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. misskey, 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/DyAk3IwIsTY",
"published": "2025-11-21T13:04:22Z",
"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/vBmFMcUmiNs",
"published": "2025-11-21T13:04:22Z",
"content": "no description",
"attachment": {
"type": "Image",
"url": "http://pasture-one-actor/images/51b7b878-56cf-407c-b9aa-825976e8858d.png"
},
"tag": [
{
"type": "Mention",
"href": "http://gotosocial/users/cookie"
}
]
}
}
gotosocial
{
"id": "01KAK881ZGJZC56QDKKQBBJTKH",
"created_at": "2025-11-21T13:04:22.000Z",
"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/vBmFMcUmiNs",
"url": "http://pasture-one-actor/object/vBmFMcUmiNs",
"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": "01KAK84S6SGKYKYKR2H78C5KSF",
"username": "actor",
"acct": "actor@pasture-one-actor",
"display_name": "Test Actor",
"locked": true,
"discoverable": false,
"bot": false,
"created_at": "2025-11-21T13:02:34.736Z",
"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": 75,
"last_status_at": "2025-11-21T13:04:22.000Z",
"emojis": [],
"fields": []
},
"media_attachments": [
{
"id": "01KAK882BA37K19GDQ4CTSZTMS",
"type": "image",
"url": "http://gotosocial/fileserver/01KAK84S6SGKYKYKR2H78C5KSF/attachment/original/01KAK882BA37K19GDQ4CTSZTMS.png",
"text_url": "http://gotosocial/fileserver/01KAK84S6SGKYKYKR2H78C5KSF/attachment/original/01KAK882BA37K19GDQ4CTSZTMS.png",
"preview_url": "http://gotosocial/fileserver/01KAK84S6SGKYKYKR2H78C5KSF/attachment/small/01KAK882BA37K19GDQ4CTSZTMS.jpg",
"remote_url": "http://pasture-one-actor/images/51b7b878-56cf-407c-b9aa-825976e8858d.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": "L01y@wo,fQo,o,flfQflfQfQfQfQ"
}
],
"mentions": [
{
"id": "01EW65M4VPKBKHDASXNJ8B2E0A",
"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/v5gw2SmStgU",
"published": "2025-11-21T13:04:22Z",
"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/f28j0dN9JrI",
"published": "2025-11-21T13:04:22Z",
"content": "name, summary and content",
"attachment": {
"type": "Image",
"url": "http://pasture-one-actor/images/d8dacd26-3703-4957-b882-b27b857749f1.png",
"name": "name",
"summary": "summary",
"content": "content"
},
"tag": [
{
"type": "Mention",
"href": "http://gotosocial/users/cookie"
}
]
}
}
gotosocial
{
"id": "01KAK881ZGF45X82SBBA9B8FKZ",
"created_at": "2025-11-21T13:04:22.000Z",
"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/f28j0dN9JrI",
"url": "http://pasture-one-actor/object/f28j0dN9JrI",
"replies_count": 0,
"reblogs_count": 0,
"favourites_count": 0,
"favourited": false,
"reblogged": false,
"muted": false,
"bookmarked": false,
"pinned": false,
"content": "name, summary and content",
"reblog": null,
"account": {
"id": "01KAK84S6SGKYKYKR2H78C5KSF",
"username": "actor",
"acct": "actor@pasture-one-actor",
"display_name": "Test Actor",
"locked": true,
"discoverable": false,
"bot": false,
"created_at": "2025-11-21T13:02:34.736Z",
"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": 76,
"last_status_at": "2025-11-21T13:04:22.000Z",
"emojis": [],
"fields": []
},
"media_attachments": [
{
"id": "01KAK882WEEHQ5BSARCT6KBRTK",
"type": "image",
"url": "http://gotosocial/fileserver/01KAK84S6SGKYKYKR2H78C5KSF/attachment/original/01KAK882WEEHQ5BSARCT6KBRTK.png",
"text_url": "http://gotosocial/fileserver/01KAK84S6SGKYKYKR2H78C5KSF/attachment/original/01KAK882WEEHQ5BSARCT6KBRTK.png",
"preview_url": "http://gotosocial/fileserver/01KAK84S6SGKYKYKR2H78C5KSF/attachment/small/01KAK882WEEHQ5BSARCT6KBRTK.jpg",
"remote_url": "http://pasture-one-actor/images/d8dacd26-3703-4957-b882-b27b857749f1.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": "L01MaFo+fQo+o+fRfQfRfQfQfQfQ"
}
],
"mentions": [
{
"id": "01EW65M4VPKBKHDASXNJ8B2E0A",
"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/c64YvEn0iJg",
"published": "2025-11-21T13:04:23Z",
"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/mk5cazTkfiE",
"published": "2025-11-21T13:04:23Z",
"content": "only name",
"attachment": [
{
"type": "Image",
"url": "http://pasture-one-actor/assets/FediverseLogo.png",
"name": "name",
"imageType": "image/jpeg"
}
],
"tag": [
{
"type": "Mention",
"href": "http://gotosocial/users/cookie"
}
]
}
}
gotosocial
{
"id": "01KAK882YRXH12NJFXRB0ZKXWX",
"created_at": "2025-11-21T13:04:23.000Z",
"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/mk5cazTkfiE",
"url": "http://pasture-one-actor/object/mk5cazTkfiE",
"replies_count": 0,
"reblogs_count": 0,
"favourites_count": 0,
"favourited": false,
"reblogged": false,
"muted": false,
"bookmarked": false,
"pinned": false,
"content": "only name",
"reblog": null,
"account": {
"id": "01KAK84S6SGKYKYKR2H78C5KSF",
"username": "actor",
"acct": "actor@pasture-one-actor",
"display_name": "Test Actor",
"locked": true,
"discoverable": false,
"bot": false,
"created_at": "2025-11-21T13:02:34.736Z",
"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": 77,
"last_status_at": "2025-11-21T13:04:23.000Z",
"emojis": [],
"fields": []
},
"media_attachments": [
{
"id": "01KAK883EA8E71RSRNAXFFAGJ2",
"type": "image",
"url": "http://gotosocial/fileserver/01KAK84S6SGKYKYKR2H78C5KSF/attachment/original/01KAK883EA8E71RSRNAXFFAGJ2.png",
"text_url": "http://gotosocial/fileserver/01KAK84S6SGKYKYKR2H78C5KSF/attachment/original/01KAK883EA8E71RSRNAXFFAGJ2.png",
"preview_url": "http://gotosocial/fileserver/01KAK84S6SGKYKYKR2H78C5KSF/attachment/small/01KAK883EA8E71RSRNAXFFAGJ2.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": "01EW65M4VPKBKHDASXNJ8B2E0A",
"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/VQZGvkaFChM",
"published": "2025-11-21T13:04:24Z",
"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/NDzCtCFmmY8",
"published": "2025-11-21T13:04:24Z",
"content": "only summary",
"attachment": {
"type": "Image",
"url": "http://pasture-one-actor/images/f928e63c-448f-4c9a-932c-b70eaed46d10.png",
"summary": "summary"
},
"tag": [
{
"type": "Mention",
"href": "http://gotosocial/users/cookie"
}
]
}
}
gotosocial
{
"id": "01KAK883Y06DSK82QGFHX8M21K",
"created_at": "2025-11-21T13:04:24.000Z",
"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/NDzCtCFmmY8",
"url": "http://pasture-one-actor/object/NDzCtCFmmY8",
"replies_count": 0,
"reblogs_count": 0,
"favourites_count": 0,
"favourited": false,
"reblogged": false,
"muted": false,
"bookmarked": false,
"pinned": false,
"content": "only summary",
"reblog": null,
"account": {
"id": "01KAK84S6SGKYKYKR2H78C5KSF",
"username": "actor",
"acct": "actor@pasture-one-actor",
"display_name": "Test Actor",
"locked": true,
"discoverable": false,
"bot": false,
"created_at": "2025-11-21T13:02:34.736Z",
"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": 78,
"last_status_at": "2025-11-21T13:04:24.000Z",
"emojis": [],
"fields": []
},
"media_attachments": [
{
"id": "01KAK8840YZ8SRYAD4QAZPBG79",
"type": "image",
"url": "http://gotosocial/fileserver/01KAK84S6SGKYKYKR2H78C5KSF/attachment/original/01KAK8840YZ8SRYAD4QAZPBG79.png",
"text_url": "http://gotosocial/fileserver/01KAK84S6SGKYKYKR2H78C5KSF/attachment/original/01KAK8840YZ8SRYAD4QAZPBG79.png",
"preview_url": "http://gotosocial/fileserver/01KAK84S6SGKYKYKR2H78C5KSF/attachment/small/01KAK8840YZ8SRYAD4QAZPBG79.jpg",
"remote_url": "http://pasture-one-actor/images/f928e63c-448f-4c9a-932c-b70eaed46d10.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": "L8Q?o{}pfQ}p}poKfQoKfQfQfQfQ"
}
],
"mentions": [
{
"id": "01EW65M4VPKBKHDASXNJ8B2E0A",
"username": "cookie",
"url": "http://gotosocial/@cookie",
"acct": "cookie"
}
],
"tags": [],
"emojis": [],
"card": null,
"poll": null
}
Example 5¶
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/KYpp9Xf4Qw4",
"published": "2025-11-21T13:04:24Z",
"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/glfoqHKM6Jc",
"published": "2025-11-21T13:04:24Z",
"content": "only content",
"attachment": {
"type": "Image",
"url": "http://pasture-one-actor/images/f437a0ab-f24a-4a89-8a92-298c09905940.png",
"content": "content"
},
"tag": [
{
"type": "Mention",
"href": "http://gotosocial/users/cookie"
}
]
}
}
gotosocial
{
"id": "01KAK883Y0WX18CW846MRG332M",
"created_at": "2025-11-21T13:04:24.000Z",
"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/glfoqHKM6Jc",
"url": "http://pasture-one-actor/object/glfoqHKM6Jc",
"replies_count": 0,
"reblogs_count": 0,
"favourites_count": 0,
"favourited": false,
"reblogged": false,
"muted": false,
"bookmarked": false,
"pinned": false,
"content": "only content",
"reblog": null,
"account": {
"id": "01KAK84S6SGKYKYKR2H78C5KSF",
"username": "actor",
"acct": "actor@pasture-one-actor",
"display_name": "Test Actor",
"locked": true,
"discoverable": false,
"bot": false,
"created_at": "2025-11-21T13:02:34.736Z",
"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": 79,
"last_status_at": "2025-11-21T13:04:24.000Z",
"emojis": [],
"fields": []
},
"media_attachments": [
{
"id": "01KAK884JE6M6B4S3CT15MJ6DW",
"type": "image",
"url": "http://gotosocial/fileserver/01KAK84S6SGKYKYKR2H78C5KSF/attachment/original/01KAK884JE6M6B4S3CT15MJ6DW.png",
"text_url": "http://gotosocial/fileserver/01KAK84S6SGKYKYKR2H78C5KSF/attachment/original/01KAK884JE6M6B4S3CT15MJ6DW.png",
"preview_url": "http://gotosocial/fileserver/01KAK84S6SGKYKYKR2H78C5KSF/attachment/small/01KAK884JE6M6B4S3CT15MJ6DW.jpg",
"remote_url": "http://pasture-one-actor/images/f437a0ab-f24a-4a89-8a92-298c09905940.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": "L5J~m?^UfQ^U^Uj]fQj]fQfQfQfQ"
}
],
"mentions": [
{
"id": "01EW65M4VPKBKHDASXNJ8B2E0A",
"username": "cookie",
"url": "http://gotosocial/@cookie",
"acct": "cookie"
}
],
"tags": [],
"emojis": [],
"card": null,
"poll": null
}
Example 6¶
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/2THHQeG6_qw",
"published": "2025-11-21T13:04:25Z",
"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/b2KxA43VaRQ",
"published": "2025-11-21T13:04:25Z",
"content": "no comment in attachment; reused image",
"attachment": [
{
"type": "Image",
"url": "http://pasture-one-actor/assets/FediverseLogo.png"
}
],
"tag": [
{
"type": "Mention",
"href": "http://gotosocial/users/cookie"
}
]
}
}
gotosocial
{
"id": "01KAK884X8MQ7XR5M51M68R626",
"created_at": "2025-11-21T13:04:25.000Z",
"in_reply_to_id": null,
"in_reply_to_account_id": null,
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