The firmware
From an empty card to a running radio in about twenty minutes: download the image, write it to a microSD card with balenaEtcher, put it in the radio and switch on. From v0.127 the next versions also arrive over WiFi, without the microSD.
Writing the image erases the whole card, including the DATA partition with settings, logs, memories and pictures.
Before you start, open the radio's web page in a browser (http://<radio IP>/), go to
Backup and download the file. After the update, load it back from the same page and choose what to restore.
Log in to your account (it's free) and download the SD image of the latest version:
a file called X6100-IU1WXY-v<version>-sdcard.img.zip, about 100 MB. No need to unzip it,
balenaEtcher reads it as it is.
.img.zip file you downloaded.Raspberry Pi Imager or Rufus work too, or dd on Linux.
If your radio already runs v0.127 or newer, a version that changes only the radio's interface and apps, and not the system underneath (kernel, drivers, libraries), can arrive over WiFi: no card to take out, no computer. A version that also changes the system, like 0.127, has to be written to the microSD, and the update says so. The radio stays on, its screen restarts once for 10-20 seconds, and settings, logs, memories and pictures stay where they are. If something goes wrong, the radio goes back to the version it had by itself: nothing is lost.
The Versions page says for each version whether it comes this way (app update, no flashing) or needs the card rewritten (full image needed).
Before you start: the radio is on and connected to WiFi, on the same network as your phone or computer.



In short: CHECK → DOWNLOAD → INSTALL. If the new version needs the card rewritten, the button becomes DOWNLOAD IMAGE and opens the Versions page. FROM FILE is only for a package you got some other way. The file left in Download is also the one to copy by hand, see below.
If the radio is connected to the internet (WiFi or Ethernet cable) it can update without phone or computer.

Over the radio's WiFi the download can take a few minutes; with the Ethernet cable it is quicker.
x6100-app-<version>.tar.gz on your computer.http://<radio IP>/. The IP is in Settings → Wireless.
update folder (create it if it isn't there).
Don't unzip it.update/done. If it couldn't be installed it goes to
update/failed, next to a short text file that says why.Settings → Update shows the firmware version and, next to it, the system: System 1. The system changes only when a version needs the card rewritten.
The app, the web page and the radio use the same words. What they mean and what to do:
x6100-app-…tar.gz file, not the SD image (.img.zip).The steps at the top of this page always work, whatever version the radio has. The update without the microSD is experimental: if a problem ever comes up, rewriting the card always fixes it. Write the card:
Writing the card starts clean: it erases everything on it, settings, logs and pictures included. If the radio still works, download the Backup from its web page first and load it back afterwards.
Switch the radio off and take the microSD card out: next time it starts with the Xiegu firmware. To come back to this firmware, just put the card back in.
Something wrong? Report it here. Everything else is in the guide.