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/activity/uOTkiYk9F7A",
"published": "2025-08-15T10:08:38Z",
"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/yCf47LQbbHQ",
"published": "2025-08-15T10:08:38Z",
"content": "no description",
"attachment": {
"type": "Document",
"url": "http://pasture-one-actor/images/100.png"
},
"tag": [
{
"type": "Mention",
"href": "http://gotosocial/users/cookie"
}
]
}
}
gotosocial
{
"id": "01K2PK7V3GM9DR6B8AE8NXQBC8",
"created_at": "2025-08-15T10:08:38.000Z",
"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/yCf47LQbbHQ",
"url": "http://pasture-one-actor/object/yCf47LQbbHQ",
"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": "01K2PK570GR1SPGEKVD44YKHSF",
"username": "actor",
"acct": "actor@pasture-one-actor",
"display_name": "Test Actor",
"locked": true,
"discoverable": false,
"bot": false,
"created_at": "2025-08-15T10:07:11.900Z",
"note": "",
"url": "http://pasture-one-actor/actor",
"avatar": "http://gotosocial/assets/default_avatars/GoToSocial_icon1.png",
"avatar_static": "http://gotosocial/assets/default_avatars/GoToSocial_icon1.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": "2025-08-15T10:08:38.000Z",
"emojis": [],
"fields": []
},
"media_attachments": [
{
"id": "01K2PK7VZGSG0D32Q2NRV87Y6Q",
"type": "image",
"url": "http://gotosocial/fileserver/01K2PK570GR1SPGEKVD44YKHSF/attachment/original/01K2PK7VZGSG0D32Q2NRV87Y6Q.png",
"text_url": "http://gotosocial/fileserver/01K2PK570GR1SPGEKVD44YKHSF/attachment/original/01K2PK7VZGSG0D32Q2NRV87Y6Q.png",
"preview_url": "http://gotosocial/fileserver/01K2PK570GR1SPGEKVD44YKHSF/attachment/small/01K2PK7VZGSG0D32Q2NRV87Y6Q.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": "L51]c~l%fQl%l%f*fQf*fQfQfQfQ"
}
],
"mentions": [
{
"id": "01XMTC72S3W0BJ27XEVBSF1W9Z",
"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/activity/gvNhdJbHr9w",
"published": "2025-08-15T10:08:39Z",
"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/xcMLq2zFeX0",
"published": "2025-08-15T10:08:39Z",
"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": "01K2PK7W2RV6B80VQ0DTY777RS",
"created_at": "2025-08-15T10:08:39.000Z",
"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/xcMLq2zFeX0",
"url": "http://pasture-one-actor/object/xcMLq2zFeX0",
"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": "01K2PK570GR1SPGEKVD44YKHSF",
"username": "actor",
"acct": "actor@pasture-one-actor",
"display_name": "Test Actor",
"locked": true,
"discoverable": false,
"bot": false,
"created_at": "2025-08-15T10:07:11.900Z",
"note": "",
"url": "http://pasture-one-actor/actor",
"avatar": "http://gotosocial/assets/default_avatars/GoToSocial_icon1.png",
"avatar_static": "http://gotosocial/assets/default_avatars/GoToSocial_icon1.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": "2025-08-15T10:08:39.000Z",
"emojis": [],
"fields": []
},
"media_attachments": [
{
"id": "01K2PK7WMQYAAHW84K22BFKC9D",
"type": "image",
"url": "http://gotosocial/fileserver/01K2PK570GR1SPGEKVD44YKHSF/attachment/original/01K2PK7WMQYAAHW84K22BFKC9D.png",
"text_url": "http://gotosocial/fileserver/01K2PK570GR1SPGEKVD44YKHSF/attachment/original/01K2PK7WMQYAAHW84K22BFKC9D.png",
"preview_url": "http://gotosocial/fileserver/01K2PK570GR1SPGEKVD44YKHSF/attachment/small/01K2PK7WMQYAAHW84K22BFKC9D.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": "L3215ClofQloloflfQflfQfQfQfQ"
}
],
"mentions": [
{
"id": "01XMTC72S3W0BJ27XEVBSF1W9Z",
"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/activity/RbDVPt106ms",
"published": "2025-08-15T10:08:40Z",
"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/L5pp3izeAb8",
"published": "2025-08-15T10:08:40Z",
"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": "01K2PK7X205RE75C8Z6VYQQ0JB",
"created_at": "2025-08-15T10:08:40.000Z",
"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/L5pp3izeAb8",
"url": "http://pasture-one-actor/object/L5pp3izeAb8",
"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": "01K2PK570GR1SPGEKVD44YKHSF",
"username": "actor",
"acct": "actor@pasture-one-actor",
"display_name": "Test Actor",
"locked": true,
"discoverable": false,
"bot": false,
"created_at": "2025-08-15T10:07:11.900Z",
"note": "",
"url": "http://pasture-one-actor/actor",
"avatar": "http://gotosocial/assets/default_avatars/GoToSocial_icon1.png",
"avatar_static": "http://gotosocial/assets/default_avatars/GoToSocial_icon1.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": "2025-08-15T10:08:40.000Z",
"emojis": [],
"fields": []
},
"media_attachments": [],
"mentions": [
{
"id": "01XMTC72S3W0BJ27XEVBSF1W9Z",
"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/activity/GpmSLCNf5hU",
"published": "2025-08-15T10:08:40Z",
"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/Vyazg65-_eM",
"published": "2025-08-15T10:08:40Z",
"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": "01K2PK7X20J56MH7234DZPD026",
"created_at": "2025-08-15T10:08:40.000Z",
"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/Vyazg65-_eM",
"url": "http://pasture-one-actor/object/Vyazg65-_eM",
"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": "01K2PK570GR1SPGEKVD44YKHSF",
"username": "actor",
"acct": "actor@pasture-one-actor",
"display_name": "Test Actor",
"locked": true,
"discoverable": false,
"bot": false,
"created_at": "2025-08-15T10:07:11.900Z",
"note": "",
"url": "http://pasture-one-actor/actor",
"avatar": "http://gotosocial/assets/default_avatars/GoToSocial_icon1.png",
"avatar_static": "http://gotosocial/assets/default_avatars/GoToSocial_icon1.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": "2025-08-15T10:08:40.000Z",
"emojis": [],
"fields": []
},
"media_attachments": [],
"mentions": [
{
"id": "01XMTC72S3W0BJ27XEVBSF1W9Z",
"username": "cookie",
"url": "http://gotosocial/@cookie",
"acct": "cookie"
}
],
"tags": [],
"emojis": [],
"card": null,
"poll": null
}