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": [
"http://gotosocial/users/cookie",
"https://www.w3.org/ns/activitystreams#Public"
],
"id": "http://pasture-one-actor/actor/6w9ujbCw9JI",
"published": "2025-03-23T08:27:25Z",
"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/jT5_B1WNzbU",
"published": "2025-03-23T08:27:25Z",
"content": "no description",
"attachment": {
"type": "Document",
"url": "http://pasture-one-actor/images/100.png"
},
"tag": [
{
"type": "Mention",
"href": "http://gotosocial/users/cookie"
}
]
}
}
gotosocial
{
"id": "01JQ11T9E8Z97MC9ES0MKBM7E4",
"created_at": "2025-03-23T08:27:25.000Z",
"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/jT5_B1WNzbU",
"url": "http://pasture-one-actor/actor/jT5_B1WNzbU",
"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": "01JQ11QM5JKM0XPQD9F110ZSBH",
"username": "actor",
"acct": "actor@pasture-one-actor",
"display_name": "Test Actor",
"locked": true,
"discoverable": false,
"bot": false,
"created_at": "2025-03-23T08:25:57.692Z",
"note": "",
"url": "http://pasture-one-actor/actor",
"avatar": "http://gotosocial/assets/default_avatars/GoToSocial_icon3.png",
"avatar_static": "http://gotosocial/assets/default_avatars/GoToSocial_icon3.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": "2025-03-23T08:27:25.000Z",
"emojis": [],
"fields": []
},
"media_attachments": [
{
"id": "01JQ11T9P8P3HFNJYJMT512GMZ",
"type": "image",
"url": "http://gotosocial/fileserver/01JQ11QM5JKM0XPQD9F110ZSBH/attachment/original/01JQ11T9P8P3HFNJYJMT512GMZ.png",
"text_url": "http://gotosocial/fileserver/01JQ11QM5JKM0XPQD9F110ZSBH/attachment/original/01JQ11T9P8P3HFNJYJMT512GMZ.png",
"preview_url": "http://gotosocial/fileserver/01JQ11QM5JKM0XPQD9F110ZSBH/attachment/small/01JQ11T9P8P3HFNJYJMT512GMZ.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": "L736nElzfQlzlzf%fQf%fQfQfQfQ"
}
],
"mentions": [
{
"id": "01AJKH2GQGHF8XDARSGR3GZS89",
"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": [
"http://gotosocial/users/cookie",
"https://www.w3.org/ns/activitystreams#Public"
],
"id": "http://pasture-one-actor/actor/Ygdpv0yq4xc",
"published": "2025-03-23T08:27:25Z",
"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/267EvhjA1Sk",
"published": "2025-03-23T08:27:25Z",
"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": "01JQ11T9E84QQ7TXASE22C5ET6",
"created_at": "2025-03-23T08:27:25.000Z",
"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/267EvhjA1Sk",
"url": "http://pasture-one-actor/actor/267EvhjA1Sk",
"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": "01JQ11QM5JKM0XPQD9F110ZSBH",
"username": "actor",
"acct": "actor@pasture-one-actor",
"display_name": "Test Actor",
"locked": true,
"discoverable": false,
"bot": false,
"created_at": "2025-03-23T08:25:57.692Z",
"note": "",
"url": "http://pasture-one-actor/actor",
"avatar": "http://gotosocial/assets/default_avatars/GoToSocial_icon3.png",
"avatar_static": "http://gotosocial/assets/default_avatars/GoToSocial_icon3.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": "2025-03-23T08:27:25.000Z",
"emojis": [],
"fields": []
},
"media_attachments": [
{
"id": "01JQ11TABZNN7FDCXNZ1AVGPVP",
"type": "image",
"url": "http://gotosocial/fileserver/01JQ11QM5JKM0XPQD9F110ZSBH/attachment/original/01JQ11TABZNN7FDCXNZ1AVGPVP.png",
"text_url": "http://gotosocial/fileserver/01JQ11QM5JKM0XPQD9F110ZSBH/attachment/original/01JQ11TABZNN7FDCXNZ1AVGPVP.png",
"preview_url": "http://gotosocial/fileserver/01JQ11QM5JKM0XPQD9F110ZSBH/attachment/small/01JQ11TABZNN7FDCXNZ1AVGPVP.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": "L6EF:i*BfQ*B*BkAfQkAfQfQfQfQ"
}
],
"mentions": [
{
"id": "01AJKH2GQGHF8XDARSGR3GZS89",
"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": [
"http://gotosocial/users/cookie",
"https://www.w3.org/ns/activitystreams#Public"
],
"id": "http://pasture-one-actor/actor/gs0dazjb5g8",
"published": "2025-03-23T08:27:26Z",
"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/0anxwAwSgl0",
"published": "2025-03-23T08:27:26Z",
"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": "01JQ11TADG48TV2AJ935505YRR",
"created_at": "2025-03-23T08:27:26.000Z",
"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/0anxwAwSgl0",
"url": "http://pasture-one-actor/actor/0anxwAwSgl0",
"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": "01JQ11QM5JKM0XPQD9F110ZSBH",
"username": "actor",
"acct": "actor@pasture-one-actor",
"display_name": "Test Actor",
"locked": true,
"discoverable": false,
"bot": false,
"created_at": "2025-03-23T08:25:57.692Z",
"note": "",
"url": "http://pasture-one-actor/actor",
"avatar": "http://gotosocial/assets/default_avatars/GoToSocial_icon3.png",
"avatar_static": "http://gotosocial/assets/default_avatars/GoToSocial_icon3.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": "2025-03-23T08:27:26.000Z",
"emojis": [],
"fields": []
},
"media_attachments": [
{
"id": "01JQ11TB1E095STNE66C0SS6XN",
"type": "image",
"url": "http://gotosocial/fileserver/01JQ11QM5JKM0XPQD9F110ZSBH/attachment/original/01JQ11TB1E095STNE66C0SS6XN.png",
"text_url": "http://gotosocial/fileserver/01JQ11QM5JKM0XPQD9F110ZSBH/attachment/original/01JQ11TB1E095STNE66C0SS6XN.png",
"preview_url": "http://gotosocial/fileserver/01JQ11QM5JKM0XPQD9F110ZSBH/attachment/small/01JQ11TB1E095STNE66C0SS6XN.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": "01AJKH2GQGHF8XDARSGR3GZS89",
"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": [
"http://gotosocial/users/cookie",
"https://www.w3.org/ns/activitystreams#Public"
],
"id": "http://pasture-one-actor/actor/ybU_pFwyEqk",
"published": "2025-03-23T08:27:27Z",
"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/YizuAyfxM4M",
"published": "2025-03-23T08:27:27Z",
"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": "01JQ11TBCR88ZV90QPPXKKT5JX",
"created_at": "2025-03-23T08:27:27.000Z",
"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/YizuAyfxM4M",
"url": "http://pasture-one-actor/actor/YizuAyfxM4M",
"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": "01JQ11QM5JKM0XPQD9F110ZSBH",
"username": "actor",
"acct": "actor@pasture-one-actor",
"display_name": "Test Actor",
"locked": true,
"discoverable": false,
"bot": false,
"created_at": "2025-03-23T08:25:57.692Z",
"note": "",
"url": "http://pasture-one-actor/actor",
"avatar": "http://gotosocial/assets/default_avatars/GoToSocial_icon3.png",
"avatar_static": "http://gotosocial/assets/default_avatars/GoToSocial_icon3.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": "2025-03-23T08:27:27.000Z",
"emojis": [],
"fields": []
},
"media_attachments": [
{
"id": "01JQ11TBPA5C39GHBBZPP46ZYX",
"type": "image",
"url": "http://gotosocial/fileserver/01JQ11QM5JKM0XPQD9F110ZSBH/attachment/original/01JQ11TBPA5C39GHBBZPP46ZYX.png",
"text_url": "http://gotosocial/fileserver/01JQ11QM5JKM0XPQD9F110ZSBH/attachment/original/01JQ11TBPA5C39GHBBZPP46ZYX.png",
"preview_url": "http://gotosocial/fileserver/01JQ11QM5JKM0XPQD9F110ZSBH/attachment/small/01JQ11TBPA5C39GHBBZPP46ZYX.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": "01AJKH2GQGHF8XDARSGR3GZS89",
"username": "cookie",
"url": "http://gotosocial/@cookie",
"acct": "cookie"
}
],
"tags": [],
"emojis": [],
"card": null,
"poll": null
}