You need a router if you want to use Wi-Fi or connect more than one device
A modem connects you to your internet service provider. A router takes that connection and broadcasts it wirelessly to your devices, or shares it among multiple devices over ethernet cables. If you only have one device and you plug it directly into the modem with an ethernet cable, you do not need a router. If you want Wi-Fi, or if you have a phone, laptop, tablet, and smart TV all trying to use the internet at once, you need a router.
The modem itself does not create a network. It receives the signal from your ISP and converts it into a form your devices can use. Without a router, only one device can connect at a time, and only if you physically plug it in. A router sits between the modem and your devices, managing the traffic and letting multiple things connect simultaneously.
Most households need a router because most people own more than one internet-connected device. Even if you do not care about Wi-Fi, a router lets you plug in a desktop computer, a printer, and a streaming device all at once without unplugging and replugging cables.
Key Takeaways
- A modem alone provides internet to one device via ethernet cable; a router lets multiple devices connect at once and provides Wi-Fi.
- If you have only one device and do not mind using a cable, a router is optional.
- Most ISPs provide a modem only, so you will need to buy or rent a router separately if you want wireless internet.
- Some ISPs offer a combined modem-router unit, which eliminates the need to buy two devices but gives you less control over settings.
- A router also protects your devices by creating a barrier between them and the internet, acting as a basic firewall.
When you can skip the router
If you have a single desktop computer and you are willing to use an ethernet cable, you do not need a router. Plug the cable directly from the modem into your computer's ethernet port. This setup is straightforward and eliminates one piece of equipment to maintain or troubleshoot.
This scenario is rare in practice. Most people own a smartphone, and smartphones do not have ethernet ports. If anyone in your household uses a phone or tablet, you need Wi-Fi, which requires a router. Even if you personally only use a desktop, a guest visiting your home will expect to connect wirelessly.
Direct ethernet connections are sometimes used in offices or server rooms where speed and reliability matter more than convenience, and where every device has an ethernet port. For home use, this setup is impractical for most people.
What happens if you try to use multiple devices without a router
If you plug two devices into a modem using ethernet splitters or by unplugging and replugging cables, the modem will not manage the traffic properly. Most modems are designed to handle one connection at a time. Trying to force multiple devices to share a single modem connection can cause slowdowns, dropped connections, or devices that cannot connect at all.
Wi-Fi does not work without a router. The modem has no Wi-Fi radio. If you want wireless internet, a router is not optional—it is the only way to get it. Some newer modems have Wi-Fi built in, but these are uncommon and usually only available through your ISP as a rental.
Modem-router combo units versus separate devices
Some internet service providers offer a single device that combines a modem and router in one box. Comcast's Xfinity Gateway and similar products from other ISPs are examples. These combo units save space and eliminate one cable, but they come with trade-offs.
Combo units are usually rented from your ISP, which means you pay a monthly fee (typically $10 to $15) for as long as you have service. Buying a separate modem and router costs more upfront but saves money over time if you keep them for several years. Combo units also give you fewer options for customizing Wi-Fi settings, changing security features, or upgrading one component without replacing the other.
If your ISP provides a combo unit and you are satisfied with its performance, keeping it is a reasonable choice. If you want more control, better Wi-Fi range, or lower long-term costs, buying separate devices is usually the better move.
How to choose between renting and buying a router
Most ISPs charge $10 to $15 per month to rent a modem and router. Over three years, that adds up to $360 to $540. A decent standalone router costs $50 to $150 and lasts four to six years. Buying breaks even in about a year and saves money after that.
Renting makes sense if you move frequently, if you do not want to troubleshoot hardware problems yourself, or if your ISP includes technical support for rental equipment. Buying makes sense if you plan to stay in one place for at least two years and you are comfortable replacing a device if it fails.
Check your ISP's rental agreement. Some providers charge extra if you use your own equipment, though this is becoming less common. A few ISPs do not allow customer-owned modems at all, which means renting is your only option.
What to look for in a router if you buy one
Router specifications matter less than they sound. You do not need the most expensive model or the one with the most antennas. Look for a router that supports the Wi-Fi standard your modem and devices use. Most new routers support Wi-Fi 6 (also called 802.11ax), which is fast enough for streaming video, video calls, and gaming on multiple devices at once.
Check that the router has at least four ethernet ports on the back if you plan to plug in devices like a printer or streaming device. Make sure it covers the square footage of your home—most routers cover 1,500 to 2,500 square feet, but larger homes may need a mesh system with multiple units.
Brands like TP-Link, ASUS, Netgear, and Linksys make reliable routers in the $50 to $150 range. Avoid the cheapest models, which often have poor Wi-Fi range and drop connections frequently. Avoid the most expensive gaming routers unless you specifically need the features they advertise.
Frequently Asked Questions
Can I use a modem without a router if I only have one device?
Yes. Plug an ethernet cable directly from the modem into your device. This works fine for a single computer. However, if that device is a smartphone or tablet, it does not have an ethernet port, so you would need a router for Wi-Fi.
Does a router slow down your internet?
A good router does not noticeably slow your connection. A very old or cheap router might reduce speed by 5 to 10 percent, but modern routers are fast enough that this rarely matters. The bottleneck is usually your ISP's speed, not the router.
What if my ISP does not allow customer-owned modems?
You must rent the modem from them. However, you can usually buy your own router and connect it to their modem. This gives you control over Wi-Fi settings and performance without having to buy a modem.
Is it better to rent or buy a modem and router?
Buying saves money over time if you stay with your ISP for more than a year or two. Renting is simpler if you move frequently or want the ISP to handle repairs. Calculate your own situation: monthly rental cost times the number of months you plan to stay, then compare that to the purchase price.
Can I use any router with any modem?
Almost any modern router works with any modem, as long as the modem has an ethernet port. The router does not need to be the same brand as the modem. Check your ISP's website to confirm they do not restrict third-party routers, though most do not.