From this page you can download all firmware versions for your favourite Samsung Galaxy A12 SM-A125F/DSN, SM-A125F/DS, SM-A125F, SM-A125M and SM-A125U. For the before said models you can download the official OTA released firmware.
Please make sure to install the same or higher binary version of your Galaxy A12 firmware other vice you may end up in bricking the device. Also you need to extract the archived file before flashing it using the Odin application for Windows. The firmware version, country, carrier etc need to be confirmed before installing it on your Galaxy A12 Smartphone.
A preface to 3rd party websites downloading process..
In some cases you may need to create a free account and have to login to download the firmware files. Please make sure that you need to select the “Free” option when asked for free downloading.
If you are downloading from SamFrew website first you need to select the country, then carrier and at last the firmware version you need to download.
Now lets proceed to download links!