://pasture-one-actor/object/NjntHKdZjLI",
"published": "2025-10-23T10:56:17Z",
"content": "no description",
"attachment": {
"type": "Image",
"url": "http://pasture-one-actor/images/4400b13b-d597-484c-bbf2-f09c01564334.png"
},
"tag": [
{
"type": "Mention",
"href": "http://gotosocial/users/cookie"
}
]
}
}
gotosocial
{
"id": "01K88BCP386AY03DECQKCWG30X",
"created_at": "2025-10-23T10:56:17.000Z",
"in_reply_to_id": null,
"in_reply_to_account_id": null,
"sensitive": false,
"spoiler_text": "",
"visibility": "public",
"language": null,
"uri": "http://pasture-one-actor/object/NjntHKdZjLI",
"url": "http://pasture-one-actor/object/NjntHKdZjLI",
"replies_count": 0,
"reblogs_count": 0,
"favourites_count": 0,
"favourited": false,
"reblogged": false,
"muted": false,
"bookmarked": false,
"pinned": false,
"content": "no description",
"reblog": null,
"account": {
"id": "01K88B9DBED70DZXVFZRY6BE5H",
"username": "actor",
"acct": "actor@pasture-one-actor",
"display_name": "Test Actor",
"locked": true,
"discoverable": false,
"bot": false,
"created_at": "2025-10-23T10:54:29.756Z",
"note": "",
"url": "http://pasture-one-actor/actor",
"avatar": "http://gotosocial/assets/default_avatars/GoToSocial_icon6.png",
"avatar_static": "http://gotosocial/assets/default_avatars/GoToSocial_icon6.png",
"header": "http://gotosocial/assets/default_header.png",
"header_static": "http://gotosocial/assets/default_header.png",
"followers_count": 0,
"following_count": 0,
"statuses_count": 75,
"last_status_at": "2025-10-23T10:56:17.000Z",
"emojis": [],
"fields": []
},
"media_attachments": [
{
"id": "01K88BCP7V5C47XZJXWAAT2SMB",
"type": "image",
"url": "http://gotosocial/fileserver/01K88B9DBED70DZXVFZRY6BE5H/attachment/original/01K88BCP7V5C47XZJXWAAT2SMB.png",
"text_url": "http://gotosocial/fileserver/01K88B9DBED70DZXVFZRY6BE5H/attachment/original/01K88BCP7V5C47XZJXWAAT2SMB.png",
"preview_url": "http://gotosocial/fileserver/01K88B9DBED70DZXVFZRY6BE5H/attachment/small/01K88BCP7V5C47XZJXWAAT2SMB.jpg",
"remote_url": "http://pasture-one-actor/images/4400b13b-d597-484c-bbf2-f09c01564334.png",
"preview_remote_url": null,
"meta": {
"original": {
"width": 40,
"height": 40,
"size": "40x40",
"aspect": 1
},
"small": {
"width": 40,
"height": 40,
"size": "40x40",
"aspect": 1
},
"focus": {
"x": 0,
"y": 0
}
},
"description": null,
"blurhash": "L3E56e.gfQ.g.gkBfQkBfQfQfQfQ"
}
],
"mentions": [
{
"id": "01QK870GYNYBKP64P81D09JF7X",
"username": "cookie",
"url": "http://gotosocial/@cookie",
"acct": "cookie"
}
],
"tags": [],
"emojis": [],
"card": null,
"poll": 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://gotosocial/users/cookie"
],
"id": "http://pasture-one-actor/activity/_cbnEhabeqM",
"published": "2025-10-23T10:56:17Z",
"object": {
"type": "Note",
"attributedTo": "http://pasture-one-actor/actor",
"to": [
"https://www.w3.org/ns/activitystreams#Public",
"http://gotosocial/users/cookie"
],
"id": "http://pasture-one-actor/object/ouG877Wyst8",
"published": "2025-10-23T10:56:17Z",
"content": "name, summary and content",
"attachment": {
"type": "Image",
"url": "http://pasture-one-actor/images/7e38ed0a-1c27-4a65-b9c6-b7e442be29db.png",
"name": "name",
"summary": "summary",
"content": "content"
},
"tag": [
{
"type": "Mention",
"href": "http://gotosocial/users/cookie"
}
]
}
}
gotosocial
{
"id": "01K88BCP38Y30E2WH65S463HX4",
"created_at": "2025-10-23T10:56:17.000Z",
"in_reply_to_id": null,
"in_reply_to_account_id": null,
"sensitive": false,
"spoiler_text": "",
"visibility": "public",
"language": null,
"uri": "http://pasture-one-actor/object/ouG877Wyst8",
"url": "http://pasture-one-actor/object/ouG877Wyst8",
"replies_count": 0,
"reblogs_count": 0,
"favourites_count": 0,
"favourited": false,
"reblogged": false,
"muted": false,
"bookmarked": false,
"pinned": false,
"content": "name, summary and content",
"reblog": null,
"account": {
"id": "01K88B9DBED70DZXVFZRY6BE5H",
"username": "actor",
"acct": "actor@pasture-one-actor",
"display_name": "Test Actor",
"locked": true,
"discoverable": false,
"bot": false,
"created_at": "2025-10-23T10:54:29.756Z",
"note": "",
"url": "http://pasture-one-actor/actor",
"avatar": "http://gotosocial/assets/default_avatars/GoToSocial_icon6.png",
"avatar_static": "http://gotosocial/assets/default_avatars/GoToSocial_icon6.png",
"header": "http://gotosocial/assets/default_header.png",
"header_static": "http://gotosocial/assets/default_header.png",
"followers_count": 0,
"following_count": 0,
"statuses_count": 76,
"last_status_at": "2025-10-23T10:56:17.000Z",
"emojis": [],
"fields": []
},
"media_attachments": [
{
"id": "01K88BCPSQYPFX4ZKVKF4TTSX5",
"type": "image",
"url": "http://gotosocial/fileserver/01K88B9DBED70DZXVFZRY6BE5H/attachment/original/01K88BCPSQYPFX4ZKVKF4TTSX5.png",
"text_url": "http://gotosocial/fileserver/01K88B9DBED70DZXVFZRY6BE5H/attachment/original/01K88BCPSQYPFX4ZKVKF4TTSX5.png",
"preview_url": "http://gotosocial/fileserver/01K88B9DBED70DZXVFZRY6BE5H/attachment/small/01K88BCPSQYPFX4ZKVKF4TTSX5.jpg",
"remote_url": "http://pasture-one-actor/images/7e38ed0a-1c27-4a65-b9c6-b7e442be29db.png",
"preview_remote_url": null,
"meta": {
"original": {
"width": 40,
"height": 40,
"size": "40x40",
"aspect": 1
},
"small": {
"width": 40,
"height": 40,
"size": "40x40",
"aspect": 1
},
"focus": {
"x": 0,
"y": 0
}
},
"description": "summary",
"blurhash": "L4Jh*h^BfQ^B^Bj]fQj]fQfQfQfQ"
}
],
"mentions": [
{
"id": "01QK870GYNYBKP64P81D09JF7X",
"username": "cookie",
"url": "http://gotosocial/@cookie",
"acct": "cookie"
}
],
"tags": [],
"emojis": [],
"card": null,
"poll": 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://gotosocial/users/cookie"
],
"id": "http://pasture-one-actor/activity/Anz0ie1oKiM",
"published": "2025-10-23T10:56:18Z",
"object": {
"type": "Note",
"attributedTo": "http://pasture-one-actor/actor",
"to": [
"https://www.w3.org/ns/activitystreams#Public",
"http://gotosocial/users/cookie"
],
"id": "http://pasture-one-actor/object/YGv01_JUCKM",
"published": "2025-10-23T10:56:18Z",
"content": "only name",
"attachment": [
{
"type": "Image",
"url": "http://pasture-one-actor/assets/FediverseLogo.png",
"name": "name",
"imageType": "image/jpeg"
}
],
"tag": [
{
"type": "Mention",
"href": "http://gotosocial/users/cookie"
}
]
}
}
gotosocial
{
"id": "01K88BCQ2GNJMF2WEQYE14KFG4",
"created_at": "2025-10-23T10:56:18.000Z",
"in_reply_to_id": null,
"in_reply_to_account_id": null,
"sensitive": false,
"spoiler_text": "",
"visibility": "public",
"language": null,
"uri": "http://pasture-one-actor/object/YGv01_JUCKM",
"url": "http://pasture-one-actor/object/YGv01_JUCKM",
"replies_count": 0,
"reblogs_count": 0,
"favourites_count": 0,
"favourited": false,
"reblogged": false,
"muted": false,
"bookmarked": false,
"pinned": false,
"content": "only name",
"reblog": null,
"account": {
"id": "01K88B9DBED70DZXVFZRY6BE5H",
"username": "actor",
"acct": "actor@pasture-one-actor",
"display_name": "Test Actor",
"locked": true,
"discoverable": false,
"bot": false,
"created_at": "2025-10-23T10:54:29.756Z",
"note": "",
"url": "http://pasture-one-actor/actor",
"avatar": "http://gotosocial/assets/default_avatars/GoToSocial_icon6.png",
"avatar_static": "http://gotosocial/assets/default_avatars/GoToSocial_icon6.png",
"header": "http://gotosocial/assets/default_header.png",
"header_static": "http://gotosocial/assets/default_header.png",
"followers_count": 0,
"following_count": 0,
"statuses_count": 77,
"last_status_at": "2025-10-23T10:56:18.000Z",
"emojis": [],
"fields": []
},
"media_attachments": [
{
"id": "01K88BCQBEQ5Z4F29GZEXXQS1T",
"type": "image",
"url": "http://gotosocial/fileserver/01K88B9DBED70DZXVFZRY6BE5H/attachment/original/01K88BCQBEQ5Z4F29GZEXXQS1T.png",
"text_url": "http://gotosocial/fileserver/01K88B9DBED70DZXVFZRY6BE5H/attachment/original/01K88BCQBEQ5Z4F29GZEXXQS1T.png",
"preview_url": "http://gotosocial/fileserver/01K88B9DBED70DZXVFZRY6BE5H/attachment/small/01K88BCQBEQ5Z4F29GZEXXQS1T.jpg",
"remote_url": "http://pasture-one-actor/assets/FediverseLogo.png",
"preview_remote_url": null,
"meta": {
"original": {
"width": 1548,
"height": 1548,
"size": "1548x1548",
"aspect": 1
},
"small": {
"width": 512,
"height": 512,
"size": "512x512",
"aspect": 1
},
"focus": {
"x": 0,
"y": 0
}
},
"description": "name",
"blurhash": "LIB{x~.}9Fcn}gnOEUxBDlK[N1wi"
}
],
"mentions": [
{
"id": "01QK870GYNYBKP64P81D09JF7X",
"username": "cookie",
"url": "http://gotosocial/@cookie",
"acct": "cookie"
}
],
"tags": [],
"emojis": [],
"card": null,
"poll": 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://gotosocial/users/cookie"
],
"id": "http://pasture-one-actor/activity/ubLIexmcLA0",
"published": "2025-10-23T10:56:18Z",
"object": {
"type": "Note",
"attributedTo": "http://pasture-one-actor/actor",
"to": [
"https://www.w3.org/ns/activitystreams#Public",
"http://gotosocial/users/cookie"
],
"id": "http://pasture-one-actor/object/sDA-g2vevbQ",
"published": "2025-10-23T10:56:18Z",
"content": "only summary",
"attachment": {
"type": "Image",
"url": "http://pasture-one-actor/images/ae9db963-fd04-41ae-9673-6592cb34f29d.png",
"name": "name",
"summary": "summary",
"content": "content"
},
"tag": [
{
"type": "Mention",
"href": "http://gotosocial/users/cookie"
}
]
}
}
gotosocial
{
"id": "01K88BCQ2G32SN7Y29QB8AT3PE",
"created_at": "2025-10-23T10:56:18.000Z",
"in_reply_to_id": null,
"in_reply_to_account_id": null,
"sensitive": false,
"spoiler_text": "",
"visibility": "public",
"language": null,
"uri": "http://pasture-one-actor/object/sDA-g2vevbQ",
"url": "http://pasture-one-actor/object/sDA-g2vevbQ",
"replies_count": 0,
"reblogs_count": 0,
"favourites_count": 0,
"favourited": false,
"reblogged": false,
"muted": false,
"bookmarked": false,
"pinned": false,
"content": "only summary",
"reblog": null,
"account": {
"id": "01K88B9DBED70DZXVFZRY6BE5H",
"username": "actor",
"acct": "actor@pasture-one-actor",
"display_name": "Test Actor",
"locked": true,
"discoverable": false,
"bot": false,
"created_at": "2025-10-23T10:54:29.756Z",
"note": "",
"url": "http://pasture-one-actor/actor",
"avatar": "http://gotosocial/assets/default_avatars/GoToSocial_icon6.png",
"avatar_static": "http://gotosocial/assets/default_avatars/GoToSocial_icon6.png",
"header": "http://gotosocial/assets/default_header.png",
"header_static": "http://gotosocial/assets/default_header.png",
"followers_count": 0,
"following_count": 0,
"statuses_count": 78,
"last_status_at": "2025-10-23T10:56:18.000Z",
"emojis": [],
"fields": []
},
"media_attachments": [
{
"id": "01K88BCQXDMW03DCBNDVJCR6GD",
"type": "image",
"url": "http://gotosocial/fileserver/01K88B9DBED70DZXVFZRY6BE5H/attachment/original/01K88BCQXDMW03DCBNDVJCR6GD.png",
"text_url": "http://gotosocial/fileserver/01K88B9DBED70DZXVFZRY6BE5H/attachment/original/01K88BCQXDMW03DCBNDVJCR6GD.png",
"preview_url": "http://gotosocial/fileserver/01K88B9DBED70DZXVFZRY6BE5H/attachment/small/01K88BCQXDMW03DCBNDVJCR6GD.jpg",
"remote_url": "http://pasture-one-actor/images/ae9db963-fd04-41ae-9673-6592cb34f29d.png",
"preview_remote_url": null,
"meta": {
"original": {
"width": 40,
"height": 40,
"size": "40x40",
"aspect": 1
},
"small": {
"width": 40,
"height": 40,
"size": "40x40",
"aspect": 1
},
"focus": {
"x": 0,
"y": 0
}
},
"description": "summary",
"blurhash": "L5A5K1y.fQy.y.kBfQkBfQfQfQfQ"
}
],
"mentions": [
{
"id": "01QK870GYNYBKP64P81D09JF7X",
"username": "cookie",
"url": "http://gotosocial/@cookie",
"acct": "cookie"
}
],
"tags": [],
"emojis": [],
"card": null,
"poll": null
}
Example 5¶
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://gotosocial/users/cookie"
],
"id": "http://pasture-one-actor/activity/ZjmwecQgcg4",
"published": "2025-10-23T10:56:19Z",
"object": {
"type": "Note",
"attributedTo": "http://pasture-one-actor/actor",
"to": [
"https://www.w3.org/ns/activitystreams#Public",
"http://gotosocial/users/cookie"
],
"id": "http://pasture-one-actor/object/CgyP4aRi4uI",
"published": "2025-10-23T10:56:19Z",
"content": "only content",
"attachment": {
"type": "Image",
"url": "http://pasture-one-actor/images/ceac6eba-e968-4cf7-8571-947b63811678.png",
"content": "content"
},
"tag": [
{
"type": "Mention",
"href": "http://gotosocial/users/cookie"
}
]
}
}
gotosocial
{
"id": "01K88BCR1RYAXWW4M1Y5JPBVHC",
"created_at": "2025-10-23T10:56:19.000Z",
"in_reply_to_id": null,
"in_reply_to_account_id": null,
"sensitive": false,
"spoiler_text": "",
"visibility": "public",
"language": null,
"uri": "http://pasture-one-actor/object/CgyP4aRi4uI",
"url": "http://pasture-one-actor/object/CgyP4aRi4uI",
"replies_count": 0,
"reblogs_count": 0,
"favourites_count": 0,
"favourited": false,
"reblogged": false,
"muted": false,
"bookmarked": false,
"pinned": false,
"content": "only content",
"reblog": null,
"account": {
"id": "01K88B9DBED70DZXVFZRY6BE5H",
"username": "actor",
"acct": "actor@pasture-one-actor",
"display_name": "Test Actor",
"locked": true,
"discoverable": false,
"bot": false,
"created_at": "2025-10-23T10:54:29.756Z",
"note": "",
"url": "http://pasture-one-actor/actor",
"avatar": "http://gotosocial/assets/default_avatars/GoToSocial_icon6.png",
"avatar_static": "http://gotosocial/assets/default_avatars/GoToSocial_icon6.png",
"header": "http://gotosocial/assets/default_header.png",
"header_static": "http://gotosocial/assets/default_header.png",
"followers_count": 0,
"following_count": 0,
"statuses_count": 79,
"last_status_at": "2025-10-23T10:56:19.000Z",
"emojis": [],
"fields": []
},
"media_attachments": [
{
"id": "01K88BCRF1EAJ9DZCPERFH311H",
"type": "image",
"url": "http://gotosocial/fileserver/01K88B9DBED70DZXVFZRY6BE5H/attachment/original/01K88BCRF1EAJ9DZCPERFH311H.png",
"text_url": "http://gotosocial/fileserver/01K88B9DBED70DZXVFZRY6BE5H/attachment/original/01K88BCRF1EAJ9DZCPERFH311H.png",
"preview_url": "http://gotosocial/fileserver/01K88B9DBED70DZXVFZRY6BE5H/attachment/small/01K88BCRF1EAJ9DZCPERFH311H.jpg",
"remote_url": "http://pasture-one-actor/images/ceac6eba-e968-4cf7-8571-947b63811678.png",
"preview_remote_url": null,
"meta": {
"original": {
"width": 40,
"height": 40,
"size": "40x40",
"aspect": 1
},
"small": {
"width": 40,
"height": 40,
"size": "40x40",
"aspect": 1
},
"focus": {
"x": 0,
"y": 0
}
},
"description": null,
"blurhash": "L9TIZr~nfQ~n~noefQoefQfQfQfQ"
}
],
"mentions": [
{
"id": "01QK870GYNYBKP64P81D09JF7X",
"username": "cookie",
"url": "http://gotosocial/@cookie",
"acct": "cookie"
}
],
"tags": [],
"emojis": [],
"card": null,
"poll": null
}
Example 6¶
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://gotosocial/users/cookie"
],
"id": "http://pasture-one-actor/activity/AjlxUuHnYh0",
"published": "2025-10-23T10:56:19Z",
"object": {
"type": "Note",
"attributedTo": "http://pasture-one-actor/actor",
"to": [
"https://www.w3.org/ns/activitystreams#Public",
"http://gotosocial/users/cookie"
],
"id": "http://pasture-one-actor/object/MAgqfWkOaic",
"published": "2025-10-23T10:56:19Z",
"content": "no comment in attachment; reused image",
"attachment": [
{
"type": "Image",
"url": "http://pasture-one-actor/assets/FediverseLogo.png"
}
],
"tag": [
{
"type": "Mention",
"href": "http://gotosocial/users/cookie"
}
]
}
}
gotosocial
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