diff --git a/TODO b/TODO
index ddfde125..202fae28 100644
--- a/TODO
+++ b/TODO
@@ -3,7 +3,6 @@ first major release.
 
 everything related to posts:
     - single post view
-        - fav
         - score
         - editing
             - ability to loop video posts
@@ -104,8 +103,6 @@ refactors:
       with query decorated by PostDao::decorateQueryFromFilter, call
       PostDao::decorateEntitiesWithFilter that will optimally load users and
       inject them using posts' lazy loaders.
-    - make view proxies less greedy, e.g. favs should be fetched only in post
-      view, not for each of 40 posts in post list. (same goes to other things)
     - reduce dependencies
 
 miscellaneous:
diff --git a/public_html/css/post.css b/public_html/css/post.css
index f2a4d37c..863000db 100644
--- a/public_html/css/post.css
+++ b/public_html/css/post.css
@@ -56,6 +56,10 @@
 	}
 }
 
+#post-view-wrapper .favorites li {
+	display: inline-block;
+	margin: 0 0.25em 0.25em 0;
+}
 
 #sidebar ul {
 	list-style-type: none;
diff --git a/public_html/js/Presenters/PostPresenter.js b/public_html/js/Presenters/PostPresenter.js
index 99971d8d..341722ef 100644
--- a/public_html/js/Presenters/PostPresenter.js
+++ b/public_html/js/Presenters/PostPresenter.js
@@ -22,6 +22,7 @@ App.Presenters.PostPresenter = function(
 	var historyTemplate;
 
 	var post;
+	var postFavorites;
 	var postHistory;
 	var postNameOrId;
 
@@ -74,11 +75,16 @@ App.Presenters.PostPresenter = function(
 
 		promise.waitAll(
 				api.get('/posts/' + postNameOrId),
+				api.get('/posts/' + postNameOrId + '/favorites'),
 				privileges.canViewHistory ?
 					api.get('/posts/' + postNameOrId + '/history') :
 					null)
-			.then(function(postResponse, postHistoryResponse) {
+			.then(function(
+					postResponse,
+					postFavoritesResponse,
+					postHistoryResponse) {
 				post = postResponse.json;
+				postFavorites = postFavoritesResponse && postFavoritesResponse.json && postFavoritesResponse.json.data;
 				postHistory = postHistoryResponse && postHistoryResponse.json && postHistoryResponse.json.data;
 				topNavigationPresenter.changeTitle('@' + post.id);
 				render();
@@ -112,30 +118,43 @@ App.Presenters.PostPresenter = function(
 		}
 
 		$el.find('.post-edit-wrapper form').submit(editFormSubmitted);
-		$el.find('#sidebar .delete').click(deleteButtonClicked);
-		$el.find('#sidebar .feature').click(featureButtonClicked);
-		$el.find('#sidebar .edit').click(editButtonClicked);
-		$el.find('#sidebar .history').click(historyButtonClicked);
+		attachSidebarEvents();
 	}
 
 	function renderSidebar() {
 		$el.find('#sidebar').html(jQuery(renderPostTemplate()).find('#sidebar').html());
+		attachSidebarEvents();
 	}
 
 	function renderPostTemplate() {
 		return postTemplate({
 			post: post,
+			postFavorites: postFavorites,
 			postHistory: postHistory,
+
 			formatRelativeTime: util.formatRelativeTime,
 			formatFileSize: util.formatFileSize,
+
 			postContentTemplate: postContentTemplate,
 			postEditTemplate: postEditTemplate,
 			historyTemplate: historyTemplate,
+
+			hasFav: _.any(postFavorites, function(favUser) { return favUser.id === auth.getCurrentUser().id; }),
+			isLoggedIn: auth.isLoggedIn(),
 			privileges: privileges,
 			editPrivileges: editPrivileges,
 		});
 	}
 
+	function attachSidebarEvents() {
+		$el.find('#sidebar .delete').click(deleteButtonClicked);
+		$el.find('#sidebar .feature').click(featureButtonClicked);
+		$el.find('#sidebar .edit').click(editButtonClicked);
+		$el.find('#sidebar .history').click(historyButtonClicked);
+		$el.find('#sidebar .add-favorite').click(addFavoriteButtonClicked);
+		$el.find('#sidebar .delete-favorite').click(deleteFavoriteButtonClicked);
+	}
+
 	function deleteButtonClicked(e) {
 		e.preventDefault();
 		messagePresenter.hideMessages($messages);
@@ -268,6 +287,34 @@ App.Presenters.PostPresenter = function(
 		$el.find('.post-history-wrapper').slideDown('slow');
 	}
 
+	function addFavoriteButtonClicked(e) {
+		e.preventDefault();
+		addFavorite();
+	}
+
+	function deleteFavoriteButtonClicked(e) {
+		e.preventDefault();
+		deleteFavorite();
+	}
+
+	function addFavorite() {
+		api.post('/posts/' + post.id + '/favorites')
+			.then(function(response) {
+				postFavorites = response.json.data;
+				renderSidebar();
+			})
+			.fail(showGenericError);
+	}
+
+	function deleteFavorite() {
+		api.delete('/posts/' + post.id + '/favorites')
+			.then(function(response) {
+				postFavorites = response.json.data;
+				renderSidebar();
+			})
+			.fail(showGenericError);
+	}
+
 	function showEditError(response) {
 		window.alert(response.json && response.json.error || response);
 	}
diff --git a/public_html/templates/post.tpl b/public_html/templates/post.tpl
index 1bb3156c..f1eb1372 100644
--- a/public_html/templates/post.tpl
+++ b/public_html/templates/post.tpl
@@ -10,6 +10,20 @@
 					<%= post.contentExtension + ', ' + formatFileSize(post.originalFileSize) %>
 				</a>
 			</li>
+
+			<% if (isLoggedIn) { %>
+				<li>
+					<% if (hasFav) { %>
+						<a href="#" class="delete-favorite">
+							<i class="fa fa-heart"></i>
+						</a>
+					<% } else { %>
+						<a href="#" class="add-favorite">
+							<i class="fa fa-heart-o"></i>
+						</a>
+					<% } %>
+				</li>
+			<% } %>
 		</ul>
 
 		<h1>Tags (<%= _.size(post.tags) %>)</h1>
@@ -98,9 +112,24 @@
 					--><% } %><!--
 				--></li>
 			<% } %>
-
 		</ul>
 
+		<% if (_.any(postFavorites)) { %>
+			<p>Favorites:</p>
+
+			<ul class="favorites">
+				<% _.each(postFavorites, function(user) { %>
+					<li>
+						<a href="#/user/<%= user.name %>">
+							<img class="fav-avatar"
+								src="/data/thumbnails/25x25/avatars/<%= user.name || '!' %>"
+								alt="<%= user.name || 'Anonymous user' %>"/>
+						</a>
+					</li>
+				<% }) %>
+			</ul>
+		<% } %>
+
 		<% if (_.any(post.relations)) { %>
 			<h1>Related posts</h1>
 			<ul class="related">
diff --git a/src/Controllers/FavoritesController.php b/src/Controllers/FavoritesController.php
new file mode 100644
index 00000000..9791e5af
--- /dev/null
+++ b/src/Controllers/FavoritesController.php
@@ -0,0 +1,57 @@
+<?php
+namespace Szurubooru\Controllers;
+
+class FavoritesController extends AbstractController
+{
+	private $privilegeService;
+	private $authService;
+	private $postService;
+	private $favoritesService;
+	private $userViewProxy;
+
+	public function __construct(
+		\Szurubooru\Services\PrivilegeService $privilegeService,
+		\Szurubooru\Services\AuthService $authService,
+		\Szurubooru\Services\PostService $postService,
+		\Szurubooru\Services\FavoritesService $favoritesService,
+		\Szurubooru\Controllers\ViewProxies\UserViewProxy $userViewProxy)
+	{
+		$this->privilegeService = $privilegeService;
+		$this->authService = $authService;
+		$this->postService = $postService;
+		$this->favoritesService = $favoritesService;
+		$this->userViewProxy = $userViewProxy;
+	}
+
+	public function registerRoutes(\Szurubooru\Router $router)
+	{
+		$router->get('/api/posts/:postNameOrId/favorites', [$this, 'getFavoriteUsers']);
+		$router->post('/api/posts/:postNameOrId/favorites', [$this, 'addFavorite']);
+		$router->delete('/api/posts/:postNameOrId/favorites', [$this, 'deleteFavorite']);
+	}
+
+	public function getFavoriteUsers($postNameOrId)
+	{
+		$post = $this->postService->getByNameOrId($postNameOrId);
+		$users = $this->favoritesService->getFavoriteUsers($post);
+		return ['data' => $this->userViewProxy->fromArray($users)];
+	}
+
+	public function addFavorite($postNameOrId)
+	{
+		$this->privilegeService->assertLoggedIn();
+		$user = $this->authService->getLoggedInUser();
+		$post = $this->postService->getByNameOrId($postNameOrId);
+		$this->favoritesService->addFavorite($user, $post);
+		return $this->getFavoriteUsers($postNameOrId);
+	}
+
+	public function deleteFavorite($postNameOrId)
+	{
+		$this->privilegeService->assertLoggedIn();
+		$user = $this->authService->getLoggedInUser();
+		$post = $this->postService->getByNameOrId($postNameOrId);
+		$this->favoritesService->deleteFavorite($user, $post);
+		return $this->getFavoriteUsers($postNameOrId);
+	}
+}
diff --git a/src/Dao/AbstractDao.php b/src/Dao/AbstractDao.php
index bf583281..94c7e6f8 100644
--- a/src/Dao/AbstractDao.php
+++ b/src/Dao/AbstractDao.php
@@ -133,14 +133,9 @@ abstract class AbstractDao implements ICrudDao
 
 	protected function findBy($columnName, $value)
 	{
-		$entities = [];
 		$query = $this->fpdo->from($this->tableName)->where($columnName, $value);
-		foreach ($query as $arrayEntity)
-		{
-			$entity = $this->entityConverter->toEntity($arrayEntity);
-			$entities[$entity->getId()] = $entity;
-		}
-		return $entities;
+		$arrayEntities = iterator_to_array($query);
+		return $this->arrayToEntities($arrayEntities);
 	}
 
 	protected function findOneBy($columnName, $value)
diff --git a/src/Dao/EntityConverters/FavoriteEntityConverter.php b/src/Dao/EntityConverters/FavoriteEntityConverter.php
new file mode 100644
index 00000000..41522ba4
--- /dev/null
+++ b/src/Dao/EntityConverters/FavoriteEntityConverter.php
@@ -0,0 +1,23 @@
+<?php
+namespace Szurubooru\Dao\EntityConverters;
+
+class FavoriteEntityConverter extends AbstractEntityConverter implements IEntityConverter
+{
+	public function toArray(\Szurubooru\Entities\Entity $entity)
+	{
+		return
+		[
+			'id' => $entity->getId(),
+			'userId' => $entity->getUserId(),
+			'postId' => $entity->getPostId(),
+		];
+	}
+
+	public function toBasicEntity(array $array)
+	{
+		$entity = new \Szurubooru\Entities\Favorite($array['id']);
+		$entity->setUserId($array['userId']);
+		$entity->setPostId($array['postId']);
+		return $entity;
+	}
+}
diff --git a/src/Dao/EntityConverters/PostEntityConverter.php b/src/Dao/EntityConverters/PostEntityConverter.php
index 108b2da1..d84fc166 100644
--- a/src/Dao/EntityConverters/PostEntityConverter.php
+++ b/src/Dao/EntityConverters/PostEntityConverter.php
@@ -45,6 +45,7 @@ class PostEntityConverter extends AbstractEntityConverter implements IEntityConv
 		$entity->setFeatureCount(intval($array['featureCount']));
 		$entity->setLastFeatureTime($array['lastFeatureTime']);
 		$entity->setMeta(\Szurubooru\Entities\Post::META_TAG_COUNT, intval($array['tagCount']));
+		$entity->setMeta(\Szurubooru\Entities\Post::META_FAV_COUNT, intval($array['favCount']));
 		return $entity;
 	}
 }
diff --git a/src/Dao/FavoritesDao.php b/src/Dao/FavoritesDao.php
new file mode 100644
index 00000000..f07ec235
--- /dev/null
+++ b/src/Dao/FavoritesDao.php
@@ -0,0 +1,54 @@
+<?php
+namespace Szurubooru\Dao;
+
+class FavoritesDao extends AbstractDao implements ICrudDao
+{
+	private $userDao;
+	private $postDao;
+
+	public function __construct(
+		\Szurubooru\DatabaseConnection $databaseConnection,
+		\Szurubooru\Dao\UserDao $userDao,
+		\Szurubooru\Dao\PostDao $postDao)
+	{
+		parent::__construct(
+			$databaseConnection,
+			'favorites',
+			new \Szurubooru\Dao\EntityConverters\FavoriteEntityConverter());
+
+		$this->userDao = $userDao;
+		$this->postDao = $postDao;
+	}
+
+	public function findByUserAndPost(\Szurubooru\Entities\User $user, \Szurubooru\Entities\Post $post)
+	{
+		$query = $this->fpdo->from($this->tableName)
+			->where('userId', $user->getId())
+			->where('postId', $post->getId());
+		$arrayEntities = iterator_to_array($query);
+		$entities = $this->arrayToEntities($arrayEntities);
+		return array_shift($entities);
+	}
+
+	public function findByPost(\Szurubooru\Entities\Post $post)
+	{
+		return $this->findBy('postId', $post->getId());
+	}
+
+	protected function afterLoad(\Szurubooru\Entities\Entity $favorite)
+	{
+		$favorite->setLazyLoader(
+			\Szurubooru\Entities\Favorite::LAZY_LOADER_USER,
+			function (\Szurubooru\Entities\Favorite $favorite)
+			{
+				return $this->userDao->findById($favorite->getUserId());
+			});
+
+		$favorite->setLazyLoader(
+			\Szurubooru\Entities\Favorite::LAZY_LOADER_POST,
+			function (\Szurubooru\Entities\Favorite $favorite)
+			{
+				return $this->postDao->findById($favorite->getPostId());
+			});
+	}
+}
diff --git a/src/Dao/PostDao.php b/src/Dao/PostDao.php
index 2aee3f49..1dfec15b 100644
--- a/src/Dao/PostDao.php
+++ b/src/Dao/PostDao.php
@@ -51,35 +51,35 @@ class PostDao extends AbstractDao implements ICrudDao
 	{
 		$post->setLazyLoader(
 			\Szurubooru\Entities\Post::LAZY_LOADER_CONTENT,
-			function(\Szurubooru\Entities\Post $post)
+			function (\Szurubooru\Entities\Post $post)
 			{
 				return $this->fileService->load($post->getContentPath());
 			});
 
 		$post->setLazyLoader(
 			\Szurubooru\Entities\Post::LAZY_LOADER_THUMBNAIL_SOURCE_CONTENT,
-			function(\Szurubooru\Entities\Post $post)
+			function (\Szurubooru\Entities\Post $post)
 			{
 				return $this->fileService->load($post->getThumbnailSourceContentPath());
 			});
 
 		$post->setLazyLoader(
 			\Szurubooru\Entities\Post::LAZY_LOADER_USER,
-			function(\Szurubooru\Entities\Post $post)
+			function (\Szurubooru\Entities\Post $post)
 			{
 				return $this->getUser($post);
 			});
 
 		$post->setLazyLoader(
 			\Szurubooru\Entities\Post::LAZY_LOADER_TAGS,
-			function(\Szurubooru\Entities\Post $post)
+			function (\Szurubooru\Entities\Post $post)
 			{
 				return $this->getTags($post);
 			});
 
 		$post->setLazyLoader(
 			\Szurubooru\Entities\Post::LAZY_LOADER_RELATED_POSTS,
-			function(\Szurubooru\Entities\Post $post)
+			function (\Szurubooru\Entities\Post $post)
 			{
 				return $this->getRelatedPosts($post);
 			});
@@ -179,14 +179,14 @@ class PostDao extends AbstractDao implements ICrudDao
 		$this->tagDao->createMissingTags($tagNames);
 
 		$tagIds = array_map(
-			function($tag)
+			function ($tag)
 			{
 				return $tag->getId();
 			},
 			$this->tagDao->findByNames($tagNames));
 
 		$existingTagRelationIds = array_map(
-			function($arrayEntity)
+			function ($arrayEntity)
 			{
 				return $arrayEntity['tagId'];
 			},
diff --git a/src/Entities/Entity.php b/src/Entities/Entity.php
index e31cab4c..5d6116f9 100644
--- a/src/Entities/Entity.php
+++ b/src/Entities/Entity.php
@@ -43,6 +43,7 @@ abstract class Entity
 	public function resetLazyLoaders()
 	{
 		$this->lazyLoaders = [];
+		$this->lazyContainers = [];
 	}
 
 	public function setLazyLoader($lazyContainerName, $getter)
diff --git a/src/Entities/Favorite.php b/src/Entities/Favorite.php
new file mode 100644
index 00000000..af9f0421
--- /dev/null
+++ b/src/Entities/Favorite.php
@@ -0,0 +1,53 @@
+<?php
+namespace Szurubooru\Entities;
+
+class Favorite extends Entity
+{
+	private $postId;
+	private $userId;
+
+	const LAZY_LOADER_USER = 'user';
+	const LAZY_LOADER_POST = 'post';
+
+	public function getUserId()
+	{
+		return $this->userId;
+	}
+
+	public function setUserId($userId)
+	{
+		$this->userId = $userId;
+	}
+
+	public function getPostId()
+	{
+		return $this->postId;
+	}
+
+	public function setPostId($postId)
+	{
+		$this->postId = $postId;
+	}
+
+	public function getUser()
+	{
+		return $this->lazyLoad(self::LAZY_LOADER_USER, null);
+	}
+
+	public function setUser(\Szurubooru\Entities\User $user)
+	{
+		$this->lazySave(self::LAZY_LOADER_USER, $user);
+		$this->userId = $user->getId();
+	}
+
+	public function getPost()
+	{
+		return $this->lazyLoad(self::LAZY_LOADER_POST, null);
+	}
+
+	public function setPost(\Szurubooru\Entities\Post $post)
+	{
+		$this->lazySave(self::LAZY_LOADER_POST, $post);
+		$this->postId = $post->getId();
+	}
+}
diff --git a/src/Entities/Post.php b/src/Entities/Post.php
index a636b3df..1d4e513c 100644
--- a/src/Entities/Post.php
+++ b/src/Entities/Post.php
@@ -19,6 +19,7 @@ final class Post extends Entity
 	const LAZY_LOADER_RELATED_POSTS = 'relatedPosts';
 
 	const META_TAG_COUNT = 'tagCount';
+	const META_FAV_COUNT = 'favCount';
 
 	protected $name;
 	protected $userId;
@@ -257,4 +258,9 @@ final class Post extends Entity
 	{
 		return $this->getMeta(self::META_TAG_COUNT, 0);
 	}
+
+	public function getFavoriteCount()
+	{
+		return $this->getMeta(self::META_FAV_COUNT, 0);
+	}
 }
diff --git a/src/Services/FavoritesService.php b/src/Services/FavoritesService.php
new file mode 100644
index 00000000..c8ccdae1
--- /dev/null
+++ b/src/Services/FavoritesService.php
@@ -0,0 +1,60 @@
+<?php
+namespace Szurubooru\Services;
+
+class FavoritesService
+{
+	private $favoritesDao;
+	private $userDao;
+	private $transactionManager;
+
+	public function __construct(
+		\Szurubooru\Dao\FavoritesDao $favoritesDao,
+		\Szurubooru\Dao\UserDao $userDao,
+		\Szurubooru\Dao\TransactionManager $transactionManager)
+	{
+		$this->favoritesDao = $favoritesDao;
+		$this->userDao = $userDao;
+		$this->transactionManager = $transactionManager;
+	}
+
+	public function getFavoriteUsers(\Szurubooru\Entities\Post $post)
+	{
+		$transactionFunc = function() use ($post)
+		{
+			$favorites = $this->favoritesDao->findByPost($post);
+			$userIds = [];
+			foreach ($favorites as $favorite)
+			{
+				$userIds[] = $favorite->getUserId();
+			}
+			return $this->userDao->findByIds($userIds);
+		};
+		return $this->transactionManager->rollback($transactionFunc);
+	}
+
+	public function addFavorite(\Szurubooru\Entities\User $user, \Szurubooru\Entities\Post $post)
+	{
+		$transactionFunc = function() use ($user, $post)
+		{
+			$favorite = $this->favoritesDao->findByUserAndPost($user, $post);
+			if (!$favorite)
+			{
+				$favorite = new \Szurubooru\Entities\Favorite();
+				$favorite->setUser($user);
+				$favorite->setPost($post);
+				$this->favoritesDao->save($favorite);
+			}
+		};
+		return $this->transactionManager->commit($transactionFunc);
+	}
+
+	public function deleteFavorite(\Szurubooru\Entities\User $user, \Szurubooru\Entities\Post $post)
+	{
+		$transactionFunc = function() use ($user, $post)
+		{
+			$favorite = $this->favoritesDao->findByUserAndPost($user, $post);
+			$this->favoritesDao->deleteById($favorite->getId());
+		};
+		return $this->transactionManager->commit($transactionFunc);
+	}
+}
diff --git a/src/Services/PrivilegeService.php b/src/Services/PrivilegeService.php
index 90017fa7..7cd43de3 100644
--- a/src/Services/PrivilegeService.php
+++ b/src/Services/PrivilegeService.php
@@ -44,13 +44,21 @@ class PrivilegeService
 	public function assertPrivilege($privilege)
 	{
 		if (!$this->hasPrivilege($privilege))
-			throw new \DomainException('Unprivileged operation');
+			$this->fail();
 	}
 
-	public function assertLoggedIn($userIdentifier)
+	public function assertLoggedIn($userIdentifier = null)
 	{
-		if (!$this->isLoggedIn($userIdentifier))
-			throw new \DomainException('Unprivileged operation');
+		if ($userIdentifier)
+		{
+			if (!$this->isLoggedIn($userIdentifier))
+				$this->fail();
+		}
+		else
+		{
+			if (!$this->authService->getLoggedInUser())
+				$this->fail();
+		}
 	}
 
 	public function isLoggedIn($userIdentifier)
@@ -74,4 +82,9 @@ class PrivilegeService
 			throw new \InvalidArgumentException('Invalid user identifier.');
 		}
 	}
+
+	private function fail()
+	{
+		throw new \DomainException('Unprivileged operation');
+	}
 }
diff --git a/src/Upgrades/Upgrade10.php b/src/Upgrades/Upgrade10.php
new file mode 100644
index 00000000..e1bca36b
--- /dev/null
+++ b/src/Upgrades/Upgrade10.php
@@ -0,0 +1,42 @@
+<?php
+namespace Szurubooru\Upgrades;
+
+class Upgrade10 implements IUpgrade
+{
+	public function run(\Szurubooru\DatabaseConnection $databaseConnection)
+	{
+		$pdo = $databaseConnection->getPDO();
+
+		$pdo->exec('ALTER TABLE posts ADD COLUMN favCount INTEGER NOT NULL DEFAULT 0');
+
+		$pdo->exec('CREATE TABLE favorites
+			(
+				id INTEGER PRIMARY KEY NOT NULL,
+				userId INTEGER NOT NULL,
+				postId INTEGER NOT NULL,
+				UNIQUE (userId, postId)
+			)');
+
+		$pdo->exec('
+			CREATE TRIGGER favoritesDelete BEFORE DELETE ON favorites
+			FOR EACH ROW
+			BEGIN
+				UPDATE posts SET favCount = favCount - 1 WHERE posts.id = OLD.postId;
+			END');
+
+		$pdo->exec('
+			CREATE TRIGGER favoritesInsert AFTER INSERT ON favorites
+			FOR EACH ROW
+			BEGIN
+				UPDATE posts SET favCount = favCount + 1 WHERE posts.id = NEW.postId;
+			END');
+
+		$pdo->exec('
+			CREATE TRIGGER favoritesUpdate AFTER UPDATE ON favorites
+			FOR EACH ROW
+			BEGIN
+				UPDATE posts SET favCount = favCount + 1 WHERE posts.id = NEW.postId;
+				UPDATE posts SET favCount = favCount - 1 WHERE posts.id = NEW.postId;
+			END');
+	}
+}
diff --git a/src/di.php b/src/di.php
index f3695c17..ed3357a7 100644
--- a/src/di.php
+++ b/src/di.php
@@ -25,6 +25,7 @@ return [
 			$container->get(\Szurubooru\Upgrades\Upgrade07::class),
 			$container->get(\Szurubooru\Upgrades\Upgrade08::class),
 			$container->get(\Szurubooru\Upgrades\Upgrade09::class),
+			$container->get(\Szurubooru\Upgrades\Upgrade10::class),
 		];
 	}),
 
@@ -37,6 +38,7 @@ return [
 			$container->get(\Szurubooru\Controllers\PostContentController::class),
 			$container->get(\Szurubooru\Controllers\GlobalParamController::class),
 			$container->get(\Szurubooru\Controllers\HistoryController::class),
+			$container->get(\Szurubooru\Controllers\FavoritesController::class),
 		];
 	}),
 ];
diff --git a/tests/AbstractDatabaseTestCase.php b/tests/AbstractDatabaseTestCase.php
index 42fa02f2..18d55c83 100644
--- a/tests/AbstractDatabaseTestCase.php
+++ b/tests/AbstractDatabaseTestCase.php
@@ -25,30 +25,4 @@ abstract class AbstractDatabaseTestCase extends \Szurubooru\Tests\AbstractTestCa
 		if ($this->databaseConnection)
 			$this->databaseConnection->close();
 	}
-
-	protected function assertEntitiesEqual($expected, $actual)
-	{
-		if (!is_array($expected))
-		{
-			$expected = [$expected];
-			$actual = [$actual];
-		}
-		$this->assertEquals(count($expected), count($actual), 'Unmatching array sizes');
-		$this->assertEquals(array_keys($expected), array_keys($actual), 'Unmatching array keys');
-		foreach (array_keys($expected) as $key)
-		{
-			if ($expected[$key] === null)
-			{
-				$this->assertNull($actual[$key]);
-			}
-			else
-			{
-				$expected[$key]->resetLazyLoaders();
-				$expected[$key]->resetMeta();
-				$actual[$key]->resetLazyLoaders();
-				$actual[$key]->resetMeta();
-				$this->assertEquals($expected[$key], $actual[$key]);
-			}
-		}
-	}
 }
diff --git a/tests/AbstractTestCase.php b/tests/AbstractTestCase.php
index e78f38d4..4df4d8ab 100644
--- a/tests/AbstractTestCase.php
+++ b/tests/AbstractTestCase.php
@@ -3,39 +3,6 @@ namespace Szurubooru\Tests;
 
 abstract class AbstractTestCase extends \PHPUnit_Framework_TestCase
 {
-	public function mock($className)
-	{
-		return $this->getMockBuilder($className)->disableOriginalConstructor()->getMock();
-	}
-
-	public function mockConfig($dataPath = null, $publicDataPath = null)
-	{
-		return new ConfigMock($dataPath, $publicDataPath);
-	}
-
-	public function mockTransactionManager()
-	{
-		return new TransactionManagerMock($this->mock(\Szurubooru\DatabaseConnection::class));
-	}
-
-	public function createTestDirectory()
-	{
-		$path = $this->getTestDirectoryPath();
-		if (!file_exists($path))
-			mkdir($path, 0777, true);
-		return $path;
-	}
-
-	public function getTestFile($fileName)
-	{
-		return file_get_contents($this->getTestFilePath($fileName));
-	}
-
-	public function getTestFilePath($fileName)
-	{
-		return __DIR__ . DIRECTORY_SEPARATOR . 'test_files' . DIRECTORY_SEPARATOR . $fileName;
-	}
-
 	protected function setUp()
 	{
 		\Szurubooru\Injector::init();
@@ -46,6 +13,66 @@ abstract class AbstractTestCase extends \PHPUnit_Framework_TestCase
 		$this->cleanTestDirectory();
 	}
 
+	protected function mock($className)
+	{
+		return $this->getMockBuilder($className)->disableOriginalConstructor()->getMock();
+	}
+
+	protected function mockConfig($dataPath = null, $publicDataPath = null)
+	{
+		return new ConfigMock($dataPath, $publicDataPath);
+	}
+
+	protected function mockTransactionManager()
+	{
+		return new TransactionManagerMock($this->mock(\Szurubooru\DatabaseConnection::class));
+	}
+
+	protected function createTestDirectory()
+	{
+		$path = $this->getTestDirectoryPath();
+		if (!file_exists($path))
+			mkdir($path, 0777, true);
+		return $path;
+	}
+
+	protected function getTestFile($fileName)
+	{
+		return file_get_contents($this->getTestFilePath($fileName));
+	}
+
+	protected function getTestFilePath($fileName)
+	{
+		return __DIR__ . DIRECTORY_SEPARATOR . 'test_files' . DIRECTORY_SEPARATOR . $fileName;
+	}
+
+	protected function assertEntitiesEqual($expected, $actual)
+	{
+		if (!is_array($expected))
+		{
+			$expected = [$expected];
+			$actual = [$actual];
+		}
+		$this->assertEquals(count($expected), count($actual), 'Unmatching array sizes');
+		$this->assertEquals(array_keys($expected), array_keys($actual), 'Unmatching array keys');
+		foreach (array_keys($expected) as $key)
+		{
+			if ($expected[$key] === null)
+			{
+				$this->assertNull($actual[$key]);
+			}
+			else
+			{
+				$this->assertNotNull($actual[$key]);
+				$expected[$key]->resetLazyLoaders();
+				$expected[$key]->resetMeta();
+				$actual[$key]->resetLazyLoaders();
+				$actual[$key]->resetMeta();
+				$this->assertEquals($expected[$key], $actual[$key]);
+			}
+		}
+	}
+
 	private function getTestDirectoryPath()
 	{
 		return __DIR__ . DIRECTORY_SEPARATOR . 'files';
diff --git a/tests/Dao/FavoritesDaoTest.php b/tests/Dao/FavoritesDaoTest.php
new file mode 100644
index 00000000..1f8229c7
--- /dev/null
+++ b/tests/Dao/FavoritesDaoTest.php
@@ -0,0 +1,82 @@
+<?php
+namespace Szurubooru\Tests\Dao;
+
+class FavoritesDaoTest extends \Szurubooru\Tests\AbstractDatabaseTestCase
+{
+	private $userDaoMock;
+	private $postDaoMock;
+
+	public function setUp()
+	{
+		parent::setUp();
+		$this->userDaoMock = $this->mock(\Szurubooru\Dao\UserDao::class);
+		$this->postDaoMock = $this->mock(\Szurubooru\Dao\PostDao::class);
+	}
+
+	public function testSaving()
+	{
+		$user = new \Szurubooru\Entities\User(1);
+		$user->setName('olivia');
+
+		$post = new \Szurubooru\Entities\Post(2);
+		$post->setName('sword');
+
+		$favorite = new \Szurubooru\Entities\Favorite();
+		$favorite->setUser($user);
+		$favorite->setPost($post);
+		$favoritesDao = $this->getFavoritesDao();
+		$favoritesDao->save($favorite);
+
+		$this->userDaoMock->expects($this->once())->method('findById')->with(1)->willReturn($user);
+		$this->postDaoMock->expects($this->once())->method('findById')->with(2)->willReturn($post);
+
+		$savedFavorite = $favoritesDao->findById($favorite->getId());
+		$this->assertEquals(1, $savedFavorite->getUserId());
+		$this->assertEquals(2, $savedFavorite->getPostId());
+		$this->assertEntitiesEqual($user, $savedFavorite->getUser());
+		$this->assertEntitiesEqual($post, $savedFavorite->getPost());
+	}
+
+	public function testFindingByUserAndPost()
+	{
+		$post1 = new \Szurubooru\Entities\Post(1);
+		$post2 = new \Szurubooru\Entities\Post(2);
+		$user1 = new \Szurubooru\Entities\User(3);
+		$user2 = new \Szurubooru\Entities\User(4);
+
+		$fav1 = new \Szurubooru\Entities\Favorite();
+		$fav1->setUser($user1);
+		$fav1->setPost($post1);
+
+		$fav2 = new \Szurubooru\Entities\Favorite();
+		$fav2->setUser($user2);
+		$fav2->setPost($post2);
+
+		$fav3 = new \Szurubooru\Entities\Favorite();
+		$fav3->setUser($user1);
+		$fav3->setPost($post2);
+
+		$favoritesDao = $this->getFavoritesDao();
+		$favoritesDao->save($fav1);
+		$favoritesDao->save($fav2);
+		$favoritesDao->save($fav3);
+
+		$this->assertEntitiesEqual($fav1, $favoritesDao->findByUserAndPost($user1, $post1));
+		$this->assertEntitiesEqual($fav2, $favoritesDao->findByUserAndPost($user2, $post2));
+		$this->assertEntitiesEqual($fav3, $favoritesDao->findByUserAndPost($user1, $post2));
+		$this->assertNull($favoritesDao->findByUserAndPost($user2, $post1));
+	}
+
+	public function findByPost(\Szurubooru\Entities\Post $post)
+	{
+		return $this->findOneBy('postId', $post->getId());
+	}
+
+	private function getFavoritesDao()
+	{
+		return new \Szurubooru\Dao\FavoritesDao(
+			$this->databaseConnection,
+			$this->userDaoMock,
+			$this->postDaoMock);
+	}
+}
diff --git a/tests/Services/FavoritesServiceTest.php b/tests/Services/FavoritesServiceTest.php
new file mode 100644
index 00000000..96ba936b
--- /dev/null
+++ b/tests/Services/FavoritesServiceTest.php
@@ -0,0 +1,83 @@
+<?php
+namespace Szurubooru\Tests\Services;
+
+final class FavoritesServiceTest extends \Szurubooru\Tests\AbstractTestCase
+{
+	private $favoritesDaoMock;
+	private $userDaoMock;
+	private $transactionManagerMock;
+
+	public function setUp()
+	{
+		parent::setUp();
+		$this->favoritesDaoMock = $this->mock(\Szurubooru\Dao\FavoritesDao::class);
+		$this->userDaoMock = $this->mock(\Szurubooru\Dao\UserDao::class);
+		$this->transactionManagerMock = $this->mockTransactionManager();
+	}
+
+	public function testAddingExisting()
+	{
+		$user = new \Szurubooru\Entities\User();
+		$post = new \Szurubooru\Entities\Post();
+		$fav = new \Szurubooru\Entities\Favorite(3);
+		$this->favoritesDaoMock->expects($this->once())->method('findByUserAndPost')->with($user, $post)->willReturn($fav);
+		$this->favoritesDaoMock->expects($this->never())->method('save');
+
+		$favoritesService = $this->getFavoritesService();
+		$favoritesService->addFavorite($user, $post);
+	}
+
+	public function testAdding()
+	{
+		$user = new \Szurubooru\Entities\User(1);
+		$post = new \Szurubooru\Entities\Post(2);
+		$fav = new \Szurubooru\Entities\Favorite();
+		$fav->setUserId($user->getId());
+		$fav->setPostId($post->getId());
+		$this->favoritesDaoMock->expects($this->once())->method('findByUserAndPost')->with($user, $post)->willReturn(null);
+		$this->favoritesDaoMock->expects($this->once())->method('save')->with($this->callback(
+			function($subject) use ($fav)
+			{
+				$this->assertEntitiesEqual($fav, $subject);
+				return true;
+			}));
+
+		$favoritesService = $this->getFavoritesService();
+		$favoritesService->addFavorite($user, $post);
+	}
+
+	public function testDeleting()
+	{
+		$user = new \Szurubooru\Entities\User();
+		$post = new \Szurubooru\Entities\Post();
+		$fav = new \Szurubooru\Entities\Favorite(3);
+		$this->favoritesDaoMock->expects($this->once())->method('findByUserAndPost')->with($user, $post)->willReturn($fav);
+		$this->favoritesDaoMock->expects($this->once())->method('deleteById')->with($fav->getId());
+
+		$favoritesService = $this->getFavoritesService();
+		$favoritesService->deleteFavorite($user, $post);
+	}
+
+	public function testGettingByPost()
+	{
+		$post = new \Szurubooru\Entities\Post();
+		$fav1 = new \Szurubooru\Entities\Favorite();
+		$fav2 = new \Szurubooru\Entities\Favorite();
+		$fav1->setUser(new \Szurubooru\Entities\User(1));
+		$fav2->setUser(new \Szurubooru\Entities\User(2));
+
+		$this->favoritesDaoMock->expects($this->once())->method('findByPost')->with($post)->willReturn([$fav1, $fav2]);
+		$this->userDaoMock->expects($this->once())->method('findByIds')->with([1, 2]);
+
+		$favoritesService = $this->getFavoritesService();
+		$favoritesService->getFavoriteUsers($post);
+	}
+
+	private function getFavoritesService()
+	{
+		return new \Szurubooru\Services\FavoritesService(
+			$this->favoritesDaoMock,
+			$this->userDaoMock,
+			$this->transactionManagerMock);
+	}
+}