diff --git a/app/controllers/api/base_controller.rb b/app/controllers/api/base_controller.rb
index 21a79f8926..56bf69c402 100644
--- a/app/controllers/api/base_controller.rb
+++ b/app/controllers/api/base_controller.rb
@@ -6,6 +6,7 @@ class Api::BaseController < ApplicationController
 
   include RateLimitHeaders
   include AccessTokenTrackingConcern
+  include ApiCachingConcern
 
   skip_before_action :store_current_location
   skip_before_action :require_functional!, unless: :whitelist_mode?
@@ -13,6 +14,8 @@ class Api::BaseController < ApplicationController
   before_action :require_authenticated_user!, if: :disallow_unauthenticated_api_access?
   before_action :require_not_suspended!
 
+  vary_by 'Authorization'
+
   protect_from_forgery with: :null_session
 
   content_security_policy do |p|
diff --git a/app/controllers/api/v1/accounts/follower_accounts_controller.rb b/app/controllers/api/v1/accounts/follower_accounts_controller.rb
index 68952de893..1a996d362a 100644
--- a/app/controllers/api/v1/accounts/follower_accounts_controller.rb
+++ b/app/controllers/api/v1/accounts/follower_accounts_controller.rb
@@ -6,6 +6,7 @@ class Api::V1::Accounts::FollowerAccountsController < Api::BaseController
   after_action :insert_pagination_headers
 
   def index
+    cache_if_unauthenticated!
     @accounts = load_accounts
     render json: @accounts, each_serializer: REST::AccountSerializer
   end
diff --git a/app/controllers/api/v1/accounts/following_accounts_controller.rb b/app/controllers/api/v1/accounts/following_accounts_controller.rb
index 0a4d2ae7b3..6e6ebae43b 100644
--- a/app/controllers/api/v1/accounts/following_accounts_controller.rb
+++ b/app/controllers/api/v1/accounts/following_accounts_controller.rb
@@ -6,6 +6,7 @@ class Api::V1::Accounts::FollowingAccountsController < Api::BaseController
   after_action :insert_pagination_headers
 
   def index
+    cache_if_unauthenticated!
     @accounts = load_accounts
     render json: @accounts, each_serializer: REST::AccountSerializer
   end
diff --git a/app/controllers/api/v1/accounts/lookup_controller.rb b/app/controllers/api/v1/accounts/lookup_controller.rb
index 8597f891d6..6d63398781 100644
--- a/app/controllers/api/v1/accounts/lookup_controller.rb
+++ b/app/controllers/api/v1/accounts/lookup_controller.rb
@@ -5,6 +5,7 @@ class Api::V1::Accounts::LookupController < Api::BaseController
   before_action :set_account
 
   def show
+    cache_if_unauthenticated!
     render json: @account, serializer: REST::AccountSerializer
   end
 
diff --git a/app/controllers/api/v1/accounts/statuses_controller.rb b/app/controllers/api/v1/accounts/statuses_controller.rb
index 7ed48cf658..51f541bd23 100644
--- a/app/controllers/api/v1/accounts/statuses_controller.rb
+++ b/app/controllers/api/v1/accounts/statuses_controller.rb
@@ -7,6 +7,7 @@ class Api::V1::Accounts::StatusesController < Api::BaseController
   after_action :insert_pagination_headers, unless: -> { truthy_param?(:pinned) }
 
   def index
+    cache_if_unauthenticated!
     @statuses = load_statuses
     render json: @statuses, each_serializer: REST::StatusSerializer, relationships: StatusRelationshipsPresenter.new(@statuses, current_user&.account_id)
   end
diff --git a/app/controllers/api/v1/accounts_controller.rb b/app/controllers/api/v1/accounts_controller.rb
index 7dff66efac..8af4242ba3 100644
--- a/app/controllers/api/v1/accounts_controller.rb
+++ b/app/controllers/api/v1/accounts_controller.rb
@@ -18,6 +18,7 @@ class Api::V1::AccountsController < Api::BaseController
   override_rate_limit_headers :follow, family: :follows
 
   def show
+    cache_if_unauthenticated!
     render json: @account, serializer: REST::AccountSerializer
   end
 
diff --git a/app/controllers/api/v1/custom_emojis_controller.rb b/app/controllers/api/v1/custom_emojis_controller.rb
index 380dbe8bf3..d4e7c43cb0 100644
--- a/app/controllers/api/v1/custom_emojis_controller.rb
+++ b/app/controllers/api/v1/custom_emojis_controller.rb
@@ -1,8 +1,10 @@
 # frozen_string_literal: true
 
 class Api::V1::CustomEmojisController < Api::BaseController
+  vary_by ''
+
   def index
-    expires_in 3.minutes, public: true
+    cache_even_if_authenticated!
     render_with_cache(each_serializer: REST::CustomEmojiSerializer) { CustomEmoji.listed.includes(:category) }
   end
 end
diff --git a/app/controllers/api/v1/directories_controller.rb b/app/controllers/api/v1/directories_controller.rb
index c91543e3a3..c0585e8599 100644
--- a/app/controllers/api/v1/directories_controller.rb
+++ b/app/controllers/api/v1/directories_controller.rb
@@ -5,6 +5,7 @@ class Api::V1::DirectoriesController < Api::BaseController
   before_action :set_accounts
 
   def show
+    cache_if_unauthenticated!
     render json: @accounts, each_serializer: REST::AccountSerializer
   end
 
diff --git a/app/controllers/api/v1/instances/activity_controller.rb b/app/controllers/api/v1/instances/activity_controller.rb
index 7ccfec7036..3d55d990af 100644
--- a/app/controllers/api/v1/instances/activity_controller.rb
+++ b/app/controllers/api/v1/instances/activity_controller.rb
@@ -5,8 +5,10 @@ class Api::V1::Instances::ActivityController < Api::BaseController
 
   skip_before_action :require_authenticated_user!, unless: :whitelist_mode?
 
+  vary_by ''
+
   def show
-    expires_in 1.day, public: true
+    cache_even_if_authenticated!
     render_with_cache json: :activity, expires_in: 1.day
   end
 
diff --git a/app/controllers/api/v1/instances/domain_blocks_controller.rb b/app/controllers/api/v1/instances/domain_blocks_controller.rb
index 37a6906fb6..49fd8fa987 100644
--- a/app/controllers/api/v1/instances/domain_blocks_controller.rb
+++ b/app/controllers/api/v1/instances/domain_blocks_controller.rb
@@ -6,8 +6,10 @@ class Api::V1::Instances::DomainBlocksController < Api::BaseController
   before_action :require_enabled_api!
   before_action :set_domain_blocks
 
+  vary_by ''
+
   def index
-    expires_in 3.minutes, public: true
+    cache_even_if_authenticated!
     render json: @domain_blocks, each_serializer: REST::DomainBlockSerializer, with_comment: (Setting.show_domain_blocks_rationale == 'all' || (Setting.show_domain_blocks_rationale == 'users' && user_signed_in?))
   end
 
diff --git a/app/controllers/api/v1/instances/extended_descriptions_controller.rb b/app/controllers/api/v1/instances/extended_descriptions_controller.rb
index c72e16cff2..17cf0d790d 100644
--- a/app/controllers/api/v1/instances/extended_descriptions_controller.rb
+++ b/app/controllers/api/v1/instances/extended_descriptions_controller.rb
@@ -5,8 +5,10 @@ class Api::V1::Instances::ExtendedDescriptionsController < Api::BaseController
 
   before_action :set_extended_description
 
+  vary_by ''
+
   def show
-    expires_in 3.minutes, public: true
+    cache_even_if_authenticated!
     render json: @extended_description, serializer: REST::ExtendedDescriptionSerializer
   end
 
diff --git a/app/controllers/api/v1/instances/peers_controller.rb b/app/controllers/api/v1/instances/peers_controller.rb
index b2669a84eb..20809d7553 100644
--- a/app/controllers/api/v1/instances/peers_controller.rb
+++ b/app/controllers/api/v1/instances/peers_controller.rb
@@ -5,8 +5,10 @@ class Api::V1::Instances::PeersController < Api::BaseController
 
   skip_before_action :require_authenticated_user!, unless: :whitelist_mode?
 
+  vary_by ''
+
   def index
-    expires_in 1.day, public: true
+    cache_even_if_authenticated!
     render_with_cache(expires_in: 1.day) { Instance.where.not(domain: DomainBlock.select(:domain)).pluck(:domain) }
   end
 
diff --git a/app/controllers/api/v1/instances/privacy_policies_controller.rb b/app/controllers/api/v1/instances/privacy_policies_controller.rb
index dbd69f54d4..36889f7335 100644
--- a/app/controllers/api/v1/instances/privacy_policies_controller.rb
+++ b/app/controllers/api/v1/instances/privacy_policies_controller.rb
@@ -5,8 +5,10 @@ class Api::V1::Instances::PrivacyPoliciesController < Api::BaseController
 
   before_action :set_privacy_policy
 
+  vary_by ''
+
   def show
-    expires_in 1.day, public: true
+    cache_even_if_authenticated!
     render json: @privacy_policy, serializer: REST::PrivacyPolicySerializer
   end
 
diff --git a/app/controllers/api/v1/instances/rules_controller.rb b/app/controllers/api/v1/instances/rules_controller.rb
index 93cf3c7594..cd5cc7b086 100644
--- a/app/controllers/api/v1/instances/rules_controller.rb
+++ b/app/controllers/api/v1/instances/rules_controller.rb
@@ -5,7 +5,10 @@ class Api::V1::Instances::RulesController < Api::BaseController
 
   before_action :set_rules
 
+  vary_by ''
+
   def index
+    cache_even_if_authenticated!
     render json: @rules, each_serializer: REST::RuleSerializer
   end
 
diff --git a/app/controllers/api/v1/instances/translation_languages_controller.rb b/app/controllers/api/v1/instances/translation_languages_controller.rb
index 3910a499e8..c4680cccb8 100644
--- a/app/controllers/api/v1/instances/translation_languages_controller.rb
+++ b/app/controllers/api/v1/instances/translation_languages_controller.rb
@@ -5,8 +5,10 @@ class Api::V1::Instances::TranslationLanguagesController < Api::BaseController
 
   before_action :set_languages
 
+  vary_by ''
+
   def show
-    expires_in 1.day, public: true
+    cache_even_if_authenticated!
     render json: @languages
   end
 
diff --git a/app/controllers/api/v1/instances_controller.rb b/app/controllers/api/v1/instances_controller.rb
index 3cdb404cb8..d4c822e64a 100644
--- a/app/controllers/api/v1/instances_controller.rb
+++ b/app/controllers/api/v1/instances_controller.rb
@@ -3,8 +3,10 @@
 class Api::V1::InstancesController < Api::BaseController
   skip_before_action :require_authenticated_user!, unless: :whitelist_mode?
 
+  vary_by ''
+
   def show
-    expires_in 3.minutes, public: true
+    cache_even_if_authenticated!
     render_with_cache json: InstancePresenter.new, serializer: REST::V1::InstanceSerializer, root: 'instance'
   end
 end
diff --git a/app/controllers/api/v1/polls_controller.rb b/app/controllers/api/v1/polls_controller.rb
index 6435e9f0dc..ffc70a8496 100644
--- a/app/controllers/api/v1/polls_controller.rb
+++ b/app/controllers/api/v1/polls_controller.rb
@@ -8,6 +8,7 @@ class Api::V1::PollsController < Api::BaseController
   before_action :refresh_poll
 
   def show
+    cache_if_unauthenticated!
     render json: @poll, serializer: REST::PollSerializer, include_results: true
   end
 
diff --git a/app/controllers/api/v1/statuses/favourited_by_accounts_controller.rb b/app/controllers/api/v1/statuses/favourited_by_accounts_controller.rb
index b138fa2650..73eb11e711 100644
--- a/app/controllers/api/v1/statuses/favourited_by_accounts_controller.rb
+++ b/app/controllers/api/v1/statuses/favourited_by_accounts_controller.rb
@@ -8,6 +8,7 @@ class Api::V1::Statuses::FavouritedByAccountsController < Api::BaseController
   after_action :insert_pagination_headers
 
   def index
+    cache_if_unauthenticated!
     @accounts = load_accounts
     render json: @accounts, each_serializer: REST::AccountSerializer
   end
diff --git a/app/controllers/api/v1/statuses/histories_controller.rb b/app/controllers/api/v1/statuses/histories_controller.rb
index 7fe73a6f54..dff2425d06 100644
--- a/app/controllers/api/v1/statuses/histories_controller.rb
+++ b/app/controllers/api/v1/statuses/histories_controller.rb
@@ -7,6 +7,7 @@ class Api::V1::Statuses::HistoriesController < Api::BaseController
   before_action :set_status
 
   def show
+    cache_if_unauthenticated!
     render json: @status.edits.includes(:account, status: [:account]), each_serializer: REST::StatusEditSerializer
   end
 
diff --git a/app/controllers/api/v1/statuses/reblogged_by_accounts_controller.rb b/app/controllers/api/v1/statuses/reblogged_by_accounts_controller.rb
index 4b545f9826..41672e7539 100644
--- a/app/controllers/api/v1/statuses/reblogged_by_accounts_controller.rb
+++ b/app/controllers/api/v1/statuses/reblogged_by_accounts_controller.rb
@@ -8,6 +8,7 @@ class Api::V1::Statuses::RebloggedByAccountsController < Api::BaseController
   after_action :insert_pagination_headers
 
   def index
+    cache_if_unauthenticated!
     @accounts = load_accounts
     render json: @accounts, each_serializer: REST::AccountSerializer
   end
diff --git a/app/controllers/api/v1/statuses_controller.rb b/app/controllers/api/v1/statuses_controller.rb
index fadd1b0451..064e7632a8 100644
--- a/app/controllers/api/v1/statuses_controller.rb
+++ b/app/controllers/api/v1/statuses_controller.rb
@@ -24,11 +24,14 @@ class Api::V1::StatusesController < Api::BaseController
   DESCENDANTS_DEPTH_LIMIT = 20
 
   def show
+    cache_if_unauthenticated!
     @status = cache_collection([@status], Status).first
     render json: @status, serializer: REST::StatusSerializer
   end
 
   def context
+    cache_if_unauthenticated!
+
     ancestors_limit         = CONTEXT_LIMIT
     descendants_limit       = CONTEXT_LIMIT
     descendants_depth_limit = nil
diff --git a/app/controllers/api/v1/tags_controller.rb b/app/controllers/api/v1/tags_controller.rb
index a08fd21877..284ec85937 100644
--- a/app/controllers/api/v1/tags_controller.rb
+++ b/app/controllers/api/v1/tags_controller.rb
@@ -8,6 +8,7 @@ class Api::V1::TagsController < Api::BaseController
   override_rate_limit_headers :follow, family: :follows
 
   def show
+    cache_if_unauthenticated!
     render json: @tag, serializer: REST::TagSerializer
   end
 
diff --git a/app/controllers/api/v1/timelines/public_controller.rb b/app/controllers/api/v1/timelines/public_controller.rb
index d253b744f9..5bbd92b9ee 100644
--- a/app/controllers/api/v1/timelines/public_controller.rb
+++ b/app/controllers/api/v1/timelines/public_controller.rb
@@ -5,6 +5,7 @@ class Api::V1::Timelines::PublicController < Api::BaseController
   after_action :insert_pagination_headers, unless: -> { @statuses.empty? }
 
   def show
+    cache_if_unauthenticated!
     @statuses = load_statuses
     render json: @statuses, each_serializer: REST::StatusSerializer, relationships: StatusRelationshipsPresenter.new(@statuses, current_user&.account_id)
   end
diff --git a/app/controllers/api/v1/timelines/tag_controller.rb b/app/controllers/api/v1/timelines/tag_controller.rb
index 64a1db58df..9cd7b99046 100644
--- a/app/controllers/api/v1/timelines/tag_controller.rb
+++ b/app/controllers/api/v1/timelines/tag_controller.rb
@@ -5,6 +5,7 @@ class Api::V1::Timelines::TagController < Api::BaseController
   after_action :insert_pagination_headers, unless: -> { @statuses.empty? }
 
   def show
+    cache_if_unauthenticated!
     @statuses = load_statuses
     render json: @statuses, each_serializer: REST::StatusSerializer, relationships: StatusRelationshipsPresenter.new(@statuses, current_user&.account_id)
   end
diff --git a/app/controllers/api/v1/trends/links_controller.rb b/app/controllers/api/v1/trends/links_controller.rb
index 3ce20fb786..57cfa0b7e4 100644
--- a/app/controllers/api/v1/trends/links_controller.rb
+++ b/app/controllers/api/v1/trends/links_controller.rb
@@ -1,6 +1,8 @@
 # frozen_string_literal: true
 
 class Api::V1::Trends::LinksController < Api::BaseController
+  vary_by 'Authorization, Accept-Language'
+
   before_action :set_links
 
   after_action :insert_pagination_headers
@@ -8,6 +10,7 @@ class Api::V1::Trends::LinksController < Api::BaseController
   DEFAULT_LINKS_LIMIT = 10
 
   def index
+    cache_if_unauthenticated!
     render json: @links, each_serializer: REST::Trends::LinkSerializer
   end
 
diff --git a/app/controllers/api/v1/trends/statuses_controller.rb b/app/controllers/api/v1/trends/statuses_controller.rb
index 3aab92477d..c186864c3b 100644
--- a/app/controllers/api/v1/trends/statuses_controller.rb
+++ b/app/controllers/api/v1/trends/statuses_controller.rb
@@ -1,11 +1,14 @@
 # frozen_string_literal: true
 
 class Api::V1::Trends::StatusesController < Api::BaseController
+  vary_by 'Authorization, Accept-Language'
+
   before_action :set_statuses
 
   after_action :insert_pagination_headers
 
   def index
+    cache_if_unauthenticated!
     render json: @statuses, each_serializer: REST::StatusSerializer
   end
 
diff --git a/app/controllers/api/v1/trends/tags_controller.rb b/app/controllers/api/v1/trends/tags_controller.rb
index 75c3ed218b..aca3dd7089 100644
--- a/app/controllers/api/v1/trends/tags_controller.rb
+++ b/app/controllers/api/v1/trends/tags_controller.rb
@@ -8,6 +8,7 @@ class Api::V1::Trends::TagsController < Api::BaseController
   DEFAULT_TAGS_LIMIT = 10
 
   def index
+    cache_if_unauthenticated!
     render json: @tags, each_serializer: REST::TagSerializer, relationships: TagRelationshipsPresenter.new(@tags, current_user&.account_id)
   end
 
diff --git a/app/controllers/api/v2/instances_controller.rb b/app/controllers/api/v2/instances_controller.rb
index bcd90cff22..8346e28830 100644
--- a/app/controllers/api/v2/instances_controller.rb
+++ b/app/controllers/api/v2/instances_controller.rb
@@ -2,7 +2,7 @@
 
 class Api::V2::InstancesController < Api::V1::InstancesController
   def show
-    expires_in 3.minutes, public: true
+    cache_even_if_authenticated!
     render_with_cache json: InstancePresenter.new, serializer: REST::InstanceSerializer, root: 'instance'
   end
 end
diff --git a/app/controllers/concerns/api_caching_concern.rb b/app/controllers/concerns/api_caching_concern.rb
new file mode 100644
index 0000000000..705abce80f
--- /dev/null
+++ b/app/controllers/concerns/api_caching_concern.rb
@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+module ApiCachingConcern
+  extend ActiveSupport::Concern
+
+  def cache_if_unauthenticated!
+    expires_in(15.seconds, public: true, stale_while_revalidate: 30.seconds, stale_if_error: 1.day) unless user_signed_in?
+  end
+
+  def cache_even_if_authenticated!
+    expires_in(5.minutes, public: true, stale_while_revalidate: 30.seconds, stale_if_error: 1.day) unless whitelist_mode?
+  end
+end