The simplest way to flash your keyboard will be with the [QMK Toolbox](https://github.com/qmk/qmk_toolbox/releases).
However, the QMK Toolbox is only available for Windows and macOS currently. If you're using Linux (or just wish to flash the firmware from the command line), you'll have to use the [method outlined below](newbs_flashing.md#flash-your-keyboard-from-the-command-line).
Begin by opening the QMK Toolbox application. You'll want to locate the firmware file in Finder or Explorer. Your keyboard firmware may be in one of two formats- `.hex` or `.bin`. QMK tries to copy the appropriate one for your keyboard into the root `qmk_firmware` directory.
The firmware file always follows this naming format:
<keyboard_name>_<keymap_name>.{bin,hex}
For example, the `plank/rev5` with a `default` keymap will have this filename:
planck_rev5_default.hex
Once you have located your firmware file drag it into the "Local file" box in QMK Toolbox, or click "Open" and navigate to where your firmware file is stored.
In order to flash your custom firmware you have to put your keyboard into a special flashing mode. While it is in this mode you will not be able to type or otherwise use your keyboard. It is very important that you do not unplug your keyboard or otherwise interrupt the flashing process while the firmware is being written.
Different keyboards have different ways to enter this special mode. If your PCB currently runs QMK or TMK and you have not been given specific instructions try the following, in order:
* Hold down both shift keys and press `Pause`
* Hold down both shift keys and press `B`
* Unplug your keyboard, hold down the Spacebar and `B` at the same time, plug in your keyboard and wait a second before releasing the keys
* Press the physical `RESET` button on the bottom of the PCB
* Locate header pins on the PCB labeled `BOOT0` or `RESET`, short those together while plugging your PCB in
When you are successful you will see a message similar to this in QMK Toolbox:
First thing you'll need to know is which bootloader that your keyboard uses. There are four main bootloaders that are used, usually. Pro-Micro and clones use CATERINA, and Teensy's use Halfkay, OLKB boards use QMK-DFU, and other atmega32u4 chips use DFU.
You can find more information about the bootloaders in the [Flashing Instructions and Bootloader Information](flashing.md) page.
If you know what bootloader that you're using, then when compiling the firmware, you can actually add some extra text to the `make` command to automate the flashing process.
### DFU
For the DFU bootloader, when you're ready to compile and flash your firmware, open up your terminal window and run the built command:
make <my_keyboard>:<my_keymap>:dfu
For example, if your keymap is named "xyverz" and you're building a keymap for a rev5 planck, you'll use this command:
make planck/rev5:xyverz:dfu
Once it finishes compiling, it should output the following:
```
Linking: .build/planck_rev5_xyverz.elf [OK]
Creating load file for flashing: .build/planck_rev5_xyverz.hex [OK]
Copying planck_rev5_xyverz.hex to qmk_firmware folder [OK]
Checking file size of planck_rev5_xyverz.hex
* File size is fine - 18574/28672
```
After it gets to this point, the build script will look for the DFU bootloader every 5 seconds. It will repeat the following until the device is found or you cancel it.
dfu-programmer: no device present.
Error: Bootloader not found. Trying again in 5s.
Once it does this, you'll want to reset the controller. It should then show output similiar to this:
```
*** Attempting to flash, please don't remove device
0x5600 bytes written into 0x7000 bytes memory (76.79%).
>>> dfu-programmer atmega32u4 reset
```
If you have any issues with this, you may need to this:
sudo make <my_keyboard>:<my_keymap>:dfu
### Caterina
For Arduino boards and their close (such as the SparkFun ProMicro), when you're ready to compile and flash your firmware, open up your terminal window and run the built command:
make <my_keyboard>:<my_keymap>:avrdude
For example, if your keymap is named "xyverz" and you're building a keymap for a rev2 Lets Split, you'll use this command:
make lets_split/rev2:xyverz:avrdude
Once the firmware finishes compiling, it will output something like this:
```
Linking: .build/lets_split_rev2_xyverz.elf [OK]
Creating load file for flashing: .build/lets_split_rev2_xyverz.hex [OK]
Checking file size of lets_split_rev2_xyverz.hex [OK]
* File size is fine - 27938/28672
Detecting USB port, reset your controller now..............
```
At this point, reset the board and then the script will detect the bootloader and then flash the board. The output should look something like this:
```
Detected controller on USB port at /dev/ttyS15
Connecting to programmer: .
Found programmer: Id = "CATERIN"; type = S
Software Version = 1.0; No Hardware Version given.
Programmer supports auto addr increment.
Programmer supports buffered memory access with buffersize=128 bytes.
Programmer supports the following devices:
Device code: 0x44
avrdude.exe: AVR device initialized and ready to accept instructions
Congrats! Your custom firmware has been programmed to your keyboard!
Give it a try and make sure everything works the way you want it to. We've written [Testing and Debugging](newbs_testing_debugging.md) to round out this Newbie Guide, so head over there to learn about how to troubleshoot your custom functionality.
