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FRITZ!Box 6840 LTE Router Review - Performance, Value & Verdict Review


FRITZ!Box 6840 LTE – Performance

6840 LTE 5GHzConsequently the 6840 LTE is more miss than hit so far and we retain the same feeling when it comes to the router’s performance.

On the upside what it does do well is pick up 4G signal. If 4G isn’t in your area it won’t magically make it appear, but where we test we have a very weak 4G signal on our phones and the 6840 LTE picks it up much more strongly. This shouldn’t be a surprise as its antennas are significantly larger and are not fighting with GPS, Bluetooth and all manner of other smartphone internal antennas, but it is a major selling point for the router.

The problem is while its LTE signal reception was good, its wireless performance is woeful. At our test distances of 2m and 10m line of sight and 15m behind two standing walls the router’s 802.11n 5GHz performance hit just 12.1MBps (96.8Mbps), 7.6MBps (60.8MBps) and 6.22MBps (49.76Mbps).

Aside from its 15m speed this is performance we would expect to see equalled, if not bettered, by 802.11n 2.4GHz performance and we spent some time checking and re-checking that the router had not got stuck on the 2.4GHz band. How we discovered that it hadn’t (after several reboots and resets) was by testing the router’s 802.11n 2.4GHz performance.

6840 LTE 2.4GHzHere the 6840 LTE managed just 8.64MBps (69.12MBps), 4.42MBps (35.36Mbps) and 1.73MBps (13.84Mbps). Quite frankly this is rubbish and slower than anything we have seen from the worst ISP-supplied home routers like the Sky Hub or PlusNet’s TG582n and the miserable picture was completed with lacklustre 1.7MBps (13.6MBps) performance over USB.

Those jumping to the defence of the 6840 LTE will say that 4G speeds are unlikely to get much faster than the router’s performance at 2m and 10m, but that ignores both the 15m results and the fact this is meant to be a router which can replace your fixed home broadband connection.

The irony is in getting strong 4G reception, it achieves the tough bit but then completely fluffs its lines with dreadful WiFi performance and a lack of simultaneous dual band operation.

6840 LTE 3

Should I buy the FRITZ!Box 6840 LTE?

By now you will know the answer is a definite ‘no’ and that becomes a ‘NO!’ when you realise AVM is asking a mind boggling £255.70 for this router – more than any other router we have tested. We contacted AVM to query this and were told the LTE element of the router adds a significant premium. It may do, but D-Link’s LTE router, the DWR-921, retails at £140.

Furthermore there are simply better ways to get 4G into your home. A 4G MiFi from Three, for example, can be purchased for £70-80. It delivers similar 802.11n wireless performance and has an integrated battery so it can be carried around. If the MiFi’s wireless performance isn’t strong enough then buy the D-Link DIR-880L – the fastest 802.11ac router we have tested to date – for £130 and use it in Bridge Mode. You will have two top notch devices, vastly better wireless performance, a mobile 4G and £45 still in your pocket.


With the FRITZ!Box 6840 LTE AVM is trying to branch out into new territory and it is to be applauded for doing so. The problem is it has got very little right. The looks are fine and the 4G antenna is strong, but the setup and wireless performance leave a lot to be desired while the asking price is ridiculous. We’d like to say there’s potential for a great second generation product, but in reality the usually reliable AVM needs to throw away everything and go back to the drawing board.

Next, check out our pick of the Best Routers

Trusted Score

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Score in detail

  • Performance 4
  • Value 3
  • Features 6
  • Build Quality 7
  • Usability 4
  • Design 6

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