LG Flash Tool – Free Download
KDZ & TOT Firmware Flasher for Windows

LG Flash Tool is a free Windows application designed to flash official KDZ and TOT firmware files onto LG Android smartphones, tablets, and feature phones. It is the primary tool for restoring the original factory software on any LG device — whether you need to fix a bootloop, recover from a bad update, repair error messages, or simply return the phone to its out-of-box state.

Unlike general-purpose Android tools, LG Flash Tool works at a low level — it communicates with the device in Download Mode, bypassing the operating system entirely. This means it can recover phones that are stuck on a logo, completely unresponsive, or showing no signs of life. It uses the UptestEX 1.2.3.1 engine internally, giving it wide compatibility across old and new LG hardware — from budget feature phones to high-end LG flagship smartphones.

The tool works without any PC suite or third-party LG support software installed. You do not need an active internet connection during the flash process. Just download the correct KDZ firmware for your LG model, install the LG USB driver, and LG Flash Tool handles the rest.

For newer LG devices running Android 6.0 Marshmallow or higher, LGUP (LG Update) is the recommended alternative that also supports KDZ files. Both tools are available on this page.

Full credit for LG Flash Tool goes to the LG Vietnam Community for developing and sharing this utility for free.

Before You Start – Requirements

You need three things before flashing: (1) the correct KDZ or TOT firmware file for your specific LG device model, (2) the LG USB driver installed on your Windows PC, and (3) LG Flash Tool extracted and ready to run. Some versions also require the MegaLock.dll file placed in the same folder as the tool.

Step-by-Step: Flash KDZ Firmware with LG Flash Tool

1. Install the LG USB driver — Download and install the LG USB driver on your Windows PC before connecting the device.
2. Download and extract LG Flash Tool — Extract the ZIP to a folder on your desktop. No installation is required — it runs as a portable app.
3. Place MegaLock.dll (if needed) — If the tool does not open, copy the MegaLock.dll file into the same folder as the LGFlashTool executable before launching again.
4. Open LGFlashTool.exe — Double-click the executable to launch LG Flash Tool.
5. Select firmware type — Under the Select Type dropdown, choose the chipset type that matches your LG device (for most modern devices, choose CDMA or the appropriate option).
6. Load the KDZ or TOT file — Click the Select File button and browse to your downloaded KDZ or TOT firmware file.
7. Boot the device into Download Mode — Power off your LG phone completely. Hold the Volume Up button, then connect the USB cable while keeping the button held. The device enters Download Mode automatically.
8. Click Normal Flash — Press the Normal Flash button to begin. A dialog box appears — click Start and choose your language if prompted.
9. Wait for completion — The flash process takes 5 to 15 minutes depending on firmware size. Do not disconnect the cable. The device reboots automatically when finished.

Using LGUP for Android 6.0+ LG Devices

LGUP is a newer LG flashing utility designed for LG phones running Android Marshmallow (6.0) and above. The flashing steps are nearly identical to LG Flash Tool — install the LG USB driver, extract LGUP, load your KDZ file, enter Download Mode, and click Start. LGUP is the recommended choice when LG Flash Tool does not recognize your newer LG model.

What is the difference between KDZ and TOT firmware?
KDZ is the standard LG firmware format used across most LG smartphones and tablets. TOT is a newer format that bundles multiple partitions into a single file, used on more recent LG device models. LG Flash Tool 2.0.2.5 supports both. Check your firmware download — if the file ends in .kdz or .tot, LG Flash Tool can handle it.

What is LGUP and when should I use it instead of LG Flash Tool?
LGUP (LG Update) is a newer LG flashing utility designed for devices running Android 6.0 Marshmallow and above. If LG Flash Tool does not detect your newer LG model, try LGUP instead. Both tools use KDZ files and work in a similar way — the difference is that LGUP has better support for newer LG hardware.

Why won't LG Flash Tool open or launch?
The most common reason LG Flash Tool does not launch is a missing MegaLock.dll file. Download MegaLock.dll and place it in the same folder as the LGFlashTool executable, then try again. Also make sure you are running the tool on a compatible Windows version (Windows 7, 8, 10, or 11).

How do I put my LG phone into Download Mode?
Power off the LG device completely first. Then hold down the Volume Up button and connect the USB cable to the phone while it is still powered off. The phone enters Download Mode automatically. Do not press any other buttons during this step.

Will flashing delete all my data?
Yes — flashing firmware with LG Flash Tool performs a full wipe and restores the device to factory state. All user data, apps, accounts, photos, and settings will be erased. Always back up everything important before starting a flash.

Does LG Flash Tool work without an internet connection?
Yes. After downloading both LG Flash Tool and the correct firmware file, the entire flash process is completely offline. No internet is needed during flashing.

Does LG Flash Tool work on Mac or Linux?
No — LG Flash Tool is a Windows-only application. It is compatible with Windows XP, Vista, 7, 8, 8.1, 10, and 11 in both 32-bit and 64-bit versions. There is no official Mac or Linux version available.

Who created LG Flash Tool?
LG Flash Tool was created and distributed by the LG Vietnam Community. FlashTool.org provides an organized download hub with version history and guides, but full credit for the tool belongs to the LG Vietnam Community.