Flashtool 0.9.18.6 May 2026

Flashtool v0.9.18.6 is a legacy version of the popular open-source utility used to flash firmware on Sony Xperia

Watch the magic happen: The log window will turn green and show:

23/05/2023 14:32:17 - INFO  - Device connected in flash mode
23/05/2023 14:32:19 - INFO  - Reading device information
23/05/2023 14:32:25 - INFO  - Flashing system.sin

Wait 5–15 minutes depending on firmware size (system.sin is the largest).

When complete, you’ll see: Flashing finished. Please unplug and start the phone.

Disconnect the USB cable and power on the phone. The first boot may take 10+ minutes.

Run C:\Flashtool\FlashTool64.exe (for 64-bit systems) or FlashTool.exe (32-bit).
Allow the tool to update its device database if prompted (this is safe).

Backup your TA partition first.
Use a good USB 2.0 cable.
Run as Administrator on Windows.
Never disconnect during system.sin flashing.

Unlocking bootloader

Click OK, then follow prompts to put device into Flashmode:

Step 3: Install the Drivers (Crucial)

Flashtool update (0.9.19.0) adds support for 2015 Xperia models flashtool 0.9.18.6