diff --git a/readme.md b/readme.md
index fbdb4ee..2dbd1fa 100644
--- a/readme.md
+++ b/readme.md
@@ -12,18 +12,18 @@ A Groove Music like music player.
 
 ## Changes since lastest release
 - add resource collection
+- add tag caching
 - fix library hovering
-- improve song transition
+- improve start time
 - improve load time
 - improve cache performance
+- improve song transition
 
 ## Things to do
 
 ### Internal
 - move library into music library
 - use a member query
-- split utils but keep header
-- cache all audio information
 - use QFileSystemWatcher
 
 ### Cosmetic
diff --git a/src/core/audio.cpp b/src/core/audio.cpp
index 1e29feb..519a353 100644
--- a/src/core/audio.cpp
+++ b/src/core/audio.cpp
@@ -26,6 +26,34 @@ Audio::Audio(const QString &path) :
         m_title = FileUtil::fileName(m_path);
 }
 
+/*
+ * Constructor. Used to read audios from the sql database.
+ *
+ * :param path: path
+ * :param title: title
+ * :param artist: artist
+ * :param album: album
+ * :param genre: genre
+ * :param year: year
+ * :param length: length
+ * :param coverId: cover id
+ */
+Audio::Audio(const QString &path, const QString &title, const QString &artist, const QString &album,
+             const QString &genre, int year, int track, int length, int coverId) :
+    m_valid(true),
+    m_path(path),
+    m_title(title),
+    m_artist(artist),
+    m_album(album),
+    m_genre(genre),
+    m_year(year),
+    m_track(track),
+    m_length(length),
+    m_coverId(coverId)
+{
+
+}
+
 /*
  * Destructor.
  */
diff --git a/src/core/audio.hpp b/src/core/audio.hpp
index 7a3c536..1427cf2 100644
--- a/src/core/audio.hpp
+++ b/src/core/audio.hpp
@@ -22,6 +22,8 @@ class Audio
 {
 public:
     Audio(const QString &path);
+    Audio(const QString &path, const QString &title, const QString &artist, const QString &album,
+          const QString &genre, int year, int track, int length, int coverId);
     ~Audio();
 
     bool isValid() const;
diff --git a/src/core/cache.cpp b/src/core/cache.cpp
index 39e7255..55aa017 100644
--- a/src/core/cache.cpp
+++ b/src/core/cache.cpp
@@ -6,13 +6,13 @@
  */
 Cache::Cache()
 {    
-    if (QSqlDatabase::contains(dbName()))
-        return;
-
-    QSqlDatabase::addDatabase("QSQLITE", dbName());
+    if (!QSqlDatabase::contains(dbName()))
+    {
+        QSqlDatabase::addDatabase("QSQLITE", dbName());
 
-    createCovers();
-    createAudios();
+        createCovers();
+        createAudios();
+    }
 }
 
 /*
@@ -24,16 +24,89 @@ Cache::~Cache()
 }
 
 /*
- * Inserts audio into cache. It adds the cover into the covers table and the
- * path with a cover id into the audios table. No tags are stored inside the
- * cache because TagLib is fast enough to reload tags at every startup.
- * Also sets the cover id for later use.
+ * Loads an audio file from the cache. If it does not exist a nullptr will be
+ * returned instead.
+ *
+ * :param path: path
+ * :return: audio, nullptr at failure
+ */
+Audio * Cache::load(const QString &path)
+{
+    Audio *audio = nullptr;
+
+    QSqlQuery query(db());
+    query.prepare("SELECT * FROM audios WHERE path = :path");
+    query.bindValue(":path", path);
+
+    if (!query.exec())
+        handleError(query);
+
+    if (query.first())
+    {
+        audio = new Audio(
+            query.value(0).toString(),
+            query.value(1).toString(),
+            query.value(2).toString(),
+            query.value(3).toString(),
+            query.value(4).toString(),
+            query.value(5).toInt(),
+            query.value(6).toInt(),
+            query.value(7).toInt(),
+            query.value(8).toInt()
+        );
+    }
+    return audio;
+}
+
+/*
+ * Inserts audio tags into the cache.
+ *
+ * :param audio: audio
+ * :return: success
+ */
+bool Cache::insertAudio(Audio *audio)
+{
+    QSqlQuery query(db());
+    query.prepare(
+        "INSERT INTO audios VALUES ("
+        " :path,"
+        " :title,"
+        " :artist,"
+        " :album,"
+        " :genre,"
+        " :year,"
+        " :track,"
+        " :length,"
+        " :coverid"
+        ")"
+    );
+    query.bindValue(":path", audio->path());
+    query.bindValue(":title", audio->title());
+    query.bindValue(":artist", audio->artist());
+    query.bindValue(":album", audio->album());
+    query.bindValue(":genre", audio->genre());
+    query.bindValue(":year", audio->year());
+    query.bindValue(":track", audio->track());
+    query.bindValue(":length", audio->length(false));
+    query.bindValue(":coverid", audio->coverId());
+
+    if (!query.exec())
+    {
+        handleError(query);
+        return false;
+    }
+    return true;
+}
+
+/*
+ * Inserts an audio cover into the cache. This assumes that the audio already
+ * has an entry in the audio table.
  *
  * :param audio: audio
  * :param size: cover size, default 200
  * :return: success
  */
-bool Cache::insert(Audio *audio, int size)
+bool Cache::insertCover(Audio *audio, int size)
 {
     int id = getOrInsertCover(audio->cover(size));
     if (id == -1)
@@ -42,7 +115,11 @@ bool Cache::insert(Audio *audio, int size)
     audio->setCoverId(id);
 
     QSqlQuery query(db());
-    query.prepare("INSERT INTO audios VALUES (:path, :coverid)");
+    query.prepare(
+        "UPDATE audios "
+        "SET coverid = :coverid "
+        "WHERE path = :path"
+    );
     query.bindValue(":path", audio->path());
     query.bindValue(":coverid", id);
 
@@ -55,7 +132,9 @@ bool Cache::insert(Audio *audio, int size)
 }
 
 /*
- * Checks if database contains audio. Also sets the cover id for later use.
+ * Checks if database contains audio. Also sets the cover id for later use. If
+ * an audio object has a valid cover id it definitely exists already because it
+ * only gets set inside the cache.
  *
  * :param audio: audio
  * :return: contains
@@ -78,7 +157,11 @@ bool Cache::contains(Audio *audio)
     if (!query.first())
         return false;
 
-    audio->setCoverId(query.value(0).toInt());
+    int id = query.value(0).toInt();
+    if (id == -1)
+        return false;
+
+    audio->setCoverId(id);
 
     return true;
 }
@@ -182,8 +265,14 @@ void Cache::createAudios()
     QString createAudios =
         "CREATE TABLE IF NOT EXISTS audios("
         " path TEXT PRIMARY KEY,"
-        " coverid INTEGER,"
-        " FOREIGN KEY (coverid) REFERENCES covers(id)"
+        " title TEXT,"
+        " artist TEXT,"
+        " album TEXT,"
+        " genre TEXT,"
+        " year INTEGER,"
+        " track INTEGER,"
+        " length INTEGER,"
+        " coverid INTEGER"
         ")";
 
     QSqlQuery query(db());
diff --git a/src/core/cache.hpp b/src/core/cache.hpp
index 18c5fa7..eb65a80 100644
--- a/src/core/cache.hpp
+++ b/src/core/cache.hpp
@@ -19,7 +19,11 @@ class Cache
     Cache();
     ~Cache();
 
-    bool insert(Audio *audio, int size = 200);
+    Audio * load(const QString &path);
+
+    bool insertAudio(Audio *audio);
+    bool insertCover(Audio *audio, int size = 200);
+
     bool contains(Audio *audio);
     QPixmap cover(Audio *audio, int size = 200);
 
diff --git a/src/core/library.cpp b/src/core/library.cpp
index 3e5d4f3..44ea98e 100644
--- a/src/core/library.cpp
+++ b/src/core/library.cpp
@@ -8,11 +8,12 @@
 Library::Library(QObject *parent) :
     QObject(parent),
     m_sorted(false),
-    pm_audioPool(new ThreadPool(this)),
-    pm_cachePool(new ThreadPool(this))
+    pm_audioLoader(new AudioLoader(this)),
+    pm_cacheBuilder(new CacheBuilder(this))
 {
-    connect(pm_audioPool, SIGNAL(finished()), this, SLOT(onAudioPoolFinished()));
-    connect(pm_audioPool, SIGNAL(finished()), this, SIGNAL(loaded()));
+    connect(pm_audioLoader, SIGNAL(loaded(Audio *)), this, SLOT(insert(Audio *)));
+    connect(pm_audioLoader, SIGNAL(finished()), this, SLOT(onAudioLoaderFinished()));
+    connect(pm_audioLoader, SIGNAL(finished()), this, SIGNAL(loaded()));
 }
 
 /*
@@ -89,14 +90,8 @@ Audios Library::audios() const
  */
 void Library::load(const StringList &paths)
 {
-    QVector<StringList> chunks = Util::chunk(uniqueFiles(paths), pm_audioPool->advised());
-    for (const StringList &chunk : chunks)
-    {
-        AudioLoader *loader = new AudioLoader(chunk);
-        connect(loader, SIGNAL(loaded(Audio *)), this, SLOT(insert(Audio *)));
-        pm_audioPool->add(loader);
-    }
-    pm_audioPool->start();
+    pm_audioLoader->setFiles(uniqueFiles(paths));
+    pm_audioLoader->start();
 }
 
 /*
@@ -107,21 +102,19 @@ void Library::load(const StringList &paths)
  */
 void Library::insert(Audio *audio)
 {
-    m_mutex.lock();
     if (m_sorted)
         insertBinary(audio);
     else
         append(audio);
-    m_mutex.unlock();
 }
 
 /*
  * Gets called when the library is loaded and creates the cache builder.
  */
-void Library::onAudioPoolFinished()
+void Library::onAudioLoaderFinished()
 {
-    pm_cachePool->add(new CacheBuilder(m_audios));
-    pm_cachePool->start();
+    pm_cacheBuilder->setAudios(m_audios);
+    pm_cacheBuilder->start();
 }
 
 /*
diff --git a/src/core/library.hpp b/src/core/library.hpp
index 115fd0d..7859f91 100644
--- a/src/core/library.hpp
+++ b/src/core/library.hpp
@@ -39,7 +39,7 @@ public slots:
     void inserted(Audio *, int);
 
 private slots:
-    void onAudioPoolFinished();
+    void onAudioLoaderFinished();
 
 private:
     int lowerBound(Audio *audio);
@@ -50,8 +50,8 @@ private slots:
 
     bool m_sorted;
     Audios m_audios;
-    ThreadPool *pm_audioPool;
-    ThreadPool *pm_cachePool;
+    AudioLoader *pm_audioLoader;
+    CacheBuilder *pm_cacheBuilder;
     QMutex m_mutex;
     QSet<QString> m_paths;
 
diff --git a/src/core/threading/abstractthread.cpp b/src/core/threading/abstractthread.cpp
index 6d1b523..9d5ecd6 100644
--- a/src/core/threading/abstractthread.cpp
+++ b/src/core/threading/abstractthread.cpp
@@ -40,6 +40,7 @@ bool AbstractThread::isAbort() const
 void AbstractThread::abort()
 {
     m_abort = true;
-    quit();
-    wait();
+
+    if (!wait(5000))
+        Logger::log("AbstractThread: Could not abort within 5 seconds");
 }
diff --git a/src/core/threading/abstractthread.hpp b/src/core/threading/abstractthread.hpp
index 4979eb6..e716fb3 100644
--- a/src/core/threading/abstractthread.hpp
+++ b/src/core/threading/abstractthread.hpp
@@ -3,6 +3,8 @@
 
 #include <QThread>
 
+#include "logger.hpp"
+
 class AbstractThread : public QThread
 {
     Q_OBJECT
diff --git a/src/core/threading/audioloader.cpp b/src/core/threading/audioloader.cpp
index 63a838b..a72f056 100644
--- a/src/core/threading/audioloader.cpp
+++ b/src/core/threading/audioloader.cpp
@@ -47,12 +47,19 @@ void AudioLoader::setFiles(const StringList &files)
  */
 void AudioLoader::run()
 {
+    Cache cache;
     for (const QString &file : m_files)
     {
         if (isAbort())
             return;
 
-        Audio *audio = new Audio(file);
+        Audio *audio = cache.load(file);
+        if (!audio)
+        {
+            audio = new Audio(file);
+            cache.insertAudio(audio);
+        }
+
         if (audio->isValid())
             emit loaded(audio);
         else
diff --git a/src/core/threading/audioloader.hpp b/src/core/threading/audioloader.hpp
index 0e152d3..05dd3ac 100644
--- a/src/core/threading/audioloader.hpp
+++ b/src/core/threading/audioloader.hpp
@@ -3,6 +3,7 @@
 
 #include "abstractthread.hpp"
 #include "audio.hpp"
+#include "cache.hpp"
 #include "logger.hpp"
 #include "types.hpp"
 #include "utils.hpp"
diff --git a/src/core/threading/cachebuilder.cpp b/src/core/threading/cachebuilder.cpp
index 5b51d92..6df7924 100644
--- a/src/core/threading/cachebuilder.cpp
+++ b/src/core/threading/cachebuilder.cpp
@@ -45,15 +45,19 @@ void CacheBuilder::setAudios(const Audios &audios)
 /*
  * Loads audio covers.
  */
+#include <QDebug>
 void CacheBuilder::run()
 {
     Cache cache;
     for (Audio *audio : m_audios)
     {
         if (isAbort())
+        {
+            qDebug() << "aborted :|";
             return;
+        }
 
         if (!cache.contains(audio))
-            cache.insert(audio);
+            cache.insertCover(audio);
     }
 }