diff --git a/distribution/changelog.txt b/distribution/changelog.txt
index f0c2a3da24..eda7cd7591 100644
--- a/distribution/changelog.txt
+++ b/distribution/changelog.txt
@@ -20,6 +20,7 @@
 - Fix: [#14587] Confusing message when joining server with mismatched network version.
 - Fix: [#14604] American-style Steam Trains are not imported correctly from RCT1 saves.
 - Fix: [#14638] The “About OpenRCT2” window cannot be themed.
+- Improved: [#14712]: Improve startup times.
 
 0.3.3 (2021-03-13)
 ------------------------------------------------------------------------
diff --git a/src/openrct2/core/File.cpp b/src/openrct2/core/File.cpp
index df722e1196..4e7eba3fea 100644
--- a/src/openrct2/core/File.cpp
+++ b/src/openrct2/core/File.cpp
@@ -1,5 +1,5 @@
 /*****************************************************************************
- * Copyright (c) 2014-2020 OpenRCT2 developers
+ * Copyright (c) 2014-2021 OpenRCT2 developers
  *
  * For a complete list of all authors, please refer to contributors.md
  * Interested in contributing? Visit https://github.com/OpenRCT2/OpenRCT2
@@ -57,8 +57,7 @@ namespace File
         }
 
         std::vector<uint8_t> result;
-        fs.seekg(0, std::ios::end);
-        auto fsize = static_cast<size_t>(fs.tellg());
+        auto fsize = Platform::GetFileSize(path);
         if (fsize > SIZE_MAX)
         {
             std::string message = String::StdFormat(
@@ -68,7 +67,6 @@ namespace File
         else
         {
             result.resize(fsize);
-            fs.seekg(0);
             fs.read(reinterpret_cast<char*>(result.data()), result.size());
             fs.exceptions(fs.failbit);
         }
@@ -123,6 +121,11 @@ namespace File
     {
         return Platform::GetLastModified(path);
     }
+
+    uint64_t GetSize(std::string_view path)
+    {
+        return Platform::GetFileSize(path);
+    }
 } // namespace File
 
 bool writeentirefile(const utf8* path, const void* buffer, size_t length)
diff --git a/src/openrct2/core/File.h b/src/openrct2/core/File.h
index 9dc216042e..cdd6179fa7 100644
--- a/src/openrct2/core/File.h
+++ b/src/openrct2/core/File.h
@@ -1,5 +1,5 @@
 /*****************************************************************************
- * Copyright (c) 2014-2020 OpenRCT2 developers
+ * Copyright (c) 2014-2021 OpenRCT2 developers
  *
  * For a complete list of all authors, please refer to contributors.md
  * Interested in contributing? Visit https://github.com/OpenRCT2/OpenRCT2
@@ -26,4 +26,5 @@ namespace File
     std::vector<std::string> ReadAllLines(std::string_view path);
     void WriteAllBytes(const std::string& path, const void* buffer, size_t length);
     uint64_t GetLastModified(const std::string& path);
+    uint64_t GetSize(std::string_view path);
 } // namespace File
diff --git a/src/openrct2/core/FileStream.cpp b/src/openrct2/core/FileStream.cpp
index 3a1ff1654b..68c0b52692 100644
--- a/src/openrct2/core/FileStream.cpp
+++ b/src/openrct2/core/FileStream.cpp
@@ -1,5 +1,5 @@
 /*****************************************************************************
- * Copyright (c) 2014-2020 OpenRCT2 developers
+ * Copyright (c) 2014-2021 OpenRCT2 developers
  *
  * For a complete list of all authors, please refer to contributors.md
  * Interested in contributing? Visit https://github.com/OpenRCT2/OpenRCT2
@@ -16,6 +16,8 @@
 
 #ifndef _WIN32
 #    include <sys/stat.h>
+#else
+#    include <io.h>
 #endif
 
 #if defined(__linux__) && !defined(__ANDROID__)
@@ -98,9 +100,12 @@ namespace OpenRCT2
             throw IOException(String::StdFormat("Unable to open '%s'", path));
         }
 
-        Seek(0, STREAM_SEEK_END);
-        _fileSize = GetPosition();
-        Seek(0, STREAM_SEEK_BEGIN);
+#ifdef _WIN32
+        _fileSize = _filelengthi64(_fileno(_file));
+#else
+        std::error_code ec;
+        _fileSize = fs::file_size(fs::u8path(path), ec);
+#endif
 
         _ownsFilePtr = true;
     }
@@ -160,13 +165,9 @@ namespace OpenRCT2
 
     void FileStream::Read(void* buffer, uint64_t length)
     {
-        uint64_t remainingBytes = GetLength() - GetPosition();
-        if (length <= remainingBytes)
+        if (fread(buffer, 1, static_cast<size_t>(length), _file) == length)
         {
-            if (fread(buffer, static_cast<size_t>(length), 1, _file) == 1)
-            {
-                return;
-            }
+            return;
         }
         throw IOException("Attempted to read past end of file.");
     }
diff --git a/src/openrct2/object/Object.cpp b/src/openrct2/object/Object.cpp
index 0d221293e5..6de569acdf 100644
--- a/src/openrct2/object/Object.cpp
+++ b/src/openrct2/object/Object.cpp
@@ -1,5 +1,5 @@
 /*****************************************************************************
- * Copyright (c) 2014-2020 OpenRCT2 developers
+ * Copyright (c) 2014-2021 OpenRCT2 developers
  *
  * For a complete list of all authors, please refer to contributors.md
  * Interested in contributing? Visit https://github.com/OpenRCT2/OpenRCT2
@@ -252,18 +252,11 @@ bool ObjectAsset::IsAvailable() const
     }
 }
 
-size_t ObjectAsset::GetSize() const
+uint64_t ObjectAsset::GetSize() const
 {
     if (_zipPath.empty())
     {
-        try
-        {
-            return File::ReadAllBytes(_path).size();
-        }
-        catch (...)
-        {
-            return 0;
-        }
+        return File::GetSize(_path);
     }
     else
     {
diff --git a/src/openrct2/object/Object.h b/src/openrct2/object/Object.h
index 47e9ee87d5..7e3a496e86 100644
--- a/src/openrct2/object/Object.h
+++ b/src/openrct2/object/Object.h
@@ -1,5 +1,5 @@
 /*****************************************************************************
- * Copyright (c) 2014-2020 OpenRCT2 developers
+ * Copyright (c) 2014-2021 OpenRCT2 developers
  *
  * For a complete list of all authors, please refer to contributors.md
  * Interested in contributing? Visit https://github.com/OpenRCT2/OpenRCT2
@@ -223,7 +223,7 @@ public:
     }
 
     bool IsAvailable() const;
-    size_t GetSize() const;
+    uint64_t GetSize() const;
     std::unique_ptr<OpenRCT2::IStream> GetStream() const;
 };
 
diff --git a/src/openrct2/platform/Platform.Posix.cpp b/src/openrct2/platform/Platform.Posix.cpp
index 8889749720..dc1184564d 100644
--- a/src/openrct2/platform/Platform.Posix.cpp
+++ b/src/openrct2/platform/Platform.Posix.cpp
@@ -1,5 +1,5 @@
 /*****************************************************************************
- * Copyright (c) 2014-2020 OpenRCT2 developers
+ * Copyright (c) 2014-2021 OpenRCT2 developers
  *
  * For a complete list of all authors, please refer to contributors.md
  * Interested in contributing? Visit https://github.com/OpenRCT2/OpenRCT2
@@ -177,6 +177,19 @@ namespace Platform
         return lastModified;
     }
 
+    uint64_t GetFileSize(std::string_view path)
+    {
+        uint64_t size = 0;
+        struct stat statInfo
+        {
+        };
+        if (stat(std::string(path).c_str(), &statInfo) == 0)
+        {
+            size = statInfo.st_size;
+        }
+        return size;
+    }
+
     bool ShouldIgnoreCase()
     {
         return false;
diff --git a/src/openrct2/platform/Platform.Win32.cpp b/src/openrct2/platform/Platform.Win32.cpp
index d7d22fbbea..4a7f203e96 100644
--- a/src/openrct2/platform/Platform.Win32.cpp
+++ b/src/openrct2/platform/Platform.Win32.cpp
@@ -1,5 +1,5 @@
 /*****************************************************************************
- * Copyright (c) 2014-2020 OpenRCT2 developers
+ * Copyright (c) 2014-2021 OpenRCT2 developers
  *
  * For a complete list of all authors, please refer to contributors.md
  * Interested in contributing? Visit https://github.com/OpenRCT2/OpenRCT2
@@ -554,6 +554,21 @@ namespace Platform
         return lastModified;
     }
 
+    uint64_t GetFileSize(std::string_view path)
+    {
+        uint64_t size = 0;
+        auto pathW = String::ToWideChar(path);
+        WIN32_FILE_ATTRIBUTE_DATA attributes;
+        if (GetFileAttributesExW(pathW.c_str(), GetFileExInfoStandard, &attributes) != FALSE)
+        {
+            ULARGE_INTEGER fileSize;
+            fileSize.LowPart = attributes.nFileSizeLow;
+            fileSize.HighPart = attributes.nFileSizeHigh;
+            size = fileSize.QuadPart;
+        }
+        return size;
+    }
+
     bool ShouldIgnoreCase()
     {
         return true;
diff --git a/src/openrct2/platform/Platform2.h b/src/openrct2/platform/Platform2.h
index 6189f21b96..98d886d282 100644
--- a/src/openrct2/platform/Platform2.h
+++ b/src/openrct2/platform/Platform2.h
@@ -1,5 +1,5 @@
 /*****************************************************************************
- * Copyright (c) 2014-2020 OpenRCT2 developers
+ * Copyright (c) 2014-2021 OpenRCT2 developers
  *
  * For a complete list of all authors, please refer to contributors.md
  * Interested in contributing? Visit https://github.com/OpenRCT2/OpenRCT2
@@ -39,6 +39,7 @@ namespace Platform
     bool IsPathSeparator(char c);
     utf8* GetAbsolutePath(utf8* buffer, size_t bufferSize, const utf8* relativePath);
     uint64_t GetLastModified(const std::string& path);
+    uint64_t GetFileSize(std::string_view path);
     std::string ResolveCasing(const std::string& path, bool fileExists);
     rct2_time GetTimeLocal();
     rct2_date GetDateLocal();