diff --git a/lib/federation/activity_pub/types/comments.ex b/lib/federation/activity_pub/types/comments.ex
index 345d7d7e..2fedb789 100644
--- a/lib/federation/activity_pub/types/comments.ex
+++ b/lib/federation/activity_pub/types/comments.ex
@@ -10,6 +10,7 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Comments do
   alias Mobilizon.Federation.ActivityStream.Convertible
   alias Mobilizon.GraphQL.API.Utils, as: APIUtils
   alias Mobilizon.Service.Activity.Comment, as: CommentActivity
+  alias Mobilizon.Service.LanguageDetection
   alias Mobilizon.Share
   alias Mobilizon.Tombstone
   alias Mobilizon.Web.Endpoint
@@ -127,6 +128,7 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Comments do
            ),
          tags <- ConverterUtils.fetch_tags(tags),
          mentions <- Map.get(args, :mentions, []) ++ ConverterUtils.fetch_mentions(mentions),
+         lang <- Map.get(args, :language, "und"),
          args <-
            Map.merge(args, %{
              actor_id: Map.get(args, :actor_id),
@@ -141,7 +143,8 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Comments do
                if(is_nil(in_reply_to_comment),
                  do: nil,
                  else: Comment.get_thread_id(in_reply_to_comment)
-               )
+               ),
+             language: if(lang == "und", do: LanguageDetection.detect(:comment, args), else: lang)
            }) do
       args
     end
diff --git a/lib/federation/activity_pub/types/events.ex b/lib/federation/activity_pub/types/events.ex
index 11ca1f6f..221c1e88 100644
--- a/lib/federation/activity_pub/types/events.ex
+++ b/lib/federation/activity_pub/types/events.ex
@@ -12,6 +12,7 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Events do
   alias Mobilizon.GraphQL.API.Utils, as: APIUtils
   alias Mobilizon.Service.Activity.Event, as: EventActivity
   alias Mobilizon.Service.Formatter.HTML
+  alias Mobilizon.Service.LanguageDetection
   alias Mobilizon.Service.Notifications.Scheduler
   alias Mobilizon.Share
   alias Mobilizon.Tombstone
@@ -234,6 +235,10 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Events do
 
     args
     |> Map.put(:options, options)
+    |> Map.put_new(:language, "und")
+    |> Map.update!(:language, fn lang ->
+      if lang == "und", do: LanguageDetection.detect(:event, args), else: lang
+    end)
     |> Map.update(:tags, [], &ConverterUtils.fetch_tags/1)
     |> Map.update(:contacts, [], &ConverterUtils.fetch_actors/1)
   end
diff --git a/lib/federation/activity_pub/types/posts.ex b/lib/federation/activity_pub/types/posts.ex
index c6a5bab3..279a8ba5 100644
--- a/lib/federation/activity_pub/types/posts.ex
+++ b/lib/federation/activity_pub/types/posts.ex
@@ -8,6 +8,7 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Posts do
   alias Mobilizon.Federation.ActivityStream.Convertible
   alias Mobilizon.Posts.Post
   alias Mobilizon.Service.Activity.Post, as: PostsActivity
+  alias Mobilizon.Service.LanguageDetection
   require Logger
   import Mobilizon.Federation.ActivityPub.Utils, only: [make_create_data: 2, make_update_data: 2]
 
@@ -17,7 +18,7 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Posts do
 
   @impl Entity
   def create(args, additional) do
-    with args <- Map.update(args, :tags, [], &ConverterUtils.fetch_tags/1),
+    with args <- prepare_args(args),
          {:ok, %Post{attributed_to_id: group_id, author_id: creator_id} = post} <-
            Posts.create_post(args),
          {:ok, _} <- PostsActivity.insert_activity(post, subject: "post_created"),
@@ -37,7 +38,7 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Posts do
 
   @impl Entity
   def update(%Post{} = post, args, additional) do
-    with args <- Map.update(args, :tags, [], &ConverterUtils.fetch_tags/1),
+    with args <- prepare_args(args),
          {:ok, %Post{attributed_to_id: group_id, author_id: creator_id} = post} <-
            Posts.update_post(post, args),
          {:ok, _} <- PostsActivity.insert_activity(post, subject: "post_updated"),
@@ -99,4 +100,13 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Posts do
       delete: :moderator
     }
   end
+
+  defp prepare_args(args) do
+    args
+    |> Map.update(:tags, [], &ConverterUtils.fetch_tags/1)
+    |> Map.put_new(:language, "und")
+    |> Map.update!(:language, fn lang ->
+      if lang == "und", do: LanguageDetection.detect(:post, args), else: lang
+    end)
+  end
 end
diff --git a/lib/federation/activity_pub/utils.ex b/lib/federation/activity_pub/utils.ex
index 86252e25..7282be86 100644
--- a/lib/federation/activity_pub/utils.ex
+++ b/lib/federation/activity_pub/utils.ex
@@ -36,6 +36,7 @@ defmodule Mobilizon.Federation.ActivityPub.Utils do
         "https://www.w3.org/ns/activitystreams",
         "https://litepub.social/context.jsonld",
         %{
+          "@language" => "und",
           "sc" => "http://schema.org#",
           "ical" => "http://www.w3.org/2002/12/cal/ical#",
           "pt" => "https://joinpeertube.org/ns#",
@@ -91,7 +92,8 @@ defmodule Mobilizon.Federation.ActivityPub.Utils do
           },
           "PropertyValue" => "sc:PropertyValue",
           "value" => "sc:value",
-          "propertyID" => "sc:propertyID"
+          "propertyID" => "sc:propertyID",
+          "inLanguage" => "sc:inLanguage"
         }
       ]
     }
diff --git a/lib/federation/activity_stream/converter/event.ex b/lib/federation/activity_stream/converter/event.ex
index e5ff9574..65825a32 100644
--- a/lib/federation/activity_stream/converter/event.ex
+++ b/lib/federation/activity_stream/converter/event.ex
@@ -83,7 +83,8 @@ defmodule Mobilizon.Federation.ActivityStream.Converter.Event do
         mentions: mentions,
         physical_address_id: address_id,
         updated_at: object["updated"],
-        publish_at: object["published"]
+        publish_at: object["published"],
+        language: object["inLanguage"]
       }
     else
       {:ok, %Actor{suspended: true}} ->
@@ -128,7 +129,8 @@ defmodule Mobilizon.Federation.ActivityStream.Converter.Event do
       "draft" => event.draft,
       "ical:status" => event.status |> to_string |> String.upcase(),
       "id" => event.url,
-      "url" => event.url
+      "url" => event.url,
+      "inLanguage" => event.language
     }
     |> maybe_add_physical_address(event)
     |> maybe_add_event_picture(event)
diff --git a/lib/graphql/schema/discussions/comment.ex b/lib/graphql/schema/discussions/comment.ex
index cef5f555..21c664c0 100644
--- a/lib/graphql/schema/discussions/comment.ex
+++ b/lib/graphql/schema/discussions/comment.ex
@@ -54,6 +54,8 @@ defmodule Mobilizon.GraphQL.Schema.Discussions.CommentType do
     field(:is_announcement, non_null(:boolean),
       description: "Whether this comment needs to be announced to participants"
     )
+
+    field(:language, non_null(:string), description: "The comment language")
   end
 
   @desc "The list of visibility options for a comment"
@@ -89,6 +91,7 @@ defmodule Mobilizon.GraphQL.Schema.Discussions.CommentType do
       arg(:text, non_null(:string), description: "The comment's body")
       arg(:event_id, non_null(:id), description: "The event under which this comment is")
       arg(:in_reply_to_comment_id, :id, description: "The comment ID this one replies to")
+      arg(:language, :string, description: "The comment language", default_value: "und")
 
       arg(:is_announcement, :boolean, description: "Should this comment be announced to everyone?")
 
@@ -99,6 +102,7 @@ defmodule Mobilizon.GraphQL.Schema.Discussions.CommentType do
     field :update_comment, type: :comment do
       arg(:text, non_null(:string), description: "The comment updated body")
       arg(:comment_id, non_null(:id), description: "The comment ID")
+      arg(:language, :string, description: "The comment language", default_value: "und")
 
       arg(:is_announcement, :boolean, description: "Should this comment be announced to everyone?")
 
diff --git a/lib/graphql/schema/event.ex b/lib/graphql/schema/event.ex
index e3eb688a..2bfe5993 100644
--- a/lib/graphql/schema/event.ex
+++ b/lib/graphql/schema/event.ex
@@ -104,6 +104,7 @@ defmodule Mobilizon.GraphQL.Schema.EventType do
     field(:inserted_at, :datetime, description: "When the event was created")
     field(:options, :event_options, description: "The event options")
     field(:metadata, list_of(:event_metadata), description: "A key-value list of metadata")
+    field(:language, non_null(:string), description: "The event language")
   end
 
   @desc "The list of visibility options for an event"
@@ -401,6 +402,7 @@ defmodule Mobilizon.GraphQL.Schema.EventType do
       )
 
       arg(:contacts, list_of(:contact), default_value: [], description: "The events contacts")
+      arg(:language, :string, description: "The event language", default_value: "und")
 
       resolve(&Event.create_event/3)
     end
@@ -444,6 +446,7 @@ defmodule Mobilizon.GraphQL.Schema.EventType do
       arg(:metadata, list_of(:event_metadata_input), description: "The event metadata")
       arg(:draft, :boolean, description: "Whether or not the event is a draft")
       arg(:contacts, list_of(:contact), default_value: [], description: "The events contacts")
+      arg(:language, :string, description: "The event language", default_value: "und")
 
       resolve(&Event.update_event/3)
     end
diff --git a/lib/graphql/schema/post.ex b/lib/graphql/schema/post.ex
index 8c0d6203..6f65c5de 100644
--- a/lib/graphql/schema/post.ex
+++ b/lib/graphql/schema/post.ex
@@ -20,6 +20,7 @@ defmodule Mobilizon.GraphQL.Schema.PostType do
     field(:publish_at, :datetime, description: "When the post was published")
     field(:inserted_at, :datetime, description: "The post's creation date")
     field(:updated_at, :datetime, description: "The post's last update date")
+    field(:language, non_null(:string), description: "The post language")
 
     field(:tags, list_of(:tag),
       resolve: &Tag.list_tags_for_post/3,
@@ -71,6 +72,7 @@ defmodule Mobilizon.GraphQL.Schema.PostType do
       arg(:draft, :boolean, default_value: false, description: "Whether the post is a draft")
       arg(:visibility, :post_visibility, description: "The post's visibility")
       arg(:publish_at, :datetime, description: "The post's publish date")
+      arg(:language, :string, description: "The post language", default_value: "und")
 
       arg(:tags, list_of(:string),
         default_value: [],
@@ -93,6 +95,7 @@ defmodule Mobilizon.GraphQL.Schema.PostType do
       arg(:attributed_to_id, :id, description: "The group the post is attributed to")
       arg(:draft, :boolean, description: "Whether the post is a draft")
       arg(:visibility, :post_visibility, description: "The post's visibility")
+      arg(:language, :string, description: "The post language", default_value: "und")
 
       arg(:publish_at, :datetime,
         description: "The time when the posts is going to be or has been published"
diff --git a/lib/mobilizon/discussions/comment.ex b/lib/mobilizon/discussions/comment.ex
index bba59586..3141e4ae 100644
--- a/lib/mobilizon/discussions/comment.ex
+++ b/lib/mobilizon/discussions/comment.ex
@@ -30,7 +30,8 @@ defmodule Mobilizon.Discussions.Comment do
           mentions: [Mention.t()],
           media: [Media.t()],
           in_reply_to_comment: t,
-          origin_comment: t
+          origin_comment: t,
+          language: String.t()
         }
 
   # When deleting an event we only nihilify everything
@@ -46,7 +47,8 @@ defmodule Mobilizon.Discussions.Comment do
     :deleted_at,
     :local,
     :is_announcement,
-    :discussion_id
+    :discussion_id,
+    :language
   ]
   @attrs @required_attrs ++ @optional_attrs
 
@@ -60,6 +62,7 @@ defmodule Mobilizon.Discussions.Comment do
     field(:deleted_at, :utc_datetime)
     field(:published_at, :utc_datetime)
     field(:is_announcement, :boolean, default: false)
+    field(:language, :string, default: "und")
 
     belongs_to(:actor, Actor, foreign_key: :actor_id)
     belongs_to(:attributed_to, Actor, foreign_key: :attributed_to_id)
diff --git a/lib/mobilizon/events/event.ex b/lib/mobilizon/events/event.ex
index d024cc7c..b4a46d7b 100644
--- a/lib/mobilizon/events/event.ex
+++ b/lib/mobilizon/events/event.ex
@@ -62,7 +62,8 @@ defmodule Mobilizon.Events.Event do
           mentions: [Mention.t()],
           tags: [Tag.t()],
           participants: [Actor.t()],
-          contacts: [Actor.t()]
+          contacts: [Actor.t()],
+          language: String.t()
         }
 
   @update_required_attrs [:title, :begins_on, :organizer_actor_id]
@@ -83,7 +84,8 @@ defmodule Mobilizon.Events.Event do
     :phone_address,
     :picture_id,
     :physical_address_id,
-    :attributed_to_id
+    :attributed_to_id,
+    :language
   ]
   @attrs @required_attrs ++ @optional_attrs
 
@@ -106,6 +108,7 @@ defmodule Mobilizon.Events.Event do
     field(:online_address, :string)
     field(:phone_address, :string)
     field(:category, :string)
+    field(:language, :string, default: "und")
 
     embeds_one(:options, EventOptions, on_replace: :delete)
     embeds_one(:participant_stats, EventParticipantStats, on_replace: :update)
@@ -170,7 +173,6 @@ defmodule Mobilizon.Events.Event do
     |> validate_length(:online_address, min: 3, max: 2000)
     |> validate_length(:phone_address, min: 3, max: 200)
     |> validate_length(:category, min: 2, max: 100)
-    # |> validate_length(:category, min: 2, max: 100)
     |> validate_length(:slug, min: 3, max: 200)
   end
 
diff --git a/lib/mobilizon/posts/post.ex b/lib/mobilizon/posts/post.ex
index a2028ccd..cb40587b 100644
--- a/lib/mobilizon/posts/post.ex
+++ b/lib/mobilizon/posts/post.ex
@@ -43,7 +43,8 @@ defmodule Mobilizon.Posts.Post do
           attributed_to: Actor.t(),
           picture: Media.t(),
           media: [Media.t()],
-          tags: [Tag.t()]
+          tags: [Tag.t()],
+          language: String.t()
         }
 
   @primary_key {:id, Ecto.UUID, autogenerate: true}
@@ -57,6 +58,7 @@ defmodule Mobilizon.Posts.Post do
     field(:url, :string)
     field(:publish_at, :utc_datetime)
     field(:visibility, PostVisibility, default: :public)
+    field(:language, :string, default: "und")
     belongs_to(:author, Actor)
     belongs_to(:attributed_to, Actor)
     belongs_to(:picture, Media, on_replace: :update)
@@ -76,7 +78,7 @@ defmodule Mobilizon.Posts.Post do
     :author_id,
     :attributed_to_id
   ]
-  @optional_attrs [:picture_id, :local, :publish_at, :visibility]
+  @optional_attrs [:picture_id, :local, :publish_at, :visibility, :language]
   @attrs @required_attrs ++ @optional_attrs
 
   @doc false
diff --git a/lib/service/language_detection/language_detection.ex b/lib/service/language_detection/language_detection.ex
new file mode 100644
index 00000000..96d50d49
--- /dev/null
+++ b/lib/service/language_detection/language_detection.ex
@@ -0,0 +1,84 @@
+defmodule Mobilizon.Service.LanguageDetection do
+  @moduledoc """
+  Detect the language of the event
+  """
+  alias Mobilizon.Service.Formatter.HTML
+
+  @und "und"
+
+  @paasaa_languages Paasaa.Data.languages()
+                    |> Map.values()
+                    |> List.flatten()
+                    |> Enum.map(fn {lang, _val} ->
+                      lang
+                    end)
+
+  @allow_listed_locales Mobilizon.Cldr.known_locale_names()
+
+  @type entity_type :: :event | :comment | :post
+
+  @spec detect(entity_type(), map()) :: String.t()
+  def detect(:event, %{title: title} = args) do
+    description = Map.get(args, :description)
+
+    if is_nil(description) or description == "" do
+      title
+      |> Paasaa.detect(whitelist: allow_listed_languages())
+      |> normalize()
+    else
+      sanitized_description = HTML.strip_tags_and_insert_spaces(description)
+
+      "#{title}\n\n#{sanitized_description}"
+      |> Paasaa.detect(whitelist: allow_listed_languages())
+      |> normalize()
+    end
+  end
+
+  def detect(:comment, %{text: text}) do
+    text
+    |> HTML.strip_tags_and_insert_spaces()
+    |> Paasaa.detect(whitelist: allow_listed_languages())
+    |> normalize()
+  end
+
+  def detect(:post, %{title: title} = args) do
+    body = Map.get(args, :body)
+
+    if is_nil(body) or body == "" do
+      title
+      |> Paasaa.detect(whitelist: allow_listed_languages())
+      |> normalize()
+    else
+      sanitized_body = HTML.strip_tags_and_insert_spaces(body)
+
+      "#{title}\n\n#{sanitized_body}"
+      |> Paasaa.detect(whitelist: allow_listed_languages())
+      |> normalize()
+    end
+  end
+
+  def detect(_, _), do: @und
+
+  @spec normalize(String.t()) :: String.t()
+  def normalize(""), do: @und
+
+  def normalize(language) do
+    case Cldr.AcceptLanguage.parse(language, Mobilizon.Cldr) do
+      {:ok, [{_, tag}]} ->
+        tag.language
+
+      _ ->
+        @und
+    end
+  end
+
+  def allow_listed_languages do
+    @paasaa_languages
+    |> Enum.map(fn lang ->
+      {__MODULE__.normalize(lang), lang}
+    end)
+    |> Enum.into(%{})
+    |> Map.take(@allow_listed_locales)
+    |> Map.values()
+  end
+end
diff --git a/mix.exs b/mix.exs
index 88948be4..32c23b9f 100644
--- a/mix.exs
+++ b/mix.exs
@@ -165,6 +165,7 @@ defmodule Mobilizon.Mixfile do
        ref: "4361bd02b0b7f2cb5f8ac302bcd1210b57964a51"},
       {:eblurhash, "~> 1.2"},
       {:struct_access, "~> 1.1.2"},
+      {:paasaa, "~> 0.5.0"},
       # Dev and test dependencies
       {:phoenix_live_reload, "~> 1.2", only: [:dev, :e2e]},
       {:ex_machina, "~> 2.3", only: [:dev, :test]},
diff --git a/mix.lock b/mix.lock
index 63d99747..e5238d2a 100644
--- a/mix.lock
+++ b/mix.lock
@@ -100,6 +100,7 @@
   "oauth2": {:hex, :oauth2, "2.0.0", "338382079fe16c514420fa218b0903f8ad2d4bfc0ad0c9f988867dfa246731b0", [:mix], [{:hackney, "~> 1.13", [hex: :hackney, repo: "hexpm", optional: false]}], "hexpm", "881b8364ac7385f9fddc7949379cbe3f7081da37233a1aa7aab844670a91e7e7"},
   "oauther": {:hex, :oauther, "1.1.1", "7d8b16167bb587ecbcddd3f8792beb9ec3e7b65c1f8ebd86b8dd25318d535752", [:mix], [], "hexpm", "9374f4302045321874cccdc57eb975893643bd69c3b22bf1312dab5f06e5788e"},
   "oban": {:hex, :oban, "2.8.0", "e44b19a30e30bb983099f55d59749316ff0eaf5dfef4214e1190738176653e50", [:mix], [{:ecto_sql, ">= 3.4.3", [hex: :ecto_sql, repo: "hexpm", optional: false]}, {:jason, "~> 1.1", [hex: :jason, repo: "hexpm", optional: false]}, {:postgrex, "~> 0.14", [hex: :postgrex, repo: "hexpm", optional: false]}, {:telemetry, "~> 0.4", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "2954a2ac418f7cc4217c0772a3dd3a70e2966240583b97f4126a489e1300a573"},
+  "paasaa": {:hex, :paasaa, "0.5.1", "58d8bf61902adfd1d04815a115f0eb3b996845c0360f1831854e21073411e822", [:mix], [], "hexpm", "571f1a33b8e184396a93fc18ee5331f2655c96ba9a6fc383dc675e4bc8fc7596"},
   "parse_trans": {:hex, :parse_trans, "3.3.1", "16328ab840cc09919bd10dab29e431da3af9e9e7e7e6f0089dd5a2d2820011d8", [:rebar3], [], "hexpm", "07cd9577885f56362d414e8c4c4e6bdf10d43a8767abb92d24cbe8b24c54888b"},
   "phoenix": {:hex, :phoenix, "1.5.10", "3ee7d5c17ff9626d72d374d8fc8909bf00f4323fd15549fbe3abbbd38b5299c8", [:mix], [{:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: true]}, {:phoenix_html, "~> 2.13 or ~> 3.0", [hex: :phoenix_html, repo: "hexpm", optional: true]}, {:phoenix_pubsub, "~> 2.0", [hex: :phoenix_pubsub, repo: "hexpm", optional: false]}, {:plug, "~> 1.10", [hex: :plug, repo: "hexpm", optional: false]}, {:plug_cowboy, "~> 1.0 or ~> 2.2", [hex: :plug_cowboy, repo: "hexpm", optional: true]}, {:plug_crypto, "~> 1.1.2 or ~> 1.2", [hex: :plug_crypto, repo: "hexpm", optional: false]}, {:telemetry, "~> 0.4", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "f9c2eaa5a8fe5a412610c6aa84ccdb6f3e92f333d4df7fbaeb0d5a157dbfb48d"},
   "phoenix_ecto": {:hex, :phoenix_ecto, "4.4.0", "0672ed4e4808b3fbed494dded89958e22fb882de47a97634c0b13e7b0b5f7720", [:mix], [{:ecto, "~> 3.3", [hex: :ecto, repo: "hexpm", optional: false]}, {:phoenix_html, "~> 2.14.2 or ~> 3.0", [hex: :phoenix_html, repo: "hexpm", optional: true]}, {:plug, "~> 1.9", [hex: :plug, repo: "hexpm", optional: false]}], "hexpm", "09864e558ed31ee00bd48fcc1d4fc58ae9678c9e81649075431e69dbabb43cc1"},
diff --git a/priv/repo/migrations/20210819161507_add_language_to_entities.exs b/priv/repo/migrations/20210819161507_add_language_to_entities.exs
new file mode 100644
index 00000000..6cc5909d
--- /dev/null
+++ b/priv/repo/migrations/20210819161507_add_language_to_entities.exs
@@ -0,0 +1,17 @@
+defmodule Mobilizon.Storage.Repo.Migrations.AddLanguageToEntities do
+  use Ecto.Migration
+
+  def change do
+    alter table(:events) do
+      add(:language, :string, default: "und")
+    end
+
+    alter table(:comments) do
+      add(:language, :string, default: "und")
+    end
+
+    alter table(:posts) do
+      add(:language, :string, default: "und")
+    end
+  end
+end
diff --git a/test/graphql/resolvers/event_test.exs b/test/graphql/resolvers/event_test.exs
index 4505236a..1d8423c6 100644
--- a/test/graphql/resolvers/event_test.exs
+++ b/test/graphql/resolvers/event_test.exs
@@ -84,7 +84,8 @@ defmodule Mobilizon.Web.Resolvers.EventTest do
       $attributed_to_id: ID,
       $online_address: String,
       $options: EventOptionsInput,
-      $draft: Boolean
+      $draft: Boolean,
+      $language: String
       ) {
       createEvent(
           title: $title,
@@ -97,7 +98,8 @@ defmodule Mobilizon.Web.Resolvers.EventTest do
           attributed_to_id: $attributed_to_id,
           online_address: $online_address,
           options: $options,
-          draft: $draft
+          draft: $draft,
+          language: $language
       ) {
         id,
         uuid,
@@ -113,7 +115,8 @@ defmodule Mobilizon.Web.Resolvers.EventTest do
         online_address,
         phone_address,
         category,
-        draft,
+        draft
+        language
         options {
           maximumAttendeeCapacity,
           showRemainingAttendeeCapacity,
@@ -636,6 +639,51 @@ defmodule Mobilizon.Web.Resolvers.EventTest do
 
       assert json_response(res, 200)["data"]["createEvent"]["picture"]["url"]
     end
+
+    test "create_event/3 creates an event with detected language", %{
+      conn: conn,
+      actor: %Actor{id: actor_id},
+      user: user
+    } do
+      res =
+        conn
+        |> auth_conn(user)
+        |> AbsintheHelpers.graphql_query(
+          query: @create_event_mutation,
+          variables: %{
+            title: "Come to my event",
+            description: "This should be long enough to get detected",
+            organizer_actor_id: actor_id,
+            begins_on: "2021-07-26T09:00:00Z"
+          }
+        )
+
+      assert res["errors"] == nil
+      assert res["data"]["createEvent"]["language"] == "en"
+    end
+
+    test "create_event/3 creates an event with manually set language", %{
+      conn: conn,
+      actor: %Actor{id: actor_id},
+      user: user
+    } do
+      res =
+        conn
+        |> auth_conn(user)
+        |> AbsintheHelpers.graphql_query(
+          query: @create_event_mutation,
+          variables: %{
+            title: "Come to my event",
+            description: "This should be long enough to get detected",
+            organizer_actor_id: actor_id,
+            begins_on: "2021-07-26T09:00:00Z",
+            language: "it"
+          }
+        )
+
+      assert res["errors"] == nil
+      assert res["data"]["createEvent"]["language"] == "it"
+    end
   end
 
   describe "create_event/3 on behalf of a group" do