Is portable WiFi reliable for broadband? I used it for three months, and after calculating the overstated speed limit, I didn't want to top up a second time

my old house had been empty for half a year, and this summer I'm going back to stay for three months. Install broadband. The installation cost is over 100 yuan, and you still have a two-year contract. If you leave every three months, you have to carry the contract back. If you don't install it, you can't just leech off your neighbors every day. While browsing shopping apps, the "portable WiFi" app popped up—a device for 9.9 yuan, a plan for 39 yuan per month, and the page said "3000GB with no speed limit." I got excited and placed the order. After three months, I'll put all the pitfalls and calculations here.

first distinguish between the three types of portable WiFi. They look different and have different pitfalls. Before ordering

I thought portable WiFi was just one thing, but when I received the product, I realized there are at least three types. If you choose the wrong one, you're wasting money.

The first type is the USB , about the size of a USB drive, powered by a computer when plugged in, costing just a few dozen yuan. It can only supply the computer plugged in to the internet; phones and tablets can't even get light, making it suitable for business trips or laptop emergency use, not even for home use. The second is the battery model, it's palm-sized and comes with a built-in battery, so you can carry it in your pocket. After powering on, your phone and computer can connect it. The one I bought is the one, 130 yuan. The third type, strictly speaking, isn't "portable"—it's CPE. It's box-shaped, fixed with a power plug, large antennas, lots of devices, and follows the "wireless broadband" route, mostly used in dorms and street-facing shops.

there's another common issue hidden beneath these categories: devices with very low prices usually come with IoT SIM cards, not legitimate SIM cards for personal use. I'll talk about card quality later, but remember one thing first—the cheaper the device, the more you need to care about what card it uses. The 9.9-yuan machine is basically a hook.

measured speed: During the day, 35 megabytes dropped to single digits during the evening peak, and base station congestion was unavoidable

I was pleasantly surprised when I first got it. In the old house, the 4G signal is two bars, and the speed test app shows downloads of 35 to 40 Mbps, which translates to just over 4MB/s. Watching videos, opening web pages, and making WeChat video calls is all smooth. I felt like I had struck gold.

backlash starts in the second week. Around 8 p.m., video calls started to blur, speed tests dropped to only 8 to 10 Mbps, download speeds around 1MB/s, 1080P video barely playable, and two people watching simultaneously would spin in circles. By a little after eleven, he had recovered on his own. I kept track for a week: daytime stays steadily around 35 trillion, evening rush hour drops to single digits, and weekends are worse than weekdays.

this 'must be clocked during evening rush hour' is a completely different matter from the landlord broadband I wrote about in urban villages before. The landlord's broadband card is a competition for the same line across the entire building; A portable WiFi card means you compete with everyone in the area for a base station. The base station capacity is only so large, and every household watches videos at night—who does it prioritize? Looking at the dispatch in the telecom city, no one can say for sure, but the result is that your priority is not high. This trap is unsolvable; changing equipment or package plans won't save it. It only depends on the load of the base station in your area.

data account: Rated at 3000GB, speed limits after 100GB. This card is actually only 100G

What really made me lose heart was the data account. The plan page says "3000G per month," and I thought to myself that a family of three would only use 2000 or 300G normally, so 3000G is unlimited. The actual situation is: on the 17th day, when the total data reached just over 100GB, the speed dropped from 35MB straight down to below 1MB, and the webpage took half a day to remove.

contact customer service, and the first round of reply was, 'The backend refreshed for you, try restarting.' Restarting didn't help; The second round says, "Your local base station maintenance"; The third round only revealed the truth—the package has a "fair usage principle" and slows down after reaching the threshold. I asked what the threshold was, and the customer service started doing Tai Chi. I checked the data statistics in the device's backend—100G is the one.

the card's actual specs are: 100G high-speed + 2800G per month at 1 megameter speed. What does 1 trillion mean? WeChat sends and receives text and image lines, video call cards turn into slideshows, and 1080P videos are completely gone. Calculate unit prices to be clearer: how many Mbps is sufficient for your home I calculated that a proper 300 Mbps broadband integrated package costs about 30 yuan a month, unlimited when you want to use it; Portable WiFi costs 39 yuan per month, with actual high-speed data of 100GB. A normal home usage easily gets 200 to 300GB of data per month, which means most of the month struggles with 1 megapixel. The unit price is more than five times higher, so I bought a low-quality version of the internet.

there's another top-up trick to watch out for: the plan page always promotes 'recharge one year, get four months free,' and a little over 300 per year seems like a good deal. But it's normal for merchants in this industry to run away; the longer you recharge, the greater the risk. I'll explain why later.

that card wasn't a mobile SIM card at all: the IoT card couldn't find this number, and the merchant lost the money. After using it for a month

I wanted to try moving the card to my backup phone, but I realized something was wrong: a string of numbers printed on the card board couldn't make calls, texts didn't respond, and none of the official apps of the three major carriers could find any information about this card.

this is the IoT card, abbreviated as IoT card. Originally, it was used to connect devices like shared bikes, charging stations, and POS terminals. Operators distribute them to enterprises, not individuals. If problems arise, operators don't intervene—your contract targets the merchant in the middle, not the operator. This card is also easily used for illegal purposes. When carriers tighten risk controls, they shut down a whole batch, and your top-up money sinks along with it.

searched through complaint cases, and the script was consistent: cheap devices or even free gifts, package top-ups had to be added to the merchant's own app, and after two or three months, the app wouldn't open, customer service disappeared, and the game became bricked. My monthly payment of 39 yuan was still quick to cut losses, but the worst was the annual fee recharge. If you really fall into a trap, keep your recharge records and file a complaint with 12315 or the consumer protection platform. Don't waste time with merchant customer service.

only one turning point: can I insert my own card

In three months, I switched to a second device and figured it out. When choosing portable WiFi, don't be fooled by the looks or the promotional pages about "5G dual-band" or "3000G"—just one thing: can plug in your own card

bundled with package fees (about 9.9 yuan for equipment), if the card is soldered inside and the seller decides, the merchant decides the shots. The three essentials—fake labeling, speed limits, and running away—all depend on the merchant's honesty. For cards that can be inserted, the card slot is open. You can insert your own SIM card or a secondary SIM card. Data can be checked in your carrier's app, and there are channels to complain. If a merchant goes bankrupt, you can remove the card and reuse it elsewhere—the device is just a shell.

my later approach was: I got a secondary SIM and plugged it into the card-inserted portable WiFi, sharing data with the main card. It cost over ten yuan a month, and data is clearly displayed in the carrier's app. If your usage is higher, second-hand platforms can buy a non-locked 4G CPE for just over a hundred yuan. Insert your own card and leave it by the window, and the signal is much better than the battery version. To put it bluntly, equipment can be bought cheaply, but the card must be a under your own name. This sentence is worth the time spent reading.

who really needs it: Take it personally, add a substitute account

to be fair: portable WiFi isn't useless; it saved me from my urgent need, just not suitable as a main tool. Taking the Seat:

calculate alternative options before buying. If you find building a PC troublesome, try adding a high-data secondary SIM to your phone's hotspot. Most hotspots run 30MB without issue, making short-term rentals sufficient and cost-free. If you live somewhere with broadband installed, even if it's a bit more expensive, it's still more comfortable than portable WiFi. If you're worried about contracts, ask if you can pay monthly for broadband; If you live in a rental and want to improve your network yourself, read my article comparing four options before paying.

my ending: At the end of the three-month term, on the day the broadband technician came to install the device, I inserted the portable WiFi card into the drawer and kept it as an emergency backup in case the broadband failed—its last post was the afternoon when the fiber modem was cut off, and it did its job well.