We Burned 100GB on Six 'Unlimited' Plans. The First Throttle Hit on Day 12.

Unlimited is a marketing word. We bought six unlimited phone plans, loaded each into the same unlocked phone model, and burned 100GB per line over 21 days. We ran speed tests every 30 minutes from 7 a.m. to 11 p.m. in Austin, Phoenix, and a rural route outside Columbus. No carrier knew we were testing. No freebies, no review units, no sponsored SIMs. We measured the speed before the slowdown, the speed after, and the day the first throttle hit.

The test setup

We used the same test server for every speed check and logged download speed, upload speed, and latency. We streamed video at the highest available setting, uploaded photo batches, and ran hotspot sessions on a laptop. We also read the network management section of each plan, which is where the real limits live. The advertised price was the least useful number in the entire test.

The throttle table

Carrier A cost $70 a month and slowed us after 50GB, from an average of 210 Mbps to 85 Mbps. Carrier B cost $55 and slowed after 35GB, from 180 Mbps to 0.128 Mbps. Carrier C cost $45 and slowed after 50GB, from 95 Mbps to 3 Mbps. Carrier D cost $35 and slowed after 20GB, from 65 Mbps to 0.128 Mbps. Carrier E cost $60 and slowed after 75GB, from 160 Mbps to 1.5 Mbps. Carrier F cost $80 and did not hard-throttle until 100GB, but it deprioritized us after 75GB, dropping from 190 Mbps to 45 Mbps during busy hours. Carrier D hit its cap on day 12. That was the first throttle in the test.

What 'unlimited' actually means

There are two different punishments. Deprioritization means your data still works, but you go to the back of the line when the tower is busy. Throttling means your speed is cut to a fixed number, sometimes as low as 128 kilobits per second. At that speed, maps load slowly and video is not happening. Several plans also managed video to 480p by default, which is a soft cap on quality even when the speed test looks fine. Hotspot data was capped separately on four of the six plans, usually at 5GB or 10GB.

The real cost per usable gigabyte

Carrier D looked like the bargain at $35 a month. But 20GB of high-speed data works out to $1.75 per usable gigabyte. Carrier B was $1.57 per usable gigabyte. Carrier C was $0.90. Carrier E was $0.80. Carrier F was $0.80 until the 100GB mark. If you use 15GB a month, Carrier D is fine. If you use 80GB, Carrier D is a trap. The cheap plan is only cheap if you stay under the cap.

Who won

Carrier E had the best balance for our test. It gave us 75GB of high-speed data, then a usable 1.5 Mbps, for $60 a month. Carrier F was the best choice for a heavy user who needs speed after 75GB, but the $80 price is real. Carrier C was the best middle option for a single-line user who streams music and checks email. Carrier D was the worst for anyone who thinks 'unlimited' means 'use it like Wi-Fi.' Carrier A was expensive but stable. Carrier B was fast until it was not, and the drop was brutal.

How to shop without getting burned

Read the network management section before you buy. Look for the words 'deprioritized,' 'throttled,' and 'video management.' Check the hotspot cap separately. Ask what happens after the cap, not just what the cap is. Then run a trial on the carrier's network in your own apartment. The best unlimited plan is not the one with the biggest number in the ad. It is the one that still works when you actually need it.