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/activity/z7swf2fLQTY",
"published": "2025-08-30T18:58:23Z",
"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/62ZLG6SWocs",
"published": "2025-08-30T18:58:23Z",
"content": "no description",
"attachment": {
"type": "Document",
"url": "http://pasture-one-actor/images/100.png"
},
"tag": [
{
"type": "Mention",
"href": "http://gotosocial/users/cookie"
}
]
}
}
gotosocial
{
"id": "01K3Y5GM4R4ZT1R2KD2M7Q0WHN",
"created_at": "2025-08-30T18:58:23.000Z",
"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/62ZLG6SWocs",
"url": "http://pasture-one-actor/object/62ZLG6SWocs",
"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": "01K3Y5DQCATKE3219T6HGE9WRD",
"username": "actor",
"acct": "actor@pasture-one-actor",
"display_name": "Test Actor",
"locked": true,
"discoverable": false,
"bot": false,
"created_at": "2025-08-30T18:56:48.022Z",
"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": 46,
"last_status_at": "2025-08-30T18:58:23.000Z",
"emojis": [],
"fields": []
},
"media_attachments": [
{
"id": "01K3Y5GMM6HYMZD89BDNMJFQSY",
"type": "image",
"url": "http://gotosocial/fileserver/01K3Y5DQCATKE3219T6HGE9WRD/attachment/original/01K3Y5GMM6HYMZD89BDNMJFQSY.png",
"text_url": "http://gotosocial/fileserver/01K3Y5DQCATKE3219T6HGE9WRD/attachment/original/01K3Y5GMM6HYMZD89BDNMJFQSY.png",
"preview_url": "http://gotosocial/fileserver/01K3Y5DQCATKE3219T6HGE9WRD/attachment/small/01K3Y5GMM6HYMZD89BDNMJFQSY.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": "L77;G+pMfQpMpMflfQflfQfQfQfQ"
}
],
"mentions": [
{
"id": "01JWFBJTXM7GDMXXK40GW9WXT9",
"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/S-Z6MAMUPZ4",
"published": "2025-08-30T18:58:24Z",
"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/tbUkRyn_Gzo",
"published": "2025-08-30T18:58:24Z",
"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": "01K3Y5GN408TWCA78B4KXS4998",
"created_at": "2025-08-30T18:58:24.000Z",
"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/tbUkRyn_Gzo",
"url": "http://pasture-one-actor/object/tbUkRyn_Gzo",
"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": "01K3Y5DQCATKE3219T6HGE9WRD",
"username": "actor",
"acct": "actor@pasture-one-actor",
"display_name": "Test Actor",
"locked": true,
"discoverable": false,
"bot": false,
"created_at": "2025-08-30T18:56:48.022Z",
"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": 47,
"last_status_at": "2025-08-30T18:58:24.000Z",
"emojis": [],
"fields": []
},
"media_attachments": [
{
"id": "01K3Y5GN8RX0PVHYAJM4DFS84G",
"type": "image",
"url": "http://gotosocial/fileserver/01K3Y5DQCATKE3219T6HGE9WRD/attachment/original/01K3Y5GN8RX0PVHYAJM4DFS84G.png",
"text_url": "http://gotosocial/fileserver/01K3Y5DQCATKE3219T6HGE9WRD/attachment/original/01K3Y5GN8RX0PVHYAJM4DFS84G.png",
"preview_url": "http://gotosocial/fileserver/01K3Y5DQCATKE3219T6HGE9WRD/attachment/small/01K3Y5GN8RX0PVHYAJM4DFS84G.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": "L6Mb5._JfQ_J_JkBfQkBfQfQfQfQ"
}
],
"mentions": [
{
"id": "01JWFBJTXM7GDMXXK40GW9WXT9",
"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/6F4idW3Z290",
"published": "2025-08-30T18:58:24Z",
"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/VhnMzM_qoAo",
"published": "2025-08-30T18:58:24Z",
"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": "01K3Y5GN40XR0612MDH2B7S5NG",
"created_at": "2025-08-30T18:58:24.000Z",
"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/VhnMzM_qoAo",
"url": "http://pasture-one-actor/object/VhnMzM_qoAo",
"replies_count": 0,
"reblogs_count": 0,
"favourites_count": 0,
"favourited": false,
"reblogged": false,
"muted": false,
"bookmarked": false,
"pinned": false,
"content": "text<hr><p><i lang=\"en\">\u2139\ufe0f Note from gotosocial: 1 attachment in this status could not be downloaded. Treat the following external link with care:</i></p><ul><li><a href=\"http://pasture-one-actor/assets/FediverseLogo.png\" rel=\"nofollow noreferrer noopener\" target=\"_blank\">FediverseLogo.png</a> [name]</li></ul>",
"reblog": null,
"account": {
"id": "01K3Y5DQCATKE3219T6HGE9WRD",
"username": "actor",
"acct": "actor@pasture-one-actor",
"display_name": "Test Actor",
"locked": true,
"discoverable": false,
"bot": false,
"created_at": "2025-08-30T18:56:48.022Z",
"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": 48,
"last_status_at": "2025-08-30T18:58:24.000Z",
"emojis": [],
"fields": []
},
"media_attachments": [],
"mentions": [
{
"id": "01JWFBJTXM7GDMXXK40GW9WXT9",
"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/haColljZ2A8",
"published": "2025-08-30T18:58:25Z",
"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/object/G0Z7yh9sfmY",
"published": "2025-08-30T18:58:25Z",
"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": "01K3Y5GP38KYZP24A17A5KXSA8",
"created_at": "2025-08-30T18:58:25.000Z",
"in_reply_to_id": null,
"in_reply_to_account_id": null,
"sensitive": false,
"spoiler_text": "",
"visibility": "public",
"language": null,
"uri": "http://pasture-one-actor/object/G0Z7yh9sfmY",
"url": "http://pasture-one-actor/object/G0Z7yh9sfmY",
"replies_count": 0,
"reblogs_count": 0,
"favourites_count": 0,
"favourited": false,
"reblogged": false,
"muted": false,
"bookmarked": false,
"pinned": false,
"content": "no comment in attachment<hr><p><i lang=\"en\">\u2139\ufe0f Note from gotosocial: 1 attachment in this status could not be downloaded. Treat the following external link with care:</i></p><ul><li><a href=\"http://pasture-one-actor/assets/FediverseLogo.png\" rel=\"nofollow noreferrer noopener\" target=\"_blank\">FediverseLogo.png</a></li></ul>",
"reblog": null,
"account": {
"id": "01K3Y5DQCATKE3219T6HGE9WRD",
"username": "actor",
"acct": "actor@pasture-one-actor",
"display_name": "Test Actor",
"locked": true,
"discoverable": false,
"bot": false,
"created_at": "2025-08-30T18:56:48.022Z",
"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": 49,
"last_status_at": "2025-08-30T18:58:25.000Z",
"emojis": [],
"fields": []
},
"media_attachments": [],
"mentions": [
{
"id": "01JWFBJTXM7GDMXXK40GW9WXT9",
"username": "cookie",
"url": "http://gotosocial/@cookie",
"acct": "cookie"
}
],
"tags": [],
"emojis": [],
"card": null,
"poll": null
}