When fibre hasn't arrived, or when internet is only needed temporarily, a SIM-based device is the quickest solution. Online stores offer hundreds of options with overlapping names.
Two things determine your satisfaction, and sellers rarely discuss either: the right device form, and frequency band support.
MiFi or 4G router
| MiFi | 4G router | |
|---|---|---|
| Power source | Battery | Mains |
| Connected devices | 8–16 | 32–64 |
| Antennas | Internal, small | Larger, often expandable |
| LAN ports | None | Present |
| Wi-Fi coverage | One room | A small house |
| Price range | Rp 300k – 900k | Rp 600k – 2.5m |
| Suits | Travel, temporary use | Daily home internet |
The simple rule: if the device will stay in one place and run all day, choose a 4G router. A MiFi can be used continuously, but two consequences are often left out of the calculation.
Its battery ages faster when left permanently plugged in, and on some models a swollen battery pushes the casing apart. If you do want to use a MiFi as a stationary device, look for a model that runs with the battery removed.
Its antennas are limited. A compact size means little antenna space, and that shows immediately in locations where signal is marginal.
The decisive part: band support
This is the number one cause of a device that "gets no signal when a phone does", and no setting can fix it.
Carriers transmit across several frequency bands at once, and the allocation differs between regions. A device supporting only some bands will work well in one city and poorly in another.
Bands commonly used for 4G in Indonesia include Band 1, 3, 5, 8, 40, and 41. What to do before buying:
- Check the band list in the product description. If the seller doesn't list them at all, that in itself is a signal.
- Match it against the carrier you'll use in that area.
- Avoid uncertified imports. Beyond mismatched bands, the warranty doesn't apply — discussed in the guide to telecommunications equipment certification.
Be wary of devices priced far below market. That gap almost always comes from trimmed band support, an older modem generation, or second-hand units locked to a foreign network. Devices like these can't be salvaged even with an added antenna.
Reading LTE categories
| Category | Theoretical ceiling | Notes |
|---|---|---|
| Cat4 | 150 Mbps | Already exceeds real speeds in most locations |
| Cat6 | 300 Mbps | Useful in cities with device-dense networks |
| Cat12 and above | 600 Mbps+ | Rarely used to capacity in Indonesia |
Like the numbers on a Wi-Fi router's box, the category is a theoretical ceiling — not a speed promise. In practice, what matters more is signal quality where the device sits.
For most homes, Cat4 with full band support delivers better results than Cat12 with limited bands.
Placing and testing
The difference between a desk and a windowsill is often several-fold. A few minutes moving the device around delivers an improvement money can't buy.
Open the device panel and find the signal figures
Look for RSRP and SINR, not the bar count. RSRP above -100 dBm counts as good; SINR above 10 dB indicates a signal clean of interference.
Try several spots
Near a window, an upper floor, and the side of the house facing the nearest tower. Note the figures at each point rather than going by impression.
Test at peak hours
Eight to ten in the evening is the real test. Daytime results are often far better and misleading — the internet speed test guide.
When an external antenna is worth it
If the best RSRP you can achieve is still below -105 dBm, an external antenna usually delivers a bigger improvement than replacing the device.
One requirement: the device must have external antenna connectors — usually marked TS-9 or SMA behind a small cover. A device without them cannot be upgraded at all, and this is worth checking before buying.
Installation follows the same principles as any antenna: as high as possible, aimed at the nearest tower. For locations genuinely beyond coverage, the remaining options are discussed in the guide to satellite internet.
On SIMs and allowances
The device is only half the story. A few things worth checking:
- Dedicated home-device plans are usually cheaper per gigabyte than phone plans, but sometimes lock the SIM to one specific device.
- Fair use limits are almost always present even when marketed as unlimited. Ask for the figure in writing.
- Upload speed on mobile networks is generally much lower than download. If you attend online meetings often, check this first.
If the need is permanent
For home internet used daily and long term, two comparisons deserve consideration before deciding.
A carrier's 5G home plan generally delivers better results than assembling your own 4G router with a prepaid SIM — the hardware is matched to their network, and the plan is designed for home use. Its comparison against fibre is in the guide to 5G home internet vs fibre.
And if fibre is actually available at your address, it's almost always the better choice for permanent use. Mobile devices shine most in their other role: temporary internet, and a backup line when the cable fails.
Frequently asked questions
What's the difference between a MiFi and a 4G router?
A MiFi runs on a battery, is compact, and is designed to be carried — suited to travel and a few hours of use. A 4G router runs on mains power, has better antennas, LAN ports, and can serve far more devices all day long.
Is a MiFi enough for everyday home internet?
For one or two people with light usage, usually yes. For a family with a smart TV and several phones, a MiFi will struggle — its maximum device count is small and its battery ages faster when permanently plugged in.
What do LTE categories like Cat4 or Cat6 mean?
The category indicates the device's theoretical speed ceiling. Cat4 reaches around 150 Mbps, Cat6 around 300 Mbps. For most locations in Indonesia, Cat4 already exceeds what's genuinely available in practice.
Why do cheap devices sometimes get no signal when a phone does?
Because the device doesn't support all the frequency bands your carrier uses in your area. This is the most common problem with uncertified imported devices, and no setting can fix it.
