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. firefish, 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/actor/-fUZI3LIi2Q",
"published": "2025-07-31T10:22:44Z",
"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/actor/T0dPAhOuorU",
"published": "2025-07-31T10:22:44Z",
"content": "no description",
"attachment": {
"type": "Document",
"url": "http://pasture-one-actor/images/100.png"
},
"tag": [
{
"type": "Mention",
"href": "http://gotosocial/users/cookie"
}
]
}
}
gotosocial
{
"id": "01K1G02W90QMR9DBZ9WD7JXF6P",
"created_at": "2025-07-31T10:22:44.000Z",
"in_reply_to_id": null,
"in_reply_to_account_id": null,
"sensitive": false,
"spoiler_text": "",
"visibility": "public",
"language": null,
"uri": "http://pasture-one-actor/actor/T0dPAhOuorU",
"url": "http://pasture-one-actor/actor/T0dPAhOuorU",
"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": "01K1G0072548GTA3W6MWNX04WC",
"username": "actor",
"acct": "actor@pasture-one-actor",
"display_name": "Test Actor",
"locked": true,
"discoverable": false,
"bot": false,
"created_at": "2025-07-31T10:21:16.752Z",
"note": "",
"url": "http://pasture-one-actor/actor",
"avatar": "http://gotosocial/assets/default_avatars/GoToSocial_icon2.png",
"avatar_static": "http://gotosocial/assets/default_avatars/GoToSocial_icon2.png",
"header": "http://gotosocial/assets/default_header.png",
"header_static": "http://gotosocial/assets/default_header.png",
"followers_count": 0,
"following_count": 0,
"statuses_count": 35,
"last_status_at": "2025-07-31T10:22:44.000Z",
"emojis": [],
"fields": []
},
"media_attachments": [
{
"id": "01K1G02WGFYDDZ4993ZTMSV3EN",
"type": "image",
"url": "http://gotosocial/fileserver/01K1G0072548GTA3W6MWNX04WC/attachment/original/01K1G02WGFYDDZ4993ZTMSV3EN.png",
"text_url": "http://gotosocial/fileserver/01K1G0072548GTA3W6MWNX04WC/attachment/original/01K1G02WGFYDDZ4993ZTMSV3EN.png",
"preview_url": "http://gotosocial/fileserver/01K1G0072548GTA3W6MWNX04WC/attachment/small/01K1G02WGFYDDZ4993ZTMSV3EN.jpg",
"remote_url": "http://pasture-one-actor/images/100.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": "L49Bjay=fQy=y=kBfQkBfQfQfQfQ"
}
],
"mentions": [
{
"id": "01JSD9ARR6H9BBGHBNY98RD023",
"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/actor/v0IwhZnqcbM",
"published": "2025-07-31T10:22:44Z",
"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/actor/knaESyBM_yc",
"published": "2025-07-31T10:22:44Z",
"content": "text",
"attachment": {
"type": "Document",
"url": "http://pasture-one-actor/images/100.png",
"name": "name",
"summary": "summary",
"content": "content"
},
"tag": [
{
"type": "Mention",
"href": "http://gotosocial/users/cookie"
}
]
}
}
gotosocial
{
"id": "01K1G02W90T6FB31QS320D5DNH",
"created_at": "2025-07-31T10:22:44.000Z",
"in_reply_to_id": null,
"in_reply_to_account_id": null,
"sensitive": false,
"spoiler_text": "",
"visibility": "public",
"language": null,
"uri": "http://pasture-one-actor/actor/knaESyBM_yc",
"url": "http://pasture-one-actor/actor/knaESyBM_yc",
"replies_count": 0,
"reblogs_count": 0,
"favourites_count": 0,
"favourited": false,
"reblogged": false,
"muted": false,
"bookmarked": false,
"pinned": false,
"content": "text",
"reblog": null,
"account": {
"id": "01K1G0072548GTA3W6MWNX04WC",
"username": "actor",
"acct": "actor@pasture-one-actor",
"display_name": "Test Actor",
"locked": true,
"discoverable": false,
"bot": false,
"created_at": "2025-07-31T10:21:16.752Z",
"note": "",
"url": "http://pasture-one-actor/actor",
"avatar": "http://gotosocial/assets/default_avatars/GoToSocial_icon2.png",
"avatar_static": "http://gotosocial/assets/default_avatars/GoToSocial_icon2.png",
"header": "http://gotosocial/assets/default_header.png",
"header_static": "http://gotosocial/assets/default_header.png",
"followers_count": 0,
"following_count": 0,
"statuses_count": 36,
"last_status_at": "2025-07-31T10:22:44.000Z",
"emojis": [],
"fields": []
},
"media_attachments": [
{
"id": "01K1G02X62K35K6N66M6MP4TQA",
"type": "image",
"url": "http://gotosocial/fileserver/01K1G0072548GTA3W6MWNX04WC/attachment/original/01K1G02X62K35K6N66M6MP4TQA.png",
"text_url": "http://gotosocial/fileserver/01K1G0072548GTA3W6MWNX04WC/attachment/original/01K1G02X62K35K6N66M6MP4TQA.png",
"preview_url": "http://gotosocial/fileserver/01K1G0072548GTA3W6MWNX04WC/attachment/small/01K1G02X62K35K6N66M6MP4TQA.jpg",
"remote_url": "http://pasture-one-actor/images/100.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": "L42.4{l+fQl+l+f*fQf*fQfQfQfQ"
}
],
"mentions": [
{
"id": "01JSD9ARR6H9BBGHBNY98RD023",
"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/actor/O5QKYeCx798",
"published": "2025-07-31T10:22:45Z",
"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/actor/hwd7CVGL_Hw",
"published": "2025-07-31T10:22:45Z",
"content": "text",
"attachment": [
{
"type": "Document",
"url": "http://pasture-one-actor/assets/FediverseLogo.png",
"name": "name",
"imageType": "image/jpeg"
}
],
"tag": [
{
"type": "Mention",
"href": "http://gotosocial/users/cookie"
}
]
}
}
gotosocial
{
"id": "01K1G02X88GEB6R0DKP51T6F2Y",
"created_at": "2025-07-31T10:22:45.000Z",
"in_reply_to_id": null,
"in_reply_to_account_id": null,
"sensitive": false,
"spoiler_text": "",
"visibility": "public",
"language": null,
"uri": "http://pasture-one-actor/actor/hwd7CVGL_Hw",
"url": "http://pasture-one-actor/actor/hwd7CVGL_Hw",
"replies_count": 0,
"reblogs_count": 0,
"favourites_count": 0,
"favourited": false,
"reblogged": false,
"muted": false,
"bookmarked": false,
"pinned": false,
"content": "text",
"reblog": null,
"account": {
"id": "01K1G0072548GTA3W6MWNX04WC",
"username": "actor",
"acct": "actor@pasture-one-actor",
"display_name": "Test Actor",
"locked": true,
"discoverable": false,
"bot": false,
"created_at": "2025-07-31T10:21:16.752Z",
"note": "",
"url": "http://pasture-one-actor/actor",
"avatar": "http://gotosocial/assets/default_avatars/GoToSocial_icon2.png",
"avatar_static": "http://gotosocial/assets/default_avatars/GoToSocial_icon2.png",
"header": "http://gotosocial/assets/default_header.png",
"header_static": "http://gotosocial/assets/default_header.png",
"followers_count": 0,
"following_count": 0,
"statuses_count": 37,
"last_status_at": "2025-07-31T10:22:45.000Z",
"emojis": [],
"fields": []
},
"media_attachments": [
{
"id": "01K1G02XVVJ7R2QGTKQ9ZK3X15",
"type": "image",
"url": "http://gotosocial/fileserver/01K1G0072548GTA3W6MWNX04WC/attachment/original/01K1G02XVVJ7R2QGTKQ9ZK3X15.png",
"text_url": "http://gotosocial/fileserver/01K1G0072548GTA3W6MWNX04WC/attachment/original/01K1G02XVVJ7R2QGTKQ9ZK3X15.png",
"preview_url": "http://gotosocial/fileserver/01K1G0072548GTA3W6MWNX04WC/attachment/small/01K1G02XVVJ7R2QGTKQ9ZK3X15.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": "01JSD9ARR6H9BBGHBNY98RD023",
"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/actor/kuEcfHeteHg",
"published": "2025-07-31T10:22:46Z",
"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/actor/PMtisfJRpqw",
"published": "2025-07-31T10:22:46Z",
"content": "no comment in attachment",
"attachment": [
{
"type": "Document",
"url": "http://pasture-one-actor/assets/FediverseLogo.png"
}
],
"tag": [
{
"type": "Mention",
"href": "http://gotosocial/users/cookie"
}
]
}
}
gotosocial
{
"id": "01K1G02Y7GKQYQ4QFWZXHB5F21",
"created_at": "2025-07-31T10:22:46.000Z",
"in_reply_to_id": null,
"in_reply_to_account_id": null,
"sensitive": false,
"spoiler_text": "",
"visibility": "public",
"language": null,
"uri": "http://pasture-one-actor/actor/PMtisfJRpqw",
"url": "http://pasture-one-actor/actor/PMtisfJRpqw",
"replies_count": 0,
"reblogs_count": 0,
"favourites_count": 0,
"favourited": false,
"reblogged": false,
"muted": false,
"bookmarked": false,
"pinned": false,
"content": "no comment in attachment",
"reblog": null,
"account": {
"id": "01K1G0072548GTA3W6MWNX04WC",
"username": "actor",
"acct": "actor@pasture-one-actor",
"display_name": "Test Actor",
"locked": true,
"discoverable": false,
"bot": false,
"created_at": "2025-07-31T10:21:16.752Z",
"note": "",
"url": "http://pasture-one-actor/actor",
"avatar": "http://gotosocial/assets/default_avatars/GoToSocial_icon2.png",
"avatar_static": "http://gotosocial/assets/default_avatars/GoToSocial_icon2.png",
"header": "http://gotosocial/assets/default_header.png",
"header_static": "http://gotosocial/assets/default_header.png",
"followers_count": 0,
"following_count": 0,
"statuses_count": 38,
"last_status_at": "2025-07-31T10:22:46.000Z",
"emojis": [],
"fields": []
},
"media_attachments": [
{
"id": "01K1G02YG7ZQ4CRFVFQFED77DZ",
"type": "image",
"url": "http://gotosocial/fileserver/01K1G0072548GTA3W6MWNX04WC/attachment/original/01K1G02YG7ZQ4CRFVFQFED77DZ.png",
"text_url": "http://gotosocial/fileserver/01K1G0072548GTA3W6MWNX04WC/attachment/original/01K1G02YG7ZQ4CRFVFQFED77DZ.png",
"preview_url": "http://gotosocial/fileserver/01K1G0072548GTA3W6MWNX04WC/attachment/small/01K1G02YG7ZQ4CRFVFQFED77DZ.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": null,
"blurhash": "LIB{x~.}9Fcn}gnOEUxBDlK[N1wi"
}
],
"mentions": [
{
"id": "01JSD9ARR6H9BBGHBNY98RD023",
"username": "cookie",
"url": "http://gotosocial/@cookie",
"acct": "cookie"
}
],
"tags": [],
"emojis": [],
"card": null,
"poll": null
}