diff --git a/guides/source/4_1_release_notes.md b/guides/source/4_1_release_notes.md
index c7b82c4d42..3d80beb71a 100644
--- a/guides/source/4_1_release_notes.md
+++ b/guides/source/4_1_release_notes.md
@@ -182,7 +182,7 @@ Conversation.statuses # => { "active" => 0, "archived" => 1 }
 ```
 
 See its
-[documentation](http://api.rubyonrails.org/v4.1.0/classes/ActiveRecord/Enum.html)
+[documentation](https://api.rubyonrails.org/v4.1.0/classes/ActiveRecord/Enum.html)
 for a detailed write up.
 
 ### Message Verifiers
@@ -338,7 +338,7 @@ for detailed changes.
   array. ([Pull Request](https://github.com/rails/rails/pull/9599))
 
 * Added `session#fetch` method fetch behaves similarly to
-  [Hash#fetch](http://www.ruby-doc.org/core-1.9.3/Hash.html#method-i-fetch),
+  [Hash#fetch](https://www.ruby-doc.org/core-1.9.3/Hash.html#method-i-fetch),
   with the exception that the returned value is always saved into the
   session. ([Pull Request](https://github.com/rails/rails/pull/12692))
 
diff --git a/guides/source/4_2_release_notes.md b/guides/source/4_2_release_notes.md
index 80f68f249e..f763630d3f 100644
--- a/guides/source/4_2_release_notes.md
+++ b/guides/source/4_2_release_notes.md
@@ -256,7 +256,7 @@ deprecation warnings because it is opt-in.
 `rails-deprecated_sanitizer` will be supported for Rails 4.2 only; it will not
 be maintained for Rails 5.0.
 
-See [this blog post](http://blog.plataformatec.com.br/2014/07/the-new-html-sanitizer-in-rails-4-2/)
+See [this blog post](https://blog.plataformatec.com.br/2014/07/the-new-html-sanitizer-in-rails-4-2/)
 for more details on the changes in the new sanitizer.
 
 ### `assert_select`
diff --git a/guides/source/5_1_release_notes.md b/guides/source/5_1_release_notes.md
index 2a23edc07c..6ef9f98a21 100644
--- a/guides/source/5_1_release_notes.md
+++ b/guides/source/5_1_release_notes.md
@@ -144,9 +144,9 @@ This will generate the singular URL `/basket` instead of the usual `/baskets/:id
 The `direct` method allows creation of custom URL helpers.
 
 ```ruby
-direct(:homepage) { "http://www.rubyonrails.org" }
+direct(:homepage) { "https://rubyonrails.org" }
 
-homepage_url # => "http://www.rubyonrails.org"
+homepage_url # => "https://rubyonrails.org"
 ```
 
 The return value of the block must be a valid argument for the `url_for`
diff --git a/guides/source/active_record_postgresql.md b/guides/source/active_record_postgresql.md
index 60e765f4f2..85777e4076 100644
--- a/guides/source/active_record_postgresql.md
+++ b/guides/source/active_record_postgresql.md
@@ -448,10 +448,10 @@ A point is casted to an array containing `x` and `y` coordinates.
 
 ### Interval
 
-* [type definition](http://www.postgresql.org/docs/current/static/datatype-datetime.html#DATATYPE-INTERVAL-INPUT)
-* [functions and operators](http://www.postgresql.org/docs/current/static/functions-datetime.html)
+* [type definition](https://www.postgresql.org/docs/current/static/datatype-datetime.html#DATATYPE-INTERVAL-INPUT)
+* [functions and operators](https://www.postgresql.org/docs/current/static/functions-datetime.html)
 
-This type is mapped to [`ActiveSupport::Duration`](http://api.rubyonrails.org/classes/ActiveSupport/Duration.html) objects.
+This type is mapped to [`ActiveSupport::Duration`](https://api.rubyonrails.org/classes/ActiveSupport/Duration.html) objects.
 
 ```ruby
 # db/migrate/20200120000000_create_events.rb
diff --git a/guides/source/routing.md b/guides/source/routing.md
index 98e0df7f23..bc51e8f97a 100644
--- a/guides/source/routing.md
+++ b/guides/source/routing.md
@@ -974,11 +974,11 @@ You can create custom URL helpers directly by calling [`direct`][]. For example:
 
 ```ruby
 direct :homepage do
-  "http://www.rubyonrails.org"
+  "https://rubyonrails.org"
 end
 
 # >> homepage_url
-# => "http://www.rubyonrails.org"
+# => "https://rubyonrails.org"
 ```
 
 The return value of the block must be a valid argument for the `url_for` method. So, you can pass a valid string URL, Hash, Array, an Active Model instance, or an Active Model class.
diff --git a/guides/source/testing.md b/guides/source/testing.md
index 92b2739abd..603d8ef367 100644
--- a/guides/source/testing.md
+++ b/guides/source/testing.md
@@ -355,7 +355,7 @@ Rails adds some custom assertions of its own to the `minitest` framework:
 | [`assert_nothing_raised { block }`](https://api.rubyonrails.org/classes/ActiveSupport/Testing/Assertions.html#method-i-assert_nothing_raised) | Ensures that the given block doesn't raise any exceptions.|
 | [`assert_recognizes(expected_options, path, extras={}, message=nil)`](https://api.rubyonrails.org/classes/ActionDispatch/Assertions/RoutingAssertions.html#method-i-assert_recognizes) | Asserts that the routing of the given path was handled correctly and that the parsed options (given in the expected_options hash) match path. Basically, it asserts that Rails recognizes the route given by expected_options.|
 | [`assert_generates(expected_path, options, defaults={}, extras = {}, message=nil)`](https://api.rubyonrails.org/classes/ActionDispatch/Assertions/RoutingAssertions.html#method-i-assert_generates) | Asserts that the provided options can be used to generate the provided path. This is the inverse of assert_recognizes. The extras parameter is used to tell the request the names and values of additional request parameters that would be in a query string. The message parameter allows you to specify a custom error message for assertion failures.|
-| [`assert_response(type, message = nil)`](https://api.rubyonrails.org/classes/ActionDispatch/Assertions/ResponseAssertions.html#method-i-assert_response) | Asserts that the response comes with a specific status code. You can specify `:success` to indicate 200-299, `:redirect` to indicate 300-399, `:missing` to indicate 404, or `:error` to match the 500-599 range. You can also pass an explicit status number or its symbolic equivalent. For more information, see [full list of status codes](http://rubydoc.info/github/rack/rack/master/Rack/Utils#HTTP_STATUS_CODES-constant) and how their [mapping](https://rubydoc.info/github/rack/rack/master/Rack/Utils#SYMBOL_TO_STATUS_CODE-constant) works.|
+| [`assert_response(type, message = nil)`](https://api.rubyonrails.org/classes/ActionDispatch/Assertions/ResponseAssertions.html#method-i-assert_response) | Asserts that the response comes with a specific status code. You can specify `:success` to indicate 200-299, `:redirect` to indicate 300-399, `:missing` to indicate 404, or `:error` to match the 500-599 range. You can also pass an explicit status number or its symbolic equivalent. For more information, see [full list of status codes](https://rubydoc.info/github/rack/rack/master/Rack/Utils#HTTP_STATUS_CODES-constant) and how their [mapping](https://rubydoc.info/github/rack/rack/master/Rack/Utils#SYMBOL_TO_STATUS_CODE-constant) works.|
 | [`assert_redirected_to(options = {}, message=nil)`](https://api.rubyonrails.org/classes/ActionDispatch/Assertions/ResponseAssertions.html#method-i-assert_redirected_to) | Asserts that the response is a redirect to a URL matching the given options. You can also pass named routes such as `assert_redirected_to root_path` and Active Record objects such as `assert_redirected_to @article`.|
 
 You'll see the usage of some of these assertions in the next chapter.