AVM FRITZ!Box 4020 OpenWrt Firmware
- CPU
- Qualcomm Atheros QCA9561
- RAM
- 128 MB
- Flash
- 16 MB
The AVM FRITZ!Box 4020 is supported by OpenWrt/ImmortalWrt on the ath79/generic target. 4 firmware images are available from the official OpenWrt 25.12.5 and ImmortalWrt 25.12.1 stable releases — download one below, or build a custom OpenWrt image for this device with your own package selection.
Specs
Specifications
| CPU | Qualcomm Atheros QCA9561 |
|---|---|
| CPU cores | 1 |
| CPU frequency | 750 MHz |
| RAM | 128 MB |
| Flash | 16 MB |
| 100 Mbit Ethernet ports | 5 |
| WLAN hardware | Qualcomm Atheros QCA9561 |
| Switch | Qualcomm Atheros QCA9561 |
Hardware data from the OpenWrt Table of Hardware; verify against your unit before flashing.
Build matrix
Supported firmware versions
| Distribution | Version | Target | Profile |
|---|---|---|---|
| OpenWrt | 25.12.5 | ath79/generic | avm_fritz4020 |
| ImmortalWrt | 25.12.1 | ath79/generic | avm_fritz4020 |
Downloads
Download images
OpenWrt 25.12.5 · ath79/generic
| Image | Type | sha256 |
|---|---|---|
| openwrt-25.12.5-ath79-generic-avm_fritz4020-squashfs-sysupgrade.bin Not sure? Pick this if upgrading from OpenWrt. | sysupgrade | 2a4da66cf258… |
| openwrt-25.12.5-ath79-generic-avm_fritz4020-initramfs-kernel.bin Minimal kernel image, useful for first install or recovery. | kernel | e6ef5e79185d… |
ImmortalWrt 25.12.1 · ath79/generic
| Image | Type | sha256 |
|---|---|---|
| immortalwrt-25.12.1-ath79-generic-avm_fritz4020-squashfs-sysupgrade.bin Not sure? Pick this if upgrading from OpenWrt. | sysupgrade | f5d1880c1ed8… |
| immortalwrt-25.12.1-ath79-generic-avm_fritz4020-initramfs-kernel.bin Minimal kernel image, useful for first install or recovery. | kernel | 51df86bfe01b… |
Downloads are served by the official OpenWrt/ImmortalWrt mirrors — unchanged upstream stable builds.
Packages & install
Default packages & installation
Default packages
Every image for the AVM FRITZ!Box 4020 ships these packages by default. The customize option below lets you add or remove packages before the image is assembled.
OpenWrt 25.12.5 · ath79/generic
Device packages (1)
fritz-tffs
Target default packages (29)
apk-mbedtls base-files ca-bundle dnsmasq dropbear firewall4 fstools kmod-ath9k kmod-gpio-button-hotplug kmod-nft-offload libc libgcc libustream-mbedtls logd mtd netifd nftables odhcp6c odhcpd-ipv6only ppp ppp-mod-pppoe procd-ujail swconfig uboot-envtools uci uclient-fetch urandom-seed urngd wpad-basic-mbedtls
ImmortalWrt 25.12.1 · ath79/generic
Device packages (1)
fritz-tffs
Target default packages (33)
apk-openssl base-files block-mount ca-bundle default-settings-chn dnsmasq-full dropbear firewall4 fstools kmod-ath9k kmod-gpio-button-hotplug kmod-nf-nathelper kmod-nft-offload libc libgcc libustream-openssl logd luci mtd netifd nftables odhcp6c odhcpd-ipv6only ppp ppp-mod-pppoe procd-ujail swconfig uboot-envtools uci uclient-fetch urandom-seed urngd wpad-openssl
Installation notes
- Already running OpenWrt or ImmortalWrt: flash the sysupgrade image from LuCI (System → Backup / Flash Firmware) or with the sysupgrade command.
- The kernel / initramfs image boots from RAM without writing to flash — useful for a first install or for recovering from a failed flash.
- Verify your download against the published checksum before flashing:
$ sha256sum openwrt-25.12.5-ath79-generic-avm_fritz4020-squashfs-sysupgrade.bin 2a4da66cf258a8862a585cb4203448e856b59ec1b5d546ce9d24b694e047de51 openwrt-25.12.5-ath79-generic-avm_fritz4020-squashfs-sysupgrade.bin
Build custom firmware
Need more than the default image for the AVM FRITZ!Box 4020? Pick your packages — LuCI apps, themes, VPN clients — set the basics, and get a ready-to-flash OpenWrt image assembled from official packages in minutes.
Customize firmware for this deviceRelated
Related devices
More AVM devices
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- AVM FRITZ!Box 3390 OpenWrt firmware
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- AVM FRITZ!Box 3490 Other NAND OpenWrt firmware
- AVM FRITZ!Box 4040 OpenWrt firmware
- AVM FRITZ!Box 5490 Micron NAND OpenWrt firmware
- AVM FRITZ!Box 5490 Other NAND OpenWrt firmware
More devices on ath79/generic
Upstream
Upstream & source
- downloads.openwrt.org — ath79/generic 25.12.5
- downloads.immortalwrt.org — ath79/generic 25.12.1
- OpenWrt Table of Hardware
Images are assembled from packages compiled and published by the upstream OpenWrt and ImmortalWrt projects. The complete corresponding source code is available from those projects under the GPL.