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/h4-78ZwtdT0",
"published": "2025-02-25T09:44:03Z",
"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/Trxvn0i-vbg",
"published": "2025-02-25T09:44:03Z",
"content": "no description",
"attachment": {
"type": "Document",
"url": "http://pasture-one-actor/images/100.png"
},
"tag": [
{
"type": "Mention",
"href": "http://gotosocial/users/cookie"
}
]
}
}
gotosocial
{
"id": "01JMY7VXNRPVG1046WBD4RVC1Q",
"created_at": "2025-02-25T09:44:03.000Z",
"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/Trxvn0i-vbg",
"url": "http://pasture-one-actor/actor/Trxvn0i-vbg",
"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": "01JMY7S9J429T866CX8ADF74KA",
"username": "actor",
"acct": "actor@pasture-one-actor",
"display_name": "Test Actor",
"locked": true,
"discoverable": false,
"bot": false,
"created_at": "2025-02-25T09:42:36.879Z",
"note": "",
"url": "http://pasture-one-actor/actor",
"avatar": "http://gotosocial/assets/default_avatars/GoToSocial_icon5.png",
"avatar_static": "http://gotosocial/assets/default_avatars/GoToSocial_icon5.png",
"header": "http://gotosocial/assets/default_header.png",
"header_static": "http://gotosocial/assets/default_header.png",
"followers_count": 0,
"following_count": 0,
"statuses_count": 34,
"last_status_at": "2025-02-25T09:44:03.000Z",
"emojis": [],
"fields": []
},
"media_attachments": [
{
"id": "01JMY7VYCGVZTPFDDM9DK4HKWF",
"type": "image",
"url": "http://gotosocial/fileserver/01JMY7S9J429T866CX8ADF74KA/attachment/original/01JMY7VYCGVZTPFDDM9DK4HKWF.png",
"text_url": "http://gotosocial/fileserver/01JMY7S9J429T866CX8ADF74KA/attachment/original/01JMY7VYCGVZTPFDDM9DK4HKWF.png",
"preview_url": "http://gotosocial/fileserver/01JMY7S9J429T866CX8ADF74KA/attachment/small/01JMY7VYCGVZTPFDDM9DK4HKWF.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": "L6OGD#|wfQ|w|wo1fQo1fQfQfQfQ"
}
],
"mentions": [
{
"id": "01TKSVTDBGVRGHD2D2KRWWANGD",
"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/smrP6HTW6Qs",
"published": "2025-02-25T09:44:04Z",
"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/d4eyU_1DSJA",
"published": "2025-02-25T09:44:04Z",
"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": "01JMY7VYN0DKP8VSP5SWYZV9VW",
"created_at": "2025-02-25T09:44:04.000Z",
"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/d4eyU_1DSJA",
"url": "http://pasture-one-actor/actor/d4eyU_1DSJA",
"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": "01JMY7S9J429T866CX8ADF74KA",
"username": "actor",
"acct": "actor@pasture-one-actor",
"display_name": "Test Actor",
"locked": true,
"discoverable": false,
"bot": false,
"created_at": "2025-02-25T09:42:36.879Z",
"note": "",
"url": "http://pasture-one-actor/actor",
"avatar": "http://gotosocial/assets/default_avatars/GoToSocial_icon5.png",
"avatar_static": "http://gotosocial/assets/default_avatars/GoToSocial_icon5.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": "2025-02-25T09:44:04.000Z",
"emojis": [],
"fields": []
},
"media_attachments": [
{
"id": "01JMY7VZ1DWHG24R1JKTMT0WVG",
"type": "image",
"url": "http://gotosocial/fileserver/01JMY7S9J429T866CX8ADF74KA/attachment/original/01JMY7VZ1DWHG24R1JKTMT0WVG.png",
"text_url": "http://gotosocial/fileserver/01JMY7S9J429T866CX8ADF74KA/attachment/original/01JMY7VZ1DWHG24R1JKTMT0WVG.png",
"preview_url": "http://gotosocial/fileserver/01JMY7S9J429T866CX8ADF74KA/attachment/small/01JMY7VZ1DWHG24R1JKTMT0WVG.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": "L76Ew.q7fQq7q7f%fQf%fQfQfQfQ"
}
],
"mentions": [
{
"id": "01TKSVTDBGVRGHD2D2KRWWANGD",
"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/K9J51qIVBYY",
"published": "2025-02-25T09:44:04Z",
"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/AtKJSTisK0c",
"published": "2025-02-25T09:44:04Z",
"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": "01JMY7VYN0Z2J0QQVDP91S342D",
"created_at": "2025-02-25T09:44:04.000Z",
"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/AtKJSTisK0c",
"url": "http://pasture-one-actor/actor/AtKJSTisK0c",
"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": "01JMY7S9J429T866CX8ADF74KA",
"username": "actor",
"acct": "actor@pasture-one-actor",
"display_name": "Test Actor",
"locked": true,
"discoverable": false,
"bot": false,
"created_at": "2025-02-25T09:42:36.879Z",
"note": "",
"url": "http://pasture-one-actor/actor",
"avatar": "http://gotosocial/assets/default_avatars/GoToSocial_icon5.png",
"avatar_static": "http://gotosocial/assets/default_avatars/GoToSocial_icon5.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": "2025-02-25T09:44:04.000Z",
"emojis": [],
"fields": []
},
"media_attachments": [
{
"id": "01JMY7VZP98VA3N8XD2607VV1Y",
"type": "image",
"url": "http://gotosocial/fileserver/01JMY7S9J429T866CX8ADF74KA/attachment/original/01JMY7VZP98VA3N8XD2607VV1Y.png",
"text_url": "http://gotosocial/fileserver/01JMY7S9J429T866CX8ADF74KA/attachment/original/01JMY7VZP98VA3N8XD2607VV1Y.png",
"preview_url": "http://gotosocial/fileserver/01JMY7S9J429T866CX8ADF74KA/attachment/small/01JMY7VZP98VA3N8XD2607VV1Y.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": "01TKSVTDBGVRGHD2D2KRWWANGD",
"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/rHKESYKrfwk",
"published": "2025-02-25T09:44:05Z",
"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/65s3Jr-c428",
"published": "2025-02-25T09:44:05Z",
"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": "01JMY7VZM8F03J8DCFG1VEVQ4N",
"created_at": "2025-02-25T09:44:05.000Z",
"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/65s3Jr-c428",
"url": "http://pasture-one-actor/actor/65s3Jr-c428",
"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": "01JMY7S9J429T866CX8ADF74KA",
"username": "actor",
"acct": "actor@pasture-one-actor",
"display_name": "Test Actor",
"locked": true,
"discoverable": false,
"bot": false,
"created_at": "2025-02-25T09:42:36.879Z",
"note": "",
"url": "http://pasture-one-actor/actor",
"avatar": "http://gotosocial/assets/default_avatars/GoToSocial_icon5.png",
"avatar_static": "http://gotosocial/assets/default_avatars/GoToSocial_icon5.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": "2025-02-25T09:44:05.000Z",
"emojis": [],
"fields": []
},
"media_attachments": [
{
"id": "01JMY7W0C3D1CMQ8RTK0Y7JBRX",
"type": "image",
"url": "http://gotosocial/fileserver/01JMY7S9J429T866CX8ADF74KA/attachment/original/01JMY7W0C3D1CMQ8RTK0Y7JBRX.png",
"text_url": "http://gotosocial/fileserver/01JMY7S9J429T866CX8ADF74KA/attachment/original/01JMY7W0C3D1CMQ8RTK0Y7JBRX.png",
"preview_url": "http://gotosocial/fileserver/01JMY7S9J429T866CX8ADF74KA/attachment/small/01JMY7W0C3D1CMQ8RTK0Y7JBRX.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": "01TKSVTDBGVRGHD2D2KRWWANGD",
"username": "cookie",
"url": "http://gotosocial/@cookie",
"acct": "cookie"
}
],
"tags": [],
"emojis": [],
"card": null,
"poll": null
}