Deutsche Telekom Speed Test (Europe) — Real Speeds & Fixes

On Telekom, first find your sync rate in the Speedport or FRITZ!Box status page. On VDSL that sync rate is the physical ceiling set by the copper length to the DSLAM, and no test can exceed it. On Glasfaser (FTTH) a wired test should come within about 10% of plan in both directions.

German contracts carry a minimum and a normally-available speed. The Bundesnetzagentur Breitbandmessung desktop app is the measurement Telekom must answer to, so use it to build a case for a price reduction.

Deutsche Telekom (Magenta / T-Online) runs Germany's largest copper and fibre network. Real-world speeds depend heavily on whether you're on Super-Vectoring (250 Mbps copper) or true Glasfaser (FTTH up to 1 Gbps).

Telekom's product at your door depends on the exact address: whether the street cabinet has been upgraded to Super-Vectoring, and whether the Glasfaser build has reached your building and been wired into your flat. In apartment buildings, fibre often stops at the basement until the owner agrees to in-house cabling. Check the address on Telekom's availability checker rather than the postcode.

Plans and realistic speeds

MagentaZuhause M (100 Mbps VDSL): 85-100 Mbps down, 35-40 Mbps up
MagentaZuhause L (250 Mbps Super-Vectoring): 200-250 Mbps down, 40 Mbps up
MagentaZuhause Giga (FTTH 1 Gbps): 880-940 Mbps both directions
MagentaZuhause Giga 2 (XGS-PON): 1.8-2 Gbps wired with multi-gig adapter

Common issues and how to fix them

VDSL syncs at lower than expected: Distance to the DSLAM is everything. Speedport routers show the actual sync rate in the diagnostics page, if it's far below the plan, ask Telekom to check line attenuation.
Speedport Wi-Fi noticeably slower than wired: Speedport Smart 4 is decent, but Wi-Fi 6 mesh kits (FRITZ!Repeater, Eero) handle large flats much better.
MagentaTV stutters at peak: MagentaTV uses dedicated IPTV multicast, if your line is unstable, set-top boxes lose stream first. Wired Ethernet to the box is mandatory for 4K.
Speed is far below the contracted minimum: Record results with the official Breitbandmessung desktop app across at least two days, then cite that log — it is the evidence route German law provides for a price reduction.

Typical latency

Within Germany: 4-14 ms
Frankfurt to Amsterdam: 8-14 ms
Frankfurt to London: 12-22 ms
Frankfurt to New York: 85-105 ms

Wired vs Wi-Fi checks

Read the sync rate from the router status page first — it separates line problems from home-network problems in one step.
Test wired into the Speedport three times and take the median.
Then test Wi-Fi beside the router and in the problem room; FRITZ! or Speedport mesh repeaters address the gap between those two.
Keep MagentaTV boxes on Ethernet before judging any Wi-Fi result, since IPTV multicast competes for airtime.

Reading your result against your plan

VDSL: compare your measured download with the router's sync rate, not the plan name. Measured close to sync means the line is fine and the plan is simply distance-limited.
Super-Vectoring upload is capped around 40 Mbps regardless of download, which is what limits cloud backup on MagentaZuhause L.
FTTH: a wired result under roughly 80% of plan is worth a ticket, since there is no distance penalty on fibre.
Giga 2 requires a 2.5 GbE or faster adapter; through a single gigabit port you will measure about 940 Mbps and nothing more.