Once you have the right firmware, optimize it:
Verdict: Stick with Official OpenWrt for the v5. It gets weekly security updates.
Beyond the technical thrill, the MR3420 v5 firmware scene highlights a growing trend in electronics: sustainability. tp-link mr3420 v5 firmware
Instead of discarding a perfectly functional router because the manufacturer stops updating it, flashing new firmware extends the device's lifespan by years. It turns e-waste into a utility.
Do not buy the MR3420 v5 expecting WiFi miracles. The 2.4GHz radio is fine for IoT, and the 5GHz (AC750) is mediocre. The real value is the USB port + 4G modem combo. Once you have the right firmware, optimize it:
Keep a backup: Before flashing anything, download the stock firmware from TP-Link and use the dd command or a hex editor to backup your original ART (Atheros Radio Test) partition. Once that’s gone, your calibration data is gone forever.
Have you bricked your v5 or successfully flashed OpenWRT? Drop a comment below. Let’s help each other keep this cheap, rugged router out of the landfill. ⚠️ Warning : Stock firmware disables USB tethering
Disclaimer: Flashing third-party firmware voids your warranty and may brick your device. Always verify the MD5 hash of your firmware file.
⚠️ Warning: Stock firmware disables USB tethering for some newer Android/iOS phones. If that happens, consider OpenWrt.
After testing stock v1.4.0 vs. OpenWRT 23.05.2:
If you use this router for gaming, flash OpenWRT. The bufferbloat on stock firmware is terrible (adding +150ms latency under load). OpenWRT’s SQM reduces that to +15ms.