diff --git a/src/updatechecker.cpp b/src/updatechecker.cpp
new file mode 100644
--- /dev/null
+++ b/src/updatechecker.cpp
@@ -0,0 +1,222 @@
+/*
+  Copyright © 2017 Hasan Yavuz Özderya
+
+  This file is part of serialplot.
+
+  serialplot is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  serialplot is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with serialplot.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <QJsonDocument>
+#include <QJsonObject>
+#include <QJsonArray>
+#include <QJsonValue>
+#include <QRegularExpression>
+#include <algorithm>
+#include <functional>
+
+#include "updatechecker.h"
+
+// This link returns the list of downloads in JSON format. Note that we only use
+// the first page because results are sorted new to old.
+const char BB_DOWNLOADS_URL[] = "https://api.bitbucket.org/2.0/repositories/hyozd/serialplot/downloads?fields=values.name,values.links.self.href";
+
+UpdateChecker::UpdateChecker(QObject *parent) :
+    QObject(parent), nam(this)
+{
+    activeReply = NULL;
+
+    connect(&nam, &QNetworkAccessManager::finished,
+            this, &UpdateChecker::onReqFinished);
+}
+
+bool UpdateChecker::isChecking() const
+{
+    return activeReply != NULL && !activeReply->isFinished();
+}
+
+void UpdateChecker::checkUpdate()
+{
+    if (isChecking()) return;
+
+    auto req = QNetworkRequest(QUrl(BB_DOWNLOADS_URL));
+    activeReply = nam.get(req);
+}
+
+void UpdateChecker::cancelCheck()
+{
+    if (activeReply != NULL) activeReply->abort();
+}
+
+void UpdateChecker::onReqFinished(QNetworkReply* reply)
+{
+    if (reply->error() != QNetworkReply::NoError)
+    {
+        emit checkFailed(QString("Network error: ") + reply->errorString());
+    }
+    else
+    {
+        QJsonParseError error;
+        auto data = QJsonDocument::fromJson(reply->readAll(), &error);
+        if (error.error != QJsonParseError::NoError)
+        {
+            emit checkFailed(QString("JSon parsing error: ") + error.errorString());
+        }
+        else
+        {
+            QList<FileInfo> files;
+            if (!parseData(data, files))
+            {
+                // TODO: emit detailed data contents for logging
+                emit checkFailed("Data parsing error.");
+            }
+            else
+            {
+                FileInfo updateFile;
+                if (findUpdate(files, updateFile))
+                {
+                    emit checkFinished(
+                        true, updateFile.version.toString(), updateFile.link);
+                }
+                else
+                {
+                    emit checkFinished(false, "", "");
+                }
+            }
+        }
+    }
+    reply->deleteLater();
+    activeReply = NULL;
+}
+
+bool UpdateChecker::parseData(const QJsonDocument& data, QList<FileInfo>& files) const
+{
+    /* Data is expected to be in this form:
+
+    {
+       "values": [
+       {
+         "name": "serialplot-0.9.1-x86_64.AppImage",
+         "links": {
+           "self": {
+             "href": "https://api.bitbucket.org/2.0/repositories/hyOzd/serialplot/downloads/serialplot-0.9.1-x86_64.AppImage"
+            }
+          }
+       }, ... ]
+    }
+    */
+
+    if (!data.isObject()) return false;
+
+    auto values = data.object()["values"];
+    if (values == QJsonValue::Undefined || !values.isArray()) return false;
+
+    for (auto value : values.toArray())
+    {
+        if (!value.isObject()) return false;
+
+        auto name = value.toObject().value("name");
+        if (name.isUndefined() || !name.isString())
+             return false;
+
+        auto links = value.toObject().value("links");
+        if (links.isUndefined() || !links.isObject())
+            return false;
+
+        auto self = links.toObject().value("self");
+        if (self.isUndefined() || !self.isObject())
+            return false;
+
+        auto href = self.toObject().value("href");
+        if (href.isUndefined() || !href.isString())
+            return false;
+
+        FileInfo finfo;
+        finfo.name = name.toString();
+        finfo.link = href.toString();
+        finfo.hasVersion = VersionNumber::extract(name.toString(), finfo.version);
+
+        if (finfo.name.contains("amd64") ||
+            finfo.name.contains("x86_64") ||
+            finfo.name.contains("win64"))
+        {
+            finfo.arch = FileArch::amd64;
+        }
+        else if (finfo.name.contains("win32") ||
+                 finfo.name.contains("i386"))
+        {
+            finfo.arch = FileArch::i386;
+        }
+        else
+        {
+            finfo.arch = FileArch::unknown;
+        }
+
+        files += finfo;
+    }
+
+    return true;
+}
+
+bool UpdateChecker::findUpdate(const QList<FileInfo>& files, FileInfo& foundFile) const
+{
+    QList<FileInfo> fflist;
+
+    // filter the file list according to extension and version number
+    for (int i = 0; i < files.length(); i++)
+    {
+        // file type to look
+#if defined(Q_OS_WIN)
+        const char ext[] = ".exe";
+#else  // of course linux
+        const char ext[] = ".appimage";
+#endif
+
+        // file architecture to look
+#if defined(Q_PROCESSOR_X86_64)
+        const FileArch arch = FileArch::amd64;
+#elif defined(Q_PROCESSOR_X86_32)
+        const FileArch arch = FileArch::i386;
+#elif defined(Q_PROCESSOR_ARM)
+        const FileArch arch = FileArch::arm;
+#else
+        #error Unknown architecture for update file detection.
+#endif
+
+        // filter the file list
+        auto file = files[i];
+        if (file.name.contains(ext, Qt::CaseInsensitive) &&
+            file.arch == arch &&
+            file.hasVersion && file.version > CurrentVersion)
+        {
+            fflist += file;
+        }
+    }
+
+    // sort and find most up to date file
+    if (!fflist.empty())
+    {
+        std::sort(fflist.begin(), fflist.end(),
+                  [](const FileInfo& a, const FileInfo& b)
+                  {
+                      return a.version > b.version;
+                  });
+
+        foundFile = fflist[0];
+        return true;
+    }
+    else
+    {
+        return false;
+    }
+}