Hashtags

The following mostly illustrates how the name of a hashtag gets transformed by the applications. The input has the form

"tag": {"type": "Hashtag", "name": "${tag}"}

The last two examples illustrate more technical behavior. For particularities in parsing see Hashtags and JSON-LD.

Support Table Preview

tag	Object	Activity
#test	Object	Activity
nohash	Object	Activity
#with-dash_under	Object	Activity
#with white space	Object	Activity
#with(subtag)	Object	Activity
#with123	Object	Activity
#1234	Object	Activity
#CamelCase	Object	Activity
#ümläütß	Object	Activity
#🐄	Object	Activity
#❤️	Object	Activity
#牛	Object	Activity
#test broken url parameter	Object	Activity

Objects

Object 1

{
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    {
      "Hashtag": "as:Hashtag",
      "sensitive": "as:sensitive"
    }
  ],
  "attributedTo": "http://actor.example",
  "content": "text",
  "id": "http://actor.example/object/WAsoQ2C2uT4",
  "published": "2025-09-09T09:32:39Z",
  "tag": {
    "name": "#test",
    "type": "Hashtag"
  },
  "to": [
    "https://www.w3.org/ns/activitystreams#Public"
  ],
  "type": "Note"
}

Object 2

{
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    {
      "Hashtag": "as:Hashtag",
      "sensitive": "as:sensitive"
    }
  ],
  "attributedTo": "http://actor.example",
  "content": "text",
  "id": "http://actor.example/object/QY_vKGBlXac",
  "published": "2025-09-09T09:32:39Z",
  "tag": {
    "name": "nohash",
    "type": "Hashtag"
  },
  "to": [
    "https://www.w3.org/ns/activitystreams#Public"
  ],
  "type": "Note"
}

Object 3

{
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    {
      "Hashtag": "as:Hashtag",
      "sensitive": "as:sensitive"
    }
  ],
  "attributedTo": "http://actor.example",
  "content": "text",
  "id": "http://actor.example/object/TzdURkAm-FU",
  "published": "2025-09-09T09:32:39Z",
  "tag": {
    "name": "#with-dash_under",
    "type": "Hashtag"
  },
  "to": [
    "https://www.w3.org/ns/activitystreams#Public"
  ],
  "type": "Note"
}

Object 4

{
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    {
      "Hashtag": "as:Hashtag",
      "sensitive": "as:sensitive"
    }
  ],
  "attributedTo": "http://actor.example",
  "content": "text",
  "id": "http://actor.example/object/9nyIbrZl30Q",
  "published": "2025-09-09T09:32:39Z",
  "tag": {
    "name": "#with white space",
    "type": "Hashtag"
  },
  "to": [
    "https://www.w3.org/ns/activitystreams#Public"
  ],
  "type": "Note"
}

Object 5

{
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    {
      "Hashtag": "as:Hashtag",
      "sensitive": "as:sensitive"
    }
  ],
  "attributedTo": "http://actor.example",
  "content": "text",
  "id": "http://actor.example/object/5j5Nnx8-fiw",
  "published": "2025-09-09T09:32:39Z",
  "tag": {
    "name": "#with(subtag)",
    "type": "Hashtag"
  },
  "to": [
    "https://www.w3.org/ns/activitystreams#Public"
  ],
  "type": "Note"
}

Object 6

{
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    {
      "Hashtag": "as:Hashtag",
      "sensitive": "as:sensitive"
    }
  ],
  "attributedTo": "http://actor.example",
  "content": "text",
  "id": "http://actor.example/object/aWrHvVGwEvs",
  "published": "2025-09-09T09:32:39Z",
  "tag": {
    "name": "#with123",
    "type": "Hashtag"
  },
  "to": [
    "https://www.w3.org/ns/activitystreams#Public"
  ],
  "type": "Note"
}

Object 7

{
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    {
      "Hashtag": "as:Hashtag",
      "sensitive": "as:sensitive"
    }
  ],
  "attributedTo": "http://actor.example",
  "content": "text",
  "id": "http://actor.example/object/47EfJucw1DU",
  "published": "2025-09-09T09:32:39Z",
  "tag": {
    "name": "#1234",
    "type": "Hashtag"
  },
  "to": [
    "https://www.w3.org/ns/activitystreams#Public"
  ],
  "type": "Note"
}

Object 8

{
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    {
      "Hashtag": "as:Hashtag",
      "sensitive": "as:sensitive"
    }
  ],
  "attributedTo": "http://actor.example",
  "content": "text",
  "id": "http://actor.example/object/LNe3ZP2NShM",
  "published": "2025-09-09T09:32:39Z",
  "tag": {
    "name": "#CamelCase",
    "type": "Hashtag"
  },
  "to": [
    "https://www.w3.org/ns/activitystreams#Public"
  ],
  "type": "Note"
}

Object 9

{
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    {
      "Hashtag": "as:Hashtag",
      "sensitive": "as:sensitive"
    }
  ],
  "attributedTo": "http://actor.example",
  "content": "text",
  "id": "http://actor.example/object/L32aqWbmhsA",
  "published": "2025-09-09T09:32:39Z",
  "tag": {
    "name": "#\u00fcml\u00e4\u00fct\u00df",
    "type": "Hashtag"
  },
  "to": [
    "https://www.w3.org/ns/activitystreams#Public"
  ],
  "type": "Note"
}

Object 10

{
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    {
      "Hashtag": "as:Hashtag",
      "sensitive": "as:sensitive"
    }
  ],
  "attributedTo": "http://actor.example",
  "content": "text",
  "id": "http://actor.example/object/mfhV7OqE4Ns",
  "published": "2025-09-09T09:32:39Z",
  "tag": {
    "name": "#\ud83d\udc04",
    "type": "Hashtag"
  },
  "to": [
    "https://www.w3.org/ns/activitystreams#Public"
  ],
  "type": "Note"
}

Object 11

{
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    {
      "Hashtag": "as:Hashtag",
      "sensitive": "as:sensitive"
    }
  ],
  "attributedTo": "http://actor.example",
  "content": "text",
  "id": "http://actor.example/object/sD1t9PxwI6Y",
  "published": "2025-09-09T09:32:39Z",
  "tag": {
    "name": "#\u2764\ufe0f",
    "type": "Hashtag"
  },
  "to": [
    "https://www.w3.org/ns/activitystreams#Public"
  ],
  "type": "Note"
}

Object 12

{
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    {
      "Hashtag": "as:Hashtag",
      "sensitive": "as:sensitive"
    }
  ],
  "attributedTo": "http://actor.example",
  "content": "text",
  "id": "http://actor.example/object/_upTWQoPT7U",
  "published": "2025-09-09T09:32:39Z",
  "tag": {
    "name": "#\u725b",
    "type": "Hashtag"
  },
  "to": [
    "https://www.w3.org/ns/activitystreams#Public"
  ],
  "type": "Note"
}

Object 13

{
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    {
      "Hashtag": "as:Hashtag",
      "sensitive": "as:sensitive"
    }
  ],
  "attributedTo": "http://actor.example",
  "content": "broken url parameter",
  "id": "http://actor.example/object/uVMpM9heXM4",
  "published": "2025-09-09T09:32:39Z",
  "tag": {
    "name": "#test",
    "type": "Hashtag",
    "url": "https://ignore.example"
  },
  "to": [
    "https://www.w3.org/ns/activitystreams#Public"
  ],
  "type": "Note"
}

Activities

Activity 1

{
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    {
      "Hashtag": "as:Hashtag",
      "sensitive": "as:sensitive"
    }
  ],
  "actor": "http://actor.example",
  "id": "http://actor.example/activity/W5MV0BZSOU8",
  "object": {
    "attributedTo": "http://actor.example",
    "content": "text",
    "id": "http://actor.example/object/7rkrbNLuSA4",
    "published": "2025-09-09T09:32:39Z",
    "tag": {
      "name": "#test",
      "type": "Hashtag"
    },
    "to": [
      "https://www.w3.org/ns/activitystreams#Public",
      "http://remote.example/"
    ],
    "type": "Note"
  },
  "published": "2025-09-09T09:32:39Z",
  "to": [
    "https://www.w3.org/ns/activitystreams#Public",
    "http://remote.example/"
  ],
  "type": "Create"
}

Activity 2

{
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    {
      "Hashtag": "as:Hashtag",
      "sensitive": "as:sensitive"
    }
  ],
  "actor": "http://actor.example",
  "id": "http://actor.example/activity/41oRAR01q3A",
  "object": {
    "attributedTo": "http://actor.example",
    "content": "text",
    "id": "http://actor.example/object/ipVK6bN5ARI",
    "published": "2025-09-09T09:32:39Z",
    "tag": {
      "name": "nohash",
      "type": "Hashtag"
    },
    "to": [
      "https://www.w3.org/ns/activitystreams#Public",
      "http://remote.example/"
    ],
    "type": "Note"
  },
  "published": "2025-09-09T09:32:39Z",
  "to": [
    "https://www.w3.org/ns/activitystreams#Public",
    "http://remote.example/"
  ],
  "type": "Create"
}

Activity 3

{
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    {
      "Hashtag": "as:Hashtag",
      "sensitive": "as:sensitive"
    }
  ],
  "actor": "http://actor.example",
  "id": "http://actor.example/activity/Hm6gZiqDZCg",
  "object": {
    "attributedTo": "http://actor.example",
    "content": "text",
    "id": "http://actor.example/object/2IIVvSMvvfA",
    "published": "2025-09-09T09:32:39Z",
    "tag": {
      "name": "#with-dash_under",
      "type": "Hashtag"
    },
    "to": [
      "https://www.w3.org/ns/activitystreams#Public",
      "http://remote.example/"
    ],
    "type": "Note"
  },
  "published": "2025-09-09T09:32:39Z",
  "to": [
    "https://www.w3.org/ns/activitystreams#Public",
    "http://remote.example/"
  ],
  "type": "Create"
}

Activity 4

{
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    {
      "Hashtag": "as:Hashtag",
      "sensitive": "as:sensitive"
    }
  ],
  "actor": "http://actor.example",
  "id": "http://actor.example/activity/Td5_JmyqeRQ",
  "object": {
    "attributedTo": "http://actor.example",
    "content": "text",
    "id": "http://actor.example/object/UYIj87bF4-I",
    "published": "2025-09-09T09:32:39Z",
    "tag": {
      "name": "#with white space",
      "type": "Hashtag"
    },
    "to": [
      "https://www.w3.org/ns/activitystreams#Public",
      "http://remote.example/"
    ],
    "type": "Note"
  },
  "published": "2025-09-09T09:32:39Z",
  "to": [
    "https://www.w3.org/ns/activitystreams#Public",
    "http://remote.example/"
  ],
  "type": "Create"
}

Activity 5

{
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    {
      "Hashtag": "as:Hashtag",
      "sensitive": "as:sensitive"
    }
  ],
  "actor": "http://actor.example",
  "id": "http://actor.example/activity/7-0G-6hKufE",
  "object": {
    "attributedTo": "http://actor.example",
    "content": "text",
    "id": "http://actor.example/object/AI4-Y4_EdKo",
    "published": "2025-09-09T09:32:39Z",
    "tag": {
      "name": "#with(subtag)",
      "type": "Hashtag"
    },
    "to": [
      "https://www.w3.org/ns/activitystreams#Public",
      "http://remote.example/"
    ],
    "type": "Note"
  },
  "published": "2025-09-09T09:32:39Z",
  "to": [
    "https://www.w3.org/ns/activitystreams#Public",
    "http://remote.example/"
  ],
  "type": "Create"
}

Activity 6

{
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    {
      "Hashtag": "as:Hashtag",
      "sensitive": "as:sensitive"
    }
  ],
  "actor": "http://actor.example",
  "id": "http://actor.example/activity/0xhaQOyHKrs",
  "object": {
    "attributedTo": "http://actor.example",
    "content": "text",
    "id": "http://actor.example/object/8o6F6fAjSl0",
    "published": "2025-09-09T09:32:39Z",
    "tag": {
      "name": "#with123",
      "type": "Hashtag"
    },
    "to": [
      "https://www.w3.org/ns/activitystreams#Public",
      "http://remote.example/"
    ],
    "type": "Note"
  },
  "published": "2025-09-09T09:32:39Z",
  "to": [
    "https://www.w3.org/ns/activitystreams#Public",
    "http://remote.example/"
  ],
  "type": "Create"
}

Activity 7

{
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    {
      "Hashtag": "as:Hashtag",
      "sensitive": "as:sensitive"
    }
  ],
  "actor": "http://actor.example",
  "id": "http://actor.example/activity/EmUKjZ_ZZiM",
  "object": {
    "attributedTo": "http://actor.example",
    "content": "text",
    "id": "http://actor.example/object/rDnn8nTwbvw",
    "published": "2025-09-09T09:32:39Z",
    "tag": {
      "name": "#1234",
      "type": "Hashtag"
    },
    "to": [
      "https://www.w3.org/ns/activitystreams#Public",
      "http://remote.example/"
    ],
    "type": "Note"
  },
  "published": "2025-09-09T09:32:39Z",
  "to": [
    "https://www.w3.org/ns/activitystreams#Public",
    "http://remote.example/"
  ],
  "type": "Create"
}

Activity 8

{
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    {
      "Hashtag": "as:Hashtag",
      "sensitive": "as:sensitive"
    }
  ],
  "actor": "http://actor.example",
  "id": "http://actor.example/activity/XaS8gixOLZg",
  "object": {
    "attributedTo": "http://actor.example",
    "content": "text",
    "id": "http://actor.example/object/kTJC991aqOY",
    "published": "2025-09-09T09:32:39Z",
    "tag": {
      "name": "#CamelCase",
      "type": "Hashtag"
    },
    "to": [
      "https://www.w3.org/ns/activitystreams#Public",
      "http://remote.example/"
    ],
    "type": "Note"
  },
  "published": "2025-09-09T09:32:39Z",
  "to": [
    "https://www.w3.org/ns/activitystreams#Public",
    "http://remote.example/"
  ],
  "type": "Create"
}

Activity 9

{
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    {
      "Hashtag": "as:Hashtag",
      "sensitive": "as:sensitive"
    }
  ],
  "actor": "http://actor.example",
  "id": "http://actor.example/activity/kzqz4ptfud4",
  "object": {
    "attributedTo": "http://actor.example",
    "content": "text",
    "id": "http://actor.example/object/QA5x9J3P1Qg",
    "published": "2025-09-09T09:32:39Z",
    "tag": {
      "name": "#\u00fcml\u00e4\u00fct\u00df",
      "type": "Hashtag"
    },
    "to": [
      "https://www.w3.org/ns/activitystreams#Public",
      "http://remote.example/"
    ],
    "type": "Note"
  },
  "published": "2025-09-09T09:32:39Z",
  "to": [
    "https://www.w3.org/ns/activitystreams#Public",
    "http://remote.example/"
  ],
  "type": "Create"
}

Activity 10

{
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    {
      "Hashtag": "as:Hashtag",
      "sensitive": "as:sensitive"
    }
  ],
  "actor": "http://actor.example",
  "id": "http://actor.example/activity/8SaDLfWhJzw",
  "object": {
    "attributedTo": "http://actor.example",
    "content": "text",
    "id": "http://actor.example/object/MuyyFG82IW4",
    "published": "2025-09-09T09:32:39Z",
    "tag": {
      "name": "#\ud83d\udc04",
      "type": "Hashtag"
    },
    "to": [
      "https://www.w3.org/ns/activitystreams#Public",
      "http://remote.example/"
    ],
    "type": "Note"
  },
  "published": "2025-09-09T09:32:39Z",
  "to": [
    "https://www.w3.org/ns/activitystreams#Public",
    "http://remote.example/"
  ],
  "type": "Create"
}

Activity 11

{
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    {
      "Hashtag": "as:Hashtag",
      "sensitive": "as:sensitive"
    }
  ],
  "actor": "http://actor.example",
  "id": "http://actor.example/activity/RLhOWrleINU",
  "object": {
    "attributedTo": "http://actor.example",
    "content": "text",
    "id": "http://actor.example/object/84F4mkX8uuk",
    "published": "2025-09-09T09:32:39Z",
    "tag": {
      "name": "#\u2764\ufe0f",
      "type": "Hashtag"
    },
    "to": [
      "https://www.w3.org/ns/activitystreams#Public",
      "http://remote.example/"
    ],
    "type": "Note"
  },
  "published": "2025-09-09T09:32:39Z",
  "to": [
    "https://www.w3.org/ns/activitystreams#Public",
    "http://remote.example/"
  ],
  "type": "Create"
}

Activity 12

{
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    {
      "Hashtag": "as:Hashtag",
      "sensitive": "as:sensitive"
    }
  ],
  "actor": "http://actor.example",
  "id": "http://actor.example/activity/8opmFIW3a_A",
  "object": {
    "attributedTo": "http://actor.example",
    "content": "text",
    "id": "http://actor.example/object/0gxCY0YdbFQ",
    "published": "2025-09-09T09:32:39Z",
    "tag": {
      "name": "#\u725b",
      "type": "Hashtag"
    },
    "to": [
      "https://www.w3.org/ns/activitystreams#Public",
      "http://remote.example/"
    ],
    "type": "Note"
  },
  "published": "2025-09-09T09:32:39Z",
  "to": [
    "https://www.w3.org/ns/activitystreams#Public",
    "http://remote.example/"
  ],
  "type": "Create"
}

Activity 13

{
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    {
      "Hashtag": "as:Hashtag",
      "sensitive": "as:sensitive"
    }
  ],
  "actor": "http://actor.example",
  "id": "http://actor.example/activity/ngfYTMiLil8",
  "object": {
    "attributedTo": "http://actor.example",
    "content": "broken url parameter",
    "id": "http://actor.example/object/JwezHrMcCHA",
    "published": "2025-09-09T09:32:39Z",
    "tag": {
      "name": "#test",
      "type": "Hashtag",
      "url": "https://ignore.example"
    },
    "to": [
      "https://www.w3.org/ns/activitystreams#Public",
      "http://remote.example/"
    ],
    "type": "Note"
  },
  "published": "2025-09-09T09:32:39Z",
  "to": [
    "https://www.w3.org/ns/activitystreams#Public",
    "http://remote.example/"
  ],
  "type": "Create"
}