diff --git a/Dangerfile b/Dangerfile
index 287bd7361a..787af78eaa 100644
--- a/Dangerfile
+++ b/Dangerfile
@@ -1,6 +1,6 @@
 # This file is written on Ruby language.
-# Here is a quick Ruby overview: http://danger.systems/guides/a_quick_ruby_overview.html
-# See also Danger specific methods: http://danger.systems/reference.html
+# Here is a quick Ruby overview: https://danger.systems/guides/a_quick_ruby_overview.html
+# See also Danger specific methods: https://danger.systems/reference.html
 
 # We we'll use nokogiri for parsing XML
 # Here is a good introduction: https://blog.engineyard.com/2010/getting-started-with-nokogiri
diff --git a/README.md b/README.md
index 43e7b1ccad..ee0526b391 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,7 @@
 # My Stamps
 
 [![Build Status](https://travis-ci.org/php-coder/mystamps.svg?branch=master)](https://travis-ci.org/php-coder/mystamps)
-[![PDD Status](http://www.0pdd.com/svg?name=php-coder/mystamps)](http://www.0pdd.com/p?name=php-coder/mystamps)
+[![PDD Status](https://www.0pdd.com/svg?name=php-coder/mystamps)](https://www.0pdd.com/p?name=php-coder/mystamps)
 [![Quality Gate Status](https://sonarcloud.io/api/project_badges/measure?project=ru.mystamps%3Amystamps&metric=alert_status)](https://sonarcloud.io/dashboard?id=ru.mystamps%3Amystamps)
 [![Uptime Statistic](https://badgen.net/uptime-robot/month/ur243278-551fbb732949dbdee27c7552)](https://stats.uptimerobot.com/1jXAjFpgP)
 
diff --git a/infra/vagrant/provisioning/roles/mystamps-backup/defaults/main.yml b/infra/vagrant/provisioning/roles/mystamps-backup/defaults/main.yml
index 355b1203ba..4bb9f065d1 100644
--- a/infra/vagrant/provisioning/roles/mystamps-backup/defaults/main.yml
+++ b/infra/vagrant/provisioning/roles/mystamps-backup/defaults/main.yml
@@ -2,7 +2,7 @@
 admin_email: coder
 user_db_password: p@ssword
 # Target urls should be in a format that is supported by duplicity(1):
-# http://www.nongnu.org/duplicity/duplicity.1.html#sect7
+# https://www.nongnu.org/duplicity/vers8/duplicity.1.html#sect7
 uploads_target_url: file:///tmp/uploads
 mysql_backups_target_url: file:///tmp/mysql-backups
 # Passphrase for GPG to encrypt archives
diff --git a/pom.xml b/pom.xml
index fd0fe81af9..c55d5297aa 100644
--- a/pom.xml
+++ b/pom.xml
@@ -1082,9 +1082,9 @@
 					<testCasesDirectory>${basedir}/src/test/robotframework</testCasesDirectory>
 					<xunitFile>NONE</xunitFile>
 					<randomize>suite</randomize>
-					<!-- See http://robotframework.org/robotframework/3.1.2/RobotFrameworkUserGuide.html#controlling-console-output -->
+					<!-- See https://robotframework.org/robotframework/3.1.2/RobotFrameworkUserGuide.html#controlling-console-output -->
 					<console>dotted</console>
-					<!-- See http://robotframework.org/robotframework/3.1.2/RobotFrameworkUserGuide.html#removing-keywords -->
+					<!-- See https://robotframework.org/robotframework/3.1.2/RobotFrameworkUserGuide.html#removing-keywords -->
 					<removeKeywords>PASSED</removeKeywords>
 					<!-- Handy for debugging. Log file will be created in target/ directory -->
 					<!--
@@ -1207,7 +1207,7 @@
 	<licenses>
 		<license>
 			<name>GNU GPL v2</name>
-			<url>http://www.gnu.org/licenses/gpl-2.0.html</url>
+			<url>https://www.gnu.org/licenses/old-licenses/gpl-2.0.html</url>
 			<distribution>repo</distribution>
 		</license>
 	</licenses>
diff --git a/src/main/config/checkstyle.xml b/src/main/config/checkstyle.xml
index 8cf0117a17..2c4eb99f79 100644
--- a/src/main/config/checkstyle.xml
+++ b/src/main/config/checkstyle.xml
@@ -20,7 +20,7 @@
     - some best practices
 
   Checkstyle is very configurable. Be sure to read the documentation at
-  http://checkstyle.sourceforge.net (or in your downloaded distribution).
+  https://checkstyle.sourceforge.io (or in your downloaded distribution).
 
   Most Checks are configurable, be sure to consult the documentation.
 
@@ -34,17 +34,17 @@
     <!--
         If you set the basedir property below, then all reported file
         names will be relative to the specified directory. See
-        http://checkstyle.sourceforge.net/config.html#Checker
+        https://checkstyle.sourceforge.io/config.html#Checker
 
         <property name="basedir" value="${basedir}"/>
     -->
 
     <!-- Checks that each Java package has a Javadoc file used for commenting.    -->
-    <!-- See http://checkstyle.sourceforge.net/config_javadoc.html#JavadocPackage -->
+    <!-- See https://checkstyle.sourceforge.io/config_javadoc.html#JavadocPackage -->
     <module name="JavadocPackage" />
 
     <!-- Checks whether files end with a new line.                                 -->
-    <!-- See http://checkstyle.sourceforge.net/config_misc.html#NewlineAtEndOfFile -->
+    <!-- See https://checkstyle.sourceforge.io/config_misc.html#NewlineAtEndOfFile -->
     <module name="NewlineAtEndOfFile">
         <property name="severity" value="warning"/>
         <!--
@@ -55,7 +55,7 @@
     </module>
 
     <!-- Checks that property files contain the same keys.                  -->
-    <!-- See http://checkstyle.sourceforge.net/config_misc.html#Translation -->
+    <!-- See https://checkstyle.sourceforge.io/config_misc.html#Translation -->
     <module name="Translation"/>
 
     <module name="FileLength"/>
@@ -98,7 +98,7 @@
         <module name="SuppressWarningsHolder"/>
 
         <!-- Checks for Javadoc comments.                              -->
-        <!-- See http://checkstyle.sourceforge.net/config_javadoc.html -->
+        <!-- See https://checkstyle.sourceforge.io/config_javadoc.html -->
         <!--
             <module name="JavadocMethod"/>
             <module name="JavadocType"/>
@@ -108,7 +108,7 @@
 
 
         <!-- Checks for Naming Conventions.                           -->
-        <!-- See http://checkstyle.sourceforge.net/config_naming.html -->
+        <!-- See https://checkstyle.sourceforge.io/config_naming.html -->
         <module name="AbstractClassName"/>
         <module name="ConstantName"/>
         <module name="LocalFinalVariableName"/>
@@ -122,14 +122,14 @@
 
 
         <!-- Checks for Headers                                           -->
-        <!-- See http://checkstyle.sourceforge.net/config_header.html     -->
+        <!-- See https://checkstyle.sourceforge.io/config_header.html     -->
         <!-- <module name="Header">                                       -->
             <!-- The follow property value demonstrates the ability       -->
             <!-- to have access to ANT properties. In this case it uses   -->
             <!-- the ${basedir} property to allow Checkstyle to be run    -->
             <!-- from any directory within a project. See property        -->
             <!-- expansion,                                               -->
-            <!-- http://checkstyle.sourceforge.net/config.html#Properties -->
+            <!-- https://checkstyle.sourceforge.io/config.html#Properties -->
             <!-- <property                                                -->
             <!--     name="headerFile"                                    -->
             <!--     value="${basedir}/java.header"/>                     -->
@@ -137,7 +137,7 @@
 
 
         <!-- Checks for imports                                        -->
-        <!-- See http://checkstyle.sourceforge.net/config_imports.html -->
+        <!-- See https://checkstyle.sourceforge.io/config_imports.html -->
         <module name="AvoidStarImport"/>
         <module name="IllegalImport"> <!-- defaults to sun.* packages -->
             <property name="illegalPkgs" value="org.apache.log4j, org.apache.commons.lang"/>
@@ -153,7 +153,7 @@
 
 
         <!-- Checks for Size Violations.                             -->
-        <!-- See http://checkstyle.sourceforge.net/config_sizes.html -->
+        <!-- See https://checkstyle.sourceforge.io/config_sizes.html -->
         <module name="LineLength">
             <property name="severity" value="warning"/>
             <property name="max" value="100"/>
@@ -164,7 +164,7 @@
 
 
         <!-- Checks for whitespace                                        -->
-        <!-- See http://checkstyle.sourceforge.net/config_whitespace.html -->
+        <!-- See https://checkstyle.sourceforge.io/config_whitespace.html -->
         <module name="EmptyForIteratorPad"/>
         <module name="MethodParamPad"/>
         <module name="NoWhitespaceAfter">
@@ -186,13 +186,13 @@
 
 
         <!-- Modifier Checks                                            -->
-        <!-- See http://checkstyle.sourceforge.net/config_modifier.html -->
+        <!-- See https://checkstyle.sourceforge.io/config_modifier.html -->
         <module name="ModifierOrder"/>
         <module name="RedundantModifier"/>
 
 
         <!-- Checks for blocks. You know, those {}'s                  -->
-        <!-- See http://checkstyle.sourceforge.net/config_blocks.html -->
+        <!-- See https://checkstyle.sourceforge.io/config_blocks.html -->
         <module name="AvoidNestedBlocks"/>
         <module name="EmptyBlock"/>
         <module name="LeftCurly"/>
@@ -201,7 +201,7 @@
 
 
         <!-- Checks for common coding problems                        -->
-        <!-- See http://checkstyle.sourceforge.net/config_coding.html -->
+        <!-- See https://checkstyle.sourceforge.io/config_coding.html -->
 	<!--
         <module name="AvoidInlineConditionals"/>
 	-->
@@ -233,7 +233,7 @@
         -->
 
         <!-- Checks for class design                                  -->
-        <!-- See http://checkstyle.sourceforge.net/config_design.html -->
+        <!-- See https://checkstyle.sourceforge.io/config_design.html -->
         <!--
             <module name="DesignForExtension"/>
         -->
@@ -246,7 +246,7 @@
 
 
         <!-- Miscellaneous other checks.                            -->
-        <!-- See http://checkstyle.sourceforge.net/config_misc.html -->
+        <!-- See https://checkstyle.sourceforge.io/config_misc.html -->
         <module name="ArrayTypeStyle"/>
         <!--
         <module name="FinalParameters">
diff --git a/src/main/config/pmd.xml b/src/main/config/pmd.xml
index 83722e6e0e..a86742377b 100644
--- a/src/main/config/pmd.xml
+++ b/src/main/config/pmd.xml
@@ -110,8 +110,8 @@
 	<rule ref="category/java/codestyle.xml/ShortMethodName" />
 	<!--
 		See also:
-		- http://sourceforge.net/p/pmd/bugs/951/
-		- http://sourceforge.net/p/pmd/feature-requests/546/
+		- https://sourceforge.net/p/pmd/bugs/951/
+		- https://sourceforge.net/p/pmd/bugs/1361/
 	-->
 	<!--<rule ref="category/java/codestyle.xml/ShortVariable" />-->
 	<rule ref="category/java/codestyle.xml/SuspiciousConstantFieldName" />
diff --git a/src/main/java/ru/mystamps/web/common/JdbcUtils.java b/src/main/java/ru/mystamps/web/common/JdbcUtils.java
index a01cdfe549..77f852dfbf 100644
--- a/src/main/java/ru/mystamps/web/common/JdbcUtils.java
+++ b/src/main/java/ru/mystamps/web/common/JdbcUtils.java
@@ -27,7 +27,7 @@ public final class JdbcUtils {
 	private JdbcUtils() {
 	}
 	
-	// @see http://stackoverflow.com/q/2920364/checking-for-a-null-int-value-from-a-java-resultset
+	// @see https://stackoverflow.com/q/2920364/checking-for-a-null-int-value-from-a-java-resultset
 	@SuppressWarnings("PMD.PrematureDeclaration")
 	public static Integer getInteger(ResultSet resultSet, String fieldName) throws SQLException {
 		int value = resultSet.getInt(fieldName);
diff --git a/src/main/java/ru/mystamps/web/feature/account/AccountValidation.java b/src/main/java/ru/mystamps/web/feature/account/AccountValidation.java
index ec9ce0e1e3..7ac97d1c17 100644
--- a/src/main/java/ru/mystamps/web/feature/account/AccountValidation.java
+++ b/src/main/java/ru/mystamps/web/feature/account/AccountValidation.java
@@ -35,7 +35,7 @@ public final class AccountValidation {
 	
 	static final int PASSWORD_MIN_LENGTH = 4;
 	// We limit max length because bcrypt has a maximum password length.
-	// See also: http://www.mscharhag.com/software-development/bcrypt-maximum-password-length
+	// See also: https://www.mscharhag.com/software-development/bcrypt-maximum-password-length
 	static final int PASSWORD_MAX_LENGTH = 72;
 	
 	static final int EMAIL_MAX_LENGTH = UsersActivation.EMAIL_LENGTH;
diff --git a/src/main/java/ru/mystamps/web/support/beanvalidation/package-info.java b/src/main/java/ru/mystamps/web/support/beanvalidation/package-info.java
index 6547dd3bc7..c6103ac5ed 100644
--- a/src/main/java/ru/mystamps/web/support/beanvalidation/package-info.java
+++ b/src/main/java/ru/mystamps/web/support/beanvalidation/package-info.java
@@ -1,5 +1,5 @@
 /**
- * Implementations of the custom <a href="http://beanvalidation.org/1.0/spec/"
+ * Implementations of the custom <a href="https://beanvalidation.org/1.0/spec/"
  * target="_blank">JSR-303</a> compatible validators.
  */
 package ru.mystamps.web.support.beanvalidation;
diff --git a/src/main/java/ru/mystamps/web/support/togglz/TogglzConfig.java b/src/main/java/ru/mystamps/web/support/togglz/TogglzConfig.java
index 819f0a8ca8..c18acecc7b 100644
--- a/src/main/java/ru/mystamps/web/support/togglz/TogglzConfig.java
+++ b/src/main/java/ru/mystamps/web/support/togglz/TogglzConfig.java
@@ -61,7 +61,7 @@ public FeatureManager getFeatureManager() {
 	 *
 	 * Access it via http://127.0.0.1:8080/togglz after authentication as "admin" user.
 	 *
-	 * @see http://www.togglz.org/documentation/admin-console.html
+	 * @see https://www.togglz.org/documentation/admin-console.html
 	 */
 	@Bean
 	public ServletRegistrationBean getTogglzConsole() {
diff --git a/src/main/resources/liquibase/version/0.4.3/2020-03-07--site_parser_params_value_length.xml b/src/main/resources/liquibase/version/0.4.3/2020-03-07--site_parser_params_value_length.xml
index e675cd8514..053082361d 100644
--- a/src/main/resources/liquibase/version/0.4.3/2020-03-07--site_parser_params_value_length.xml
+++ b/src/main/resources/liquibase/version/0.4.3/2020-03-07--site_parser_params_value_length.xml
@@ -13,7 +13,7 @@
 		
 		<!--
 			modifyDataType loses NOT NULL property on MySQL:
-			http://forum.liquibase.org/topic/warning-of-losing-primary-key-autoincrement-for-mysql
+			https://forum.liquibase.org/topic/warning-of-losing-primary-key-autoincrement-for-mysql
 			In order to fix that, we patch the SQL query to specify NOT NULL again.
 		-->
 		<modifySql dbms="mysql">
diff --git a/src/main/resources/liquibase/version/0.4.3/2020-03-12--michel_catalog_code_length.xml b/src/main/resources/liquibase/version/0.4.3/2020-03-12--michel_catalog_code_length.xml
index 8d581f72f1..63fcbb6dff 100644
--- a/src/main/resources/liquibase/version/0.4.3/2020-03-12--michel_catalog_code_length.xml
+++ b/src/main/resources/liquibase/version/0.4.3/2020-03-12--michel_catalog_code_length.xml
@@ -13,7 +13,7 @@
 
 		<!--
 			modifyDataType loses NOT NULL property on MySQL:
-			http://forum.liquibase.org/topic/warning-of-losing-primary-key-autoincrement-for-mysql
+			https://forum.liquibase.org/topic/warning-of-losing-primary-key-autoincrement-for-mysql
 			In order to fix that, we patch the SQL query to specify NOT NULL again.
 		-->
 		<modifySql dbms="mysql">
diff --git a/src/main/resources/liquibase/version/0.4/2015-07-07--salt_and_hash.xml b/src/main/resources/liquibase/version/0.4/2015-07-07--salt_and_hash.xml
index 5be5cc7fc9..016e9bd4cd 100644
--- a/src/main/resources/liquibase/version/0.4/2015-07-07--salt_and_hash.xml
+++ b/src/main/resources/liquibase/version/0.4/2015-07-07--salt_and_hash.xml
@@ -17,7 +17,7 @@
 		
 		<!--
 			We can't use modifyDataType because it looses not null setting:
-			http://forum.liquibase.org/topic/warning-of-losing-primary-key-autoincrement-for-mysql
+			https://forum.liquibase.org/topic/warning-of-losing-primary-key-autoincrement-for-mysql
 		-->
 		<sql>
 			ALTER TABLE users
diff --git a/src/main/resources/liquibase/version/0.4/2016-01-02--non_unique_catalog_numbers.xml b/src/main/resources/liquibase/version/0.4/2016-01-02--non_unique_catalog_numbers.xml
index cdb2953552..e305b5e3b7 100644
--- a/src/main/resources/liquibase/version/0.4/2016-01-02--non_unique_catalog_numbers.xml
+++ b/src/main/resources/liquibase/version/0.4/2016-01-02--non_unique_catalog_numbers.xml
@@ -5,7 +5,7 @@
 		xsi:schemaLocation="http://www.liquibase.org/xml/ns/dbchangelog
 		http://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-3.0.xsd">
 	
-	<!-- Workaround for http://www.xaprb.com/blog/2006/08/22/mysqls-error-1025-explained/ -->
+	<!-- Workaround for https://www.xaprb.com/blog/2006/08/22/mysqls-error-1025-explained/ -->
 	<changeSet id="temporary-drop-catalog-numbers-foreign-keys" author="php-coder" context="scheme">
 		
 		<dropForeignKeyConstraint
diff --git a/src/main/scripts/ci/deploy.sh b/src/main/scripts/ci/deploy.sh
index f4ad24507e..c22934a72e 100755
--- a/src/main/scripts/ci/deploy.sh
+++ b/src/main/scripts/ci/deploy.sh
@@ -22,7 +22,7 @@ cleanup() {
 trap 'cleanup' EXIT SIGHUP SIGINT SIGTERM
 
 # Disable host key checking to suppress interactive prompt.
-# See: http://docs.ansible.com/ansible/intro_getting_started.html#host-key-checking
+# See: https://docs.ansible.com/ansible/2.9/user_guide/connection_details.html#host-key-checking
 export ANSIBLE_HOST_KEY_CHECKING=False
 
 if [ -z "${encrypted_bf07cb25089f_key:-}" ] || [ -z "${encrypted_bf07cb25089f_iv:-}" ] ; then
diff --git a/src/main/webapp/WEB-INF/static/styles/main.css b/src/main/webapp/WEB-INF/static/styles/main.css
index 9548a2b2de..8cff9eee05 100644
--- a/src/main/webapp/WEB-INF/static/styles/main.css
+++ b/src/main/webapp/WEB-INF/static/styles/main.css
@@ -91,7 +91,7 @@ label {
 	margin-bottom: 10px;
 }
 
-/* http://stackoverflow.com/questions/20547819/vertical-align-with-bootstrap-3 */
+/* https://stackoverflow.com/questions/20547819/vertical-align-with-bootstrap-3 */
 .vcenter {
 	display: inline-block;
 	vertical-align: middle;