diff --git a/admin/tool/lp/templates/form-user-selector-suggestion.mustache b/admin/tool/lp/templates/form-user-selector-suggestion.mustache
index 61557f9ab1f..015cfda9487 100644
--- a/admin/tool/lp/templates/form-user-selector-suggestion.mustache
+++ b/admin/tool/lp/templates/form-user-selector-suggestion.mustache
@@ -49,7 +49,7 @@
     }
 }}
 <span>
-    <img height="12" src="{{profileimageurlsmall}}" alt="" role="presentation">
+    <img height="12" src="{{profileimageurlsmall}}" alt="">
     <span>{{fullname}}</span>
     {{#hasidentity}}
     <span><small>{{identity}}</small></span>
diff --git a/admin/tool/lp/templates/user_competency_summary_in_course.mustache b/admin/tool/lp/templates/user_competency_summary_in_course.mustache
index dae48ef8bda..5dced42a3fa 100644
--- a/admin/tool/lp/templates/user_competency_summary_in_course.mustache
+++ b/admin/tool/lp/templates/user_competency_summary_in_course.mustache
@@ -49,7 +49,7 @@
         <p>
         <ul class="inline list-inline">
         {{#coursemodules}}
-            <li class="list-inline-item"><a href="{{url}}"><img class="icon" src="{{iconurl}}"> {{name}} </a></li>
+            <li class="list-inline-item"><a href="{{url}}"><img class="icon" src="{{iconurl}}" alt=""> {{name}} </a></li>
         {{/coursemodules}}
         {{^coursemodules}}
             <li class="list-inline-item"><span class="alert">{{#str}}noactivities, tool_lp{{/str}}</span></li>
diff --git a/admin/tool/lp/templates/user_summary.mustache b/admin/tool/lp/templates/user_summary.mustache
index dbcf6397eb9..598f23f9530 100644
--- a/admin/tool/lp/templates/user_summary.mustache
+++ b/admin/tool/lp/templates/user_summary.mustache
@@ -50,7 +50,7 @@
 }}
 <span>
     <a href="{{profileurl}}" title="{{#str}}viewprofile{{/str}}">
-    <img height="18" src="{{profileimageurlsmall}}" alt="" role="presentation">
+    <img height="18" src="{{profileimageurlsmall}}" alt="">
     <span>{{fullname}}</span>
     {{#hasidentity}}
     <span><small>{{identity}}</small></span>
diff --git a/blocks/myoverview/templates/zero-state.mustache b/blocks/myoverview/templates/zero-state.mustache
index 494c0621b8a..b719518362c 100644
--- a/blocks/myoverview/templates/zero-state.mustache
+++ b/blocks/myoverview/templates/zero-state.mustache
@@ -51,8 +51,7 @@
         <div class="text-xs-center text-center mt-3" data-region="empty-message">
             <img class="empty-placeholder-image-lg mt-1"
                     src="{{nocoursesimg}}"
-                    alt="{{{ title }}}"
-                    role="presentation"
+                    alt=""
             >
             <h5 class="h5 mt-3 mb-0">{{{ title }}}</h5>
             <p class="mt-3 mb-0">{{{ intro }}}</p>
diff --git a/blocks/myoverview/tests/behat/block_myoverview_zerostate.feature b/blocks/myoverview/tests/behat/block_myoverview_zerostate.feature
index 4eda8ae1778..79cece88b26 100644
--- a/blocks/myoverview/tests/behat/block_myoverview_zerostate.feature
+++ b/blocks/myoverview/tests/behat/block_myoverview_zerostate.feature
@@ -70,3 +70,8 @@ Feature: Zero state on my overview block
     And "Create course" "button" should exist
     And I click on "Create course" "button"
     And I should see "Add a new course"
+
+  @accessibility
+  Scenario: Evaluate the accessibility of the My courses (zero state)
+    When I am on the "My courses" page logged in as "manager"
+    Then the page should meet accessibility standards
diff --git a/blocks/recentlyaccesseditems/templates/no-items.mustache b/blocks/recentlyaccesseditems/templates/no-items.mustache
index 83ef42afd38..a104252de80 100644
--- a/blocks/recentlyaccesseditems/templates/no-items.mustache
+++ b/blocks/recentlyaccesseditems/templates/no-items.mustache
@@ -27,9 +27,8 @@
 <div class="text-xs-center text-center mt-4" data-region="empty-message">
     <img
         src="{{noitemsimgurl}}"
-        alt="{{#str}} noitems, block_recentlyaccesseditems {{/str}}"
-        role="presentation"
+        alt=""
         style="height: 70px; width: 70px;"
     >
     <p class="text-muted mt-3 mb-0">{{#str}} noitems, block_recentlyaccesseditems {{/str}}</p>
-</div>
\ No newline at end of file
+</div>
diff --git a/blocks/recentlyaccesseditems/templates/view-cards.mustache b/blocks/recentlyaccesseditems/templates/view-cards.mustache
index 33ff9e8ec45..43c07b97c3a 100644
--- a/blocks/recentlyaccesseditems/templates/view-cards.mustache
+++ b/blocks/recentlyaccesseditems/templates/view-cards.mustache
@@ -42,19 +42,21 @@
 
 <div class="card-deck dashboard-card-deck one-row" data-region="items-list" role="list">
     {{#items}}
-        <a class="card dashboard-card mb-1" href="{{{viewurl}}}" title="{{{name}}}" role="listitem">
-            <div class="card-body p-2 m-1">
-                <div class="d-flex text-truncate">
-                    <div class="d-flex align-self-center activityiconcontainer {{purpose}}">
-                        {{{icon}}}
-                    </div>
-                    <div class="w-100 line-height-3 text-truncate ml-2">
-                        <h6 class="mb-0 text-truncate"><span class="clickable">{{{name}}}</span></h6>
-                        <small class="text-truncate mb-0">{{{coursename}}}</small>
+        <div class="card dashboard-card" role="listitem">
+            <a class="mb-1" href="{{{viewurl}}}" title="{{{name}}}">
+                <div class="card-body p-2 m-1">
+                    <div class="d-flex text-truncate">
+                        <div class="d-flex align-self-center activityiconcontainer {{purpose}}">
+                            {{{icon}}}
+                        </div>
+                        <div class="w-100 line-height-3 text-truncate ml-2">
+                            <h6 class="mb-0 text-truncate"><span class="clickable">{{{name}}}</span></h6>
+                            <small class="text-truncate mb-0">{{{coursename}}}</small>
+                        </div>
                     </div>
                 </div>
-            </div>
-        </a>
+            </a>
+        </div>
     {{/items}}
 </div>
 {{#hasmoreitems}}
diff --git a/blocks/recentlyaccesseditems/tests/behat/block_recentlyaccesseditems_dashboard.feature b/blocks/recentlyaccesseditems/tests/behat/block_recentlyaccesseditems_dashboard.feature
index bdcec5ffc05..c0a598b2e99 100644
--- a/blocks/recentlyaccesseditems/tests/behat/block_recentlyaccesseditems_dashboard.feature
+++ b/blocks/recentlyaccesseditems/tests/behat/block_recentlyaccesseditems_dashboard.feature
@@ -23,15 +23,19 @@ Feature: The recently accessed items block allows users to easily access their m
       | name     | Test forum name |
     And I log in as "student1"
 
+  @accessibility
   Scenario: User has not accessed any item
     Then I should see "No recent items" in the "Recently accessed items" "block"
+    And the page should meet accessibility standards
 
+  @accessibility
   Scenario: User has accessed some items
     Given I change window size to "large"
     When I am on the "Test forum name" "forum activity" page
     And I follow "Dashboard"
     Then I should see "Test forum name" in the "Recently accessed items" "block"
     And I should not see "Show more items" in the "Recently accessed items" "block"
+    And the page should meet accessibility standards
 
   Scenario: User has accessed more than 3 items
     Given the following "activities" exist:
diff --git a/blocks/starredcourses/tests/behat/starred_courses.feature b/blocks/starredcourses/tests/behat/starred_courses.feature
new file mode 100644
index 00000000000..6bd79d414db
--- /dev/null
+++ b/blocks/starredcourses/tests/behat/starred_courses.feature
@@ -0,0 +1,42 @@
+@block_starredcourses
+Feature: Starred courses
+  In order for me to quickly navigate to my favourite courses
+  As a user
+  I must be able to add them to the Starred courses block
+
+  Background:
+    Given the following "users" exist:
+      | username | firstname | lastname | email |
+      | student1 | Student | 1 | student1@example.com |
+    And the following "courses" exist:
+      | shortname | fullname |
+      | C1        | Course 1 |
+      | C2        | Course 2 |
+      | C3        | Course 3 |
+    And the following "course enrolments" exist:
+      | user      | course | role    |
+      | student1  | C1     | student |
+      | student1  | C2     | student |
+      | student1  | C3     | student |
+    And the following "blocks" exist:
+      | blockname       | contextlevel | reference | pagetypepattern | defaultregion  |
+      | starredcourses  | User         | student1  | my-index        | content        |
+
+  @accessibility @javascript
+  Scenario: User has no starred courses
+    Given I log in as "student1"
+    Then I should see "No starred courses"
+    And the page should meet accessibility standards
+
+  @accessibility @javascript
+  Scenario: User has starred courses
+    Given I am on the "My courses" page logged in as "student1"
+    And I click on "Actions for course Course 1" "button"
+    And I click on "Star for Course 1" "link"
+    And I click on "Actions for course Course 3" "button"
+    And I click on "Star for Course 3" "link"
+    When I follow "Dashboard"
+    Then the page should meet accessibility standards
+    And I should see "Course 1" in the "Starred courses" "block"
+    And I should see "Course 3" in the "Starred courses" "block"
+    But I should not see "Course 2" in the "Starred courses" "block"
diff --git a/completion/tests/behat/bulk_edit_activity_completion.feature b/completion/tests/behat/bulk_edit_activity_completion.feature
index 869f07ca57a..734785d6ae4 100644
--- a/completion/tests/behat/bulk_edit_activity_completion.feature
+++ b/completion/tests/behat/bulk_edit_activity_completion.feature
@@ -86,3 +86,10 @@ Feature: Allow teachers to bulk edit activity completion rules in a course.
     And I should see "With conditions" in the "//div[contains(concat(' ', normalize-space(@class), ' '), ' row ')][.//*[text() = 'Test assignment two']]" "xpath_element"
     And I should see "Student must receive a passing grade to complete this activity" in the "//div[contains(concat(' ', normalize-space(@class), ' '), ' row ')][.//*[text() = 'Test assignment two']]" "xpath_element"
     And I should not see "Completion expected on" in the "//div[contains(concat(' ', normalize-space(@class), ' '), ' row ')][.//*[text() = 'Test assignment two']]" "xpath_element"
+
+  @accessibility
+  Scenario: Evaluate the accessibility of the bulk edit activity completion page
+    Given I am on the "Course 1" course page logged in as "teacher1"
+    When I navigate to "Course completion" in current page administration
+    And I set the field "Course completion tertiary navigation" to "Bulk edit activity completion"
+    And the page should meet "wcag21aa" accessibility standards
diff --git a/completion/tests/behat/default_activity_completion.feature b/completion/tests/behat/default_activity_completion.feature
index 779ec7b75ea..185520e85d8 100644
--- a/completion/tests/behat/default_activity_completion.feature
+++ b/completion/tests/behat/default_activity_completion.feature
@@ -82,3 +82,19 @@ Feature: Allow teachers to edit the default activity completion rules in a cours
     And I click on "Save changes" "button"
     Then I should see "Changes saved"
     And I should see "Student must achieve at least one of the following statuses: Completed"
+
+  @javascript @accessibility
+  Scenario: Evaluate the accessibility of the default activity completion page
+    Given the following "courses" exist:
+      | fullname | shortname | category | enablecompletion |
+      | Course 1 | C1        | 0        | 1                |
+    And the following "users" exist:
+      | username | firstname | lastname | email |
+      | teacher1 | Teacher | First | teacher1@example.com |
+    And the following "course enrolments" exist:
+      | user     | course | role           |
+      | teacher1 | C1     | editingteacher |
+    And I am on the "Course 1" course page logged in as teacher1
+    When I navigate to "Course completion" in current page administration
+    And I select "Default activity completion" from the "Course completion tertiary navigation" singleselect
+    And the page should meet accessibility standards
diff --git a/course/renderer.php b/course/renderer.php
index ed3eefee134..4e064179a1a 100644
--- a/course/renderer.php
+++ b/course/renderer.php
@@ -697,8 +697,7 @@ class core_course_renderer extends plugin_renderer_base {
         // Display link itself.
         $instancename = html_writer::tag('span', $instancename . $altname, ['class' => 'instancename ml-1']);
 
-        $imageicon = html_writer::empty_tag('img', ['src' => $mod->get_icon_url(),
-            'class' => 'activityicon', 'alt' => '', 'role' => 'presentation', 'aria-hidden' => 'true']);
+        $imageicon = html_writer::empty_tag('img', ['src' => $mod->get_icon_url(), 'class' => 'activityicon', 'alt' => '']);
         $imageicon = html_writer::tag('span', $imageicon, ['class' => 'activityiconcontainer courseicon']);
         $activitylink = $imageicon . $instancename;
 
@@ -907,7 +906,7 @@ class core_course_renderer extends plugin_renderer_base {
 
         $altname = get_accesshide(' ' . $cm->modfullname);
         $name = html_writer::empty_tag('img', array('src' => $cm->get_icon_url(),
-                'class' => 'iconlarge activityicon', 'alt' => ' ', 'role' => 'presentation')) .
+                'class' => 'iconlarge activityicon', 'alt' => '')) .
             html_writer::tag('span', ' '.$cm->get_formatted_name() . $altname, array('class' => 'instancename'));
         $formattedinfo = \core_availability\info::format_info($cm->availableinfo, $cm->get_course());
         return html_writer::div($name, 'activityinstance-error') .
diff --git a/course/templates/activityinstance.mustache b/course/templates/activityinstance.mustache
index 18342323f30..7d1673cd0c5 100644
--- a/course/templates/activityinstance.mustache
+++ b/course/templates/activityinstance.mustache
@@ -42,7 +42,7 @@
             <input type="checkbox" id="selectactivity_{{cmid}}" class="mr-1" name="cmid[]" data-section="{{sectionnumber}}" value="{{cmid}}" aria-label="{{#str}}checkactivity, completion, {{{modname}}}{{/str}}">
             {{/canmanage}}
             <a href="{{url}}">
-            <img src="{{icon}}" class="iconlarge activityicon" alt=" " role="presentation" />
+            <img src="{{icon}}" class="iconlarge activityicon" alt="">
             <span class="instancename">{{{modname}}}</span>
             </a>
         </div>
diff --git a/course/templates/defaultactivitycompletion.mustache b/course/templates/defaultactivitycompletion.mustache
index f744f05c522..fe7458405eb 100644
--- a/course/templates/defaultactivitycompletion.mustache
+++ b/course/templates/defaultactivitycompletion.mustache
@@ -47,8 +47,10 @@
     </div>
     <div class="row mb-1">
         <div class="col-6">
-            <input type="checkbox" class="mastercheck mr-1" aria-label="{{#str}}checkall, completion{{/str}}">
-            <label class="font-weight-bold">{{#str}}activitieslabel, core_completion{{/str}}</label>
+            <label class="font-weight-bold">
+                <input type="checkbox" class="mastercheck mr-1" aria-label="{{#str}}checkall, completion{{/str}}">
+                {{#str}}activitieslabel, core_completion{{/str}}
+            </label>
         </div>
         <div class="col-6">
             <label class="font-weight-bold">{{#str}}completion, core_completion{{/str}}</label>
@@ -62,10 +64,11 @@
              <div class="mb-1">
                 <div class="row mb-1">
                     <div class="col-6">
-                        <label class="accesshide" for="modtype_{{id}}">{{#str}}select, core_completion{{/str}} {{formattedname}}</label>
-                        <input id="modtype_{{id}}" type="checkbox" class="mr-1" name="modids[]" value="{{id}}" aria-label="{{#str}}checkactivity, completion, {{{formattedname}}}{{/str}}">
-                        <img class="iconlarge activityicon" src="{{icon}}" alt=" " role="presentation" />
-                        <span>{{{formattedname}}}</span>
+                        <label for="modtype_{{id}}">
+                            <input id="modtype_{{id}}" type="checkbox" class="mr-1" name="modids[]" value="{{id}}" aria-label="{{#str}}checkactivity, completion, {{{formattedname}}}{{/str}}">
+                            <img class="iconlarge activityicon" src="{{icon}}" alt="" />
+                            <span>{{{formattedname}}}</span>
+                        </label>
                     </div>
                     <div class="activity-completionstatus col-6">
                         <div class="col-sm-1 pl-0">
diff --git a/course/templates/editdefaultcompletion.mustache b/course/templates/editdefaultcompletion.mustache
index ee6b0346f98..da2e70e70b5 100644
--- a/course/templates/editdefaultcompletion.mustache
+++ b/course/templates/editdefaultcompletion.mustache
@@ -38,7 +38,7 @@
         <div class="row mb-1">
             {{#modules}}
                 <div class="col-sm-2">
-                    <img src="{{icon}}" class="mr-1 mb-1" alt=" " role="presentation" />
+                    <img src="{{icon}}" class="mr-1 mb-1" alt="">
                     <span>{{{formattedname}}}</span>
                 </div>
             {{/modules}}
diff --git a/course/templates/no-courses.mustache b/course/templates/no-courses.mustache
index 1b7007a5128..90a8ce7363a 100644
--- a/course/templates/no-courses.mustache
+++ b/course/templates/no-courses.mustache
@@ -28,10 +28,9 @@
 <div class="text-xs-center text-center mt-3" data-region="empty-message">
     <img class="empty-placeholder-image-lg mt-1"
          src="{{nocoursesimg}}"
-         alt="{{$nocoursestring}}{{#str}} nocourses, core {{/str}}{{/nocoursestring}}"
-         role="presentation">
+         alt="">
     <p class="text-muted mt-3">{{$nocoursestring}}{{#str}} nocourses, core {{/str}}{{/nocoursestring}}</p>
     {{#newcourseurl}}
         <a href="{{{newcourseurl}}}" class="nocourseslink">{{#str}} createnewcourse, core {{/str}}</a>
     {{/newcourseurl}}
-</div>
\ No newline at end of file
+</div>
diff --git a/enrol/manual/templates/form-user-selector-suggestion.mustache b/enrol/manual/templates/form-user-selector-suggestion.mustache
index ab9b862b0ad..91d288d3233 100644
--- a/enrol/manual/templates/form-user-selector-suggestion.mustache
+++ b/enrol/manual/templates/form-user-selector-suggestion.mustache
@@ -49,7 +49,7 @@
     }
 }}
 <span>
-    <img height="12" src="{{profileimageurlsmall}}" alt="" role="presentation">
+    <img height="12" src="{{profileimageurlsmall}}" alt="">
     <span>{{fullname}}</span>
     {{#hasidentity}}
     <span><small>{{identity}}</small></span>
diff --git a/lib/adminlib.php b/lib/adminlib.php
index 195888c8e7f..974e41f899c 100644
--- a/lib/adminlib.php
+++ b/lib/adminlib.php
@@ -10915,7 +10915,7 @@ class admin_setting_php_extension_enabled extends admin_setting {
 
         $o = '';
         if (!extension_loaded($this->extension)) {
-            $warning = $OUTPUT->pix_icon('i/warning', '', '', array('role' => 'presentation')) . ' ' . $this->description;
+            $warning = $OUTPUT->pix_icon('i/warning', '') . ' ' . $this->description;
 
             $o .= format_admin_setting($this, $this->visiblename, $warning);
         }
diff --git a/lib/outputcomponents.php b/lib/outputcomponents.php
index d568c851b23..5f2519d5339 100644
--- a/lib/outputcomponents.php
+++ b/lib/outputcomponents.php
@@ -1830,7 +1830,15 @@ class html_writer {
     public static function img($src, $alt, array $attributes = null) {
         $attributes = (array)$attributes;
         $attributes['src'] = $src;
-        $attributes['alt'] = $alt;
+        // In case a null alt text is provided, set it to an empty string.
+        $attributes['alt'] = $alt ?? '';
+        if (array_key_exists('role', $attributes) && core_text::strtolower($attributes['role']) === 'presentation') {
+            // A presentation role is not necessary for the img tag.
+            // If a non-empty alt text is provided, the presentation role will conflict with the alt text.
+            // An empty alt text denotes a decorative image. The presence of a presentation role is redundant.
+            unset($attributes['role']);
+            debugging('The presentation role is not necessary for an img tag.', DEBUG_DEVELOPER);
+        }
 
         return self::empty_tag('img', $attributes);
     }
diff --git a/lib/outputrenderers.php b/lib/outputrenderers.php
index 1e0cec0fb18..fae94e48b58 100644
--- a/lib/outputrenderers.php
+++ b/lib/outputrenderers.php
@@ -2049,14 +2049,19 @@ class core_renderer extends renderer_base {
             $attributes['class'] = 'action-icon';
         }
 
-        $icon = $this->render($pixicon);
-
         if ($linktext) {
             $text = $pixicon->attributes['alt'];
+            // Set the icon as a decorative image if we're displaying the action text.
+            // Otherwise, the action name will be read twice by assistive technologies.
+            $pixicon->attributes['alt'] = '';
+            $pixicon->attributes['title'] = '';
+            $pixicon->attributes['aria-hidden'] = 'true';
         } else {
             $text = '';
         }
 
+        $icon = $this->render($pixicon);
+
         return $this->action_link($url, $text.$icon, $action, $attributes);
     }
 
@@ -2294,7 +2299,7 @@ class core_renderer extends renderer_base {
     public function doc_link($path, $text = '', $forcepopup = false, array $attributes = []) {
         global $CFG;
 
-        $icon = $this->pix_icon('book', '', 'moodle', array('class' => 'iconhelp icon-pre', 'role' => 'presentation'));
+        $icon = $this->pix_icon('book', '', 'moodle', array('class' => 'iconhelp icon-pre'));
 
         $attributes['href'] = new moodle_url(get_docs_url($path));
         $newwindowicon = '';
@@ -4528,15 +4533,14 @@ EOD;
                     if ($button['buttontype'] === 'message') {
                         \core_message\helper::messageuser_requirejs();
                     }
-                    $image = $this->pix_icon($button['formattedimage'], $button['title'], 'moodle', array(
+                    $image = $this->pix_icon($button['formattedimage'], '', 'moodle', array(
                         'class' => 'iconsmall',
-                        'role' => 'presentation'
                     ));
                     $image .= html_writer::span($button['title'], 'header-button-title');
                 } else {
                     $image = html_writer::empty_tag('img', array(
                         'src' => $button['formattedimage'],
-                        'role' => 'presentation'
+                        'alt' => $button['title'],
                     ));
                 }
                 $html .= html_writer::link($button['url'], html_writer::tag('span', $image), $button['linkattributes']);
diff --git a/lib/tests/weblib_test.php b/lib/tests/weblib_test.php
index f553acaf397..81f83517402 100644
--- a/lib/tests/weblib_test.php
+++ b/lib/tests/weblib_test.php
@@ -1186,9 +1186,9 @@ EXPECTED;
         $url1 = "{$CFG->wwwroot}/draftfile.php/5/user/draft/99999999/test1.jpg";
         $url2 = "{$CFG->wwwroot}/draftfile.php/5/user/draft/99999998/test2.jpg";
 
-        $html = "<p>This is a test.</p><p><img src=\"{$url1}\" alt=\"\" role=\"presentation\"></p>
+        $html = "<p>This is a test.</p><p><img src=\"{$url1}\" alt=\"\"></p>
                 <br>Test content.<p></p><p><img src=\"{$url2}\" alt=\"\" width=\"2048\" height=\"1536\"
-                role=\"presentation\" class=\"img-fluid atto_image_button_text-bottom\"><br></p>";
+                class=\"img-fluid atto_image_button_text-bottom\"><br></p>";
         $draftareas = array(
             array(
                 'urlbase' => 'draftfile.php',
diff --git a/message/templates/add_contact_button.mustache b/message/templates/add_contact_button.mustache
index f4972a58d98..b26ebf427be 100644
--- a/message/templates/add_contact_button.mustache
+++ b/message/templates/add_contact_button.mustache
@@ -28,7 +28,12 @@
     }
 }}
 <span>
-    {{#pix}} t/addcontact, core, {{#str}} addtoyourcontacts, message {{/str}} {{/pix}}
-    {{#displaytextlabel}}<span class="header-button-title">{{#str}} addtoyourcontacts, message {{/str}}</span>{{/displaytextlabel}}
+    {{^displaytextlabel}}
+        {{#pix}} t/addcontact, core, {{#str}} addtoyourcontacts, message {{/str}} {{/pix}}
+    {{/displaytextlabel}}
+    {{#displaytextlabel}}
+        {{#pix}} t/addcontact, core {{/pix}}
+        <span class="header-button-title">{{#str}} addtoyourcontacts, message {{/str}}</span>
+    {{/displaytextlabel}}
 </span>
 {{> core/loading }}
diff --git a/message/templates/remove_contact_button.mustache b/message/templates/remove_contact_button.mustache
index 4373be4beb0..53800467ae8 100644
--- a/message/templates/remove_contact_button.mustache
+++ b/message/templates/remove_contact_button.mustache
@@ -28,7 +28,12 @@
     }
 }}
 <span>
-    {{#pix}} t/removecontact, core, {{#str}} removefromyourcontacts, message {{/str}} {{/pix}}
-    {{#displaytextlabel}}<span class="header-button-title">{{#str}} removefromyourcontacts, message {{/str}}</span>{{/displaytextlabel}}
+    {{^displaytextlabel}}
+        {{#pix}} t/removecontact, core, {{#str}} removefromyourcontacts, message {{/str}} {{/pix}}
+    {{/displaytextlabel}}
+    {{#displaytextlabel}}
+        {{#pix}} t/removecontact, core {{/pix}}
+        <span class="header-button-title">{{#str}} removefromyourcontacts, message {{/str}}</span>
+    {{/displaytextlabel}}
 </span>
 {{> core/loading }}
diff --git a/message/tests/behat/self_conversation.feature b/message/tests/behat/self_conversation.feature
index ea612d2b6c2..deebd39df4b 100644
--- a/message/tests/behat/self_conversation.feature
+++ b/message/tests/behat/self_conversation.feature
@@ -61,7 +61,7 @@ Feature: Self conversation
     Given I log in as "student1"
     When I follow "Profile" in the user menu
     Then I should see "Message"
-    And I click on "Message" "icon"
+    And I press "Message"
     And I send "Hi!" message in the message area
     And I should see "Hi!" in the "Student 1" "core_message > Message conversation"
     And I should see "##today##%d %B##" in the "Student 1" "core_message > Message conversation"
diff --git a/mod/data/templates/view_noentries.mustache b/mod/data/templates/view_noentries.mustache
index ae3a196f707..5a0fc957819 100644
--- a/mod/data/templates/view_noentries.mustache
+++ b/mod/data/templates/view_noentries.mustache
@@ -55,14 +55,8 @@
     }
 }}
 <div class="text-xs-center text-center mt-4" data-region="empty-message">
-    <img
-            src="{{noitemsimgurl}}"
-            alt="{{#str}} norecords, mod_data {{/str}}"
-            role="presentation"
-            style="height: 70px; width: 70px;"
-    >
+    <img src="{{noitemsimgurl}}" alt="" style="height: 70px; width: 70px;">
     <h5 class="h5 mt-3 mb-0">{{#str}} norecords, mod_data {{/str}}</h5>
-
     <div class="mt-5 mb-0" id="action_bar">
         {{#importentriesbutton}}
             {{> core/single_button }}
diff --git a/mod/data/templates/zero_state.mustache b/mod/data/templates/zero_state.mustache
index fd65758acd1..deb4543fde0 100644
--- a/mod/data/templates/zero_state.mustache
+++ b/mod/data/templates/zero_state.mustache
@@ -71,12 +71,7 @@
     }
 }}
 <div class="text-xs-center text-center mt-4" data-region="empty-message">
-    <img
-            src="{{noitemsimgurl}}"
-            alt="{{{ title }}}"
-            role="presentation"
-            style="height: 70px; width: 70px;"
-    >
+    <img src="{{noitemsimgurl}}" alt="" style="height: 70px; width: 70px;">
     <h5 class="h5 mt-3 mb-0">{{{ title }}}</h5>
     {{#intro}}
         <p class="mt-3 mb-0">{{{ intro }}}</p>
diff --git a/mod/data/tests/behat/view_entries.feature b/mod/data/tests/behat/view_entries.feature
index 2c014305f46..82d938d7161 100644
--- a/mod/data/tests/behat/view_entries.feature
+++ b/mod/data/tests/behat/view_entries.feature
@@ -191,3 +191,18 @@ Feature: Users can view and search database entries
       | param1 | param3 | autolink   |
       | 0      | 0      | should not |
       | 1      | 1      | should     |
+
+  @javascript @accessibility
+  Scenario: Check the accessibility of the database entries page (zero state)
+    When I am on the "Test database name" "data activity" page logged in as "teacher1"
+    Then I should see "No entries yet"
+    And the page should meet accessibility standards
+
+  @javascript @accessibility
+  Scenario: Check the accessibility of the database entries page
+    Given the following "mod_data > entries" exist:
+      | database | user     | Test field name | Test field 2 name      | Test field 3 name |
+      | data1    | student1 | Student entry 1 | Some student content 1 | http://moodle.com |
+      | data1    | teacher1 | Teacher entry 2 | Some teacher content 2 | http://moodle.com |
+    When I am on the "Test database name" "data activity" page logged in as teacher1
+    Then the page should meet accessibility standards
diff --git a/mod/data/tests/behat/zero_state.feature b/mod/data/tests/behat/zero_state.feature
index 4d5b385d40f..8ee696ce343 100644
--- a/mod/data/tests/behat/zero_state.feature
+++ b/mod/data/tests/behat/zero_state.feature
@@ -65,3 +65,9 @@ Feature: Zero state page (no fields created)
     Then I click on "Use this preset" "button"
     And I should not see "Field mappings"
     And I should see "Image" in the "image" "table_row"
+
+  @javascript @accessibility
+  Scenario: Check the accessibility of the database activity zero state
+    When I am on the "Test database name" "data activity" page logged in as "teacher1"
+    Then I should see "Start building your activity"
+    And the page should meet accessibility standards
diff --git a/mod/quiz/classes/output/edit_renderer.php b/mod/quiz/classes/output/edit_renderer.php
index ce376dfb9ba..a2855247cc8 100644
--- a/mod/quiz/classes/output/edit_renderer.php
+++ b/mod/quiz/classes/output/edit_renderer.php
@@ -1035,7 +1035,7 @@ class edit_renderer extends \plugin_renderer_base {
         $namestr = $qtype->local_name();
 
         $icon = $this->pix_icon('icon', $namestr, $qtype->plugin_name(), ['title' => $namestr,
-                'class' => 'activityicon', 'alt' => ' ', 'role' => 'presentation']);
+                'class' => 'activityicon', 'alt' => $namestr]);
 
         $editicon = $this->pix_icon('t/edit', '', 'moodle', ['title' => '']);
 
@@ -1073,8 +1073,7 @@ class edit_renderer extends \plugin_renderer_base {
         $configuretitle = get_string('configurerandomquestion', 'quiz');
         $qtype = \question_bank::get_qtype($question->qtype, false);
         $namestr = $qtype->local_name();
-        $icon = $this->pix_icon('icon', $namestr, $qtype->plugin_name(), ['title' => $namestr,
-                'class' => 'icon activityicon', 'alt' => ' ', 'role' => 'presentation']);
+        $icon = $this->pix_icon('icon', $namestr, $qtype->plugin_name(), ['class' => 'icon activityicon']);
 
         $editicon = $this->pix_icon('t/edit', $configuretitle, 'moodle', ['title' => '']);
         $qbankurlparams = [
diff --git a/mod/quiz/tests/behat/editing_add.feature b/mod/quiz/tests/behat/editing_add.feature
index 7fca18fe8bf..12ff21fcb54 100644
--- a/mod/quiz/tests/behat/editing_add.feature
+++ b/mod/quiz/tests/behat/editing_add.feature
@@ -242,3 +242,19 @@ Feature: Edit quiz page - adding things
     And I should see "Essay 02" on quiz page "3"
     And I should see "Random" on quiz page "4"
     And I should see "Essay for page 4" on quiz page "4"
+
+  @accessibility @javascript
+  Scenario: Check the accessibility of the quiz questions page
+    Given the following "question categories" exist:
+      | contextlevel | reference | name           |
+      | Course       | C1        | Test questions |
+    And the following "questions" exist:
+      | questioncategory | qtype     | name           | questiontext              |
+      | Test questions   | truefalse | First question | Answer the first question |
+      | Test questions   | truefalse | Other question | Answer the first question |
+    And quiz "Quiz 1" contains the following questions:
+      | question          | page |
+      | First question    | 1    |
+    When I reload the page
+    Then I should see "First question"
+    And the page should meet accessibility standards
diff --git a/mod/workshop/renderer.php b/mod/workshop/renderer.php
index d6dcb95ce7a..77d2c75ca7c 100644
--- a/mod/workshop/renderer.php
+++ b/mod/workshop/renderer.php
@@ -308,7 +308,7 @@ class mod_workshop_renderer extends plugin_renderer_base {
 
             if ($phase->active) {
                 // Mark the section as the current one.
-                $icon = $this->output->pix_icon('i/marked', '', 'moodle', ['role' => 'presentation']);
+                $icon = $this->output->pix_icon('i/marked', '');
                 $actions .= get_string('userplancurrentphase', 'workshop').' '.$icon;
 
             } else {
diff --git a/report/competency/tests/behat/breakdown_by_activity.feature b/report/competency/tests/behat/breakdown_by_activity.feature
index d61e0749bf6..0ea7be784e1 100644
--- a/report/competency/tests/behat/breakdown_by_activity.feature
+++ b/report/competency/tests/behat/breakdown_by_activity.feature
@@ -65,3 +65,10 @@ Feature: See the competencies for an activity
     And I click on "PageName1" "autocomplete_selection"
     And I should see "Test-Comp1"
     And I should see "Test-Comp2"
+
+  @accessibility
+  Scenario: Evaluate the accessibility of the user competency summary dialogue
+    Given I navigate to "Reports" in current page administration
+    When I click on "Competency breakdown" "link"
+    And I click on "Not rated" "link"
+    And the page should meet accessibility standards
diff --git a/search/templates/form-user-selector-suggestion.mustache b/search/templates/form-user-selector-suggestion.mustache
index 08a5912470a..f3d5407f734 100644
--- a/search/templates/form-user-selector-suggestion.mustache
+++ b/search/templates/form-user-selector-suggestion.mustache
@@ -36,6 +36,6 @@
     }
 }}
 <span>
-    <img height="12" src="{{profileimageurlsmall}}" alt="" role="presentation">
+    <img height="12" src="{{profileimageurlsmall}}" alt="">
     <span>{{fullname}}</span>
 </span>
diff --git a/theme/boost/classes/output/core_renderer.php b/theme/boost/classes/output/core_renderer.php
index 7453f8ff89a..77206eca217 100644
--- a/theme/boost/classes/output/core_renderer.php
+++ b/theme/boost/classes/output/core_renderer.php
@@ -224,15 +224,14 @@ class core_renderer extends \core_renderer {
                     if ($button['buttontype'] === 'message') {
                         \core_message\helper::messageuser_requirejs();
                     }
-                    $image = $this->pix_icon($button['formattedimage'], $button['title'], 'moodle', array(
+                    $image = $this->pix_icon($button['formattedimage'], '', 'moodle', array(
                         'class' => 'iconsmall',
-                        'role' => 'presentation'
                     ));
                     $image .= html_writer::span($button['title'], 'header-button-title');
                 } else {
                     $image = html_writer::empty_tag('img', array(
                         'src' => $button['formattedimage'],
-                        'role' => 'presentation'
+                        'alt' => $button['title'],
                     ));
                 }
                 $html .= html_writer::link($button['url'], html_writer::tag('span', $image), $button['linkattributes']);