CellRadar
CellRadar guides
Guides about mobile signal, Wi-Fi and internet speed at home and on the go.
- How to check your real signal strength on AndroidTo check signal strength on Android, find the dBm number in your SIM status screen or a signal app. Here is where to look and how to read it properly.
- What does dBm mean? Signal strength numbers explaineddBm measures radio power against one milliwatt. Phone and Wi-Fi readings are negative, and every 3 dB step roughly doubles or halves the power you receive.
- What is a good signal strength in dBm for 4G and 5G?A good signal strength in dBm for 4G or 5G is about −90 dBm or better. Below −100 dBm, data slows down, and below −110 dBm you may start to lose service.
- Full bars but slow internet? Why bars lieFull bars but slow internet usually means a busy cell, interference or a problem beyond the mast. Bars show signal strength, not speed. Here is how to check.
- 4G vs 5G: what you actually get on your phone4G vs 5G on a phone depends on which kind of 5G you get. Low-band 5G feels like good 4G, mid-band is faster, and high-band is very fast but short range.
- Why your phone keeps dropping from 5G to 4G5G dropping to 4G is usually caused by weak 5G coverage, power-saving settings or the network itself. Here is how to find the cause and what you can change.
- How to get better mobile signal at homeTo improve signal at home, find the best spot, use Wi-Fi calling, try another network mode and only use a carrier-approved repeater. Apps cannot boost signal.
- How to find the spot with the best signal in your houseTo find the best signal spot at home, take dBm readings in each room for 30 seconds, compare windows, floors and corners, and note the network type each time.
- Make your own signal map of where coverage is weakA personal signal map is a record of real readings you take on your own routes. It shows where coverage is weak, when it drops and which carrier works best.
- LTE bands and cell IDs explained for normal peopleAn LTE band is the frequency range your phone uses, and the cell ID names the mast and sector serving you. Together they explain your signal and speed.
- Do signal booster apps work? The honest answerNo signal booster app can make your mobile signal stronger. Software cannot change the radio. Here is what these apps really do and what actually helps.
- What a Wi-Fi analyzer shows and how to read itA Wi-Fi analyzer lists nearby networks with their signal, channel, band, width and security. Read the channel graph to see overlap and pick a clearer channel.
- How to find the best Wi-Fi channel for your routerThe best Wi-Fi channel is the one with the fewest strong neighbours. On 2.4 GHz pick 1, 6 or 11; on 5 GHz pick a quiet channel. Use a scan to choose.
- How to change the Wi-Fi channel on your routerTo change the Wi-Fi channel, open the router settings page or app, find the wireless settings for each band, pick a new channel and save. Here is how.
- 2.4 GHz vs 5 GHz vs 6 GHz Wi-Fi: which should you use?In 2.4 GHz vs 5 GHz Wi-Fi, 2.4 reaches further but is slower and busier, 5 GHz is faster nearby, and 6 GHz is fastest and quietest but has the shortest range.
- Wi-Fi 6, 6E and 7 explained: do you need to upgrade?Wi-Fi 6 copes with busy homes, 6E adds the 6 GHz band and Wi-Fi 7 adds wider channels and multi-link. Upgrade only if your devices can use it.
- How to find and fix Wi-Fi dead zonesA Wi-Fi dead zone is a spot where your signal is too weak to use. Find it by walking with a signal meter, then fix it by moving the router, a channel or mesh.
- Where to put your router for the best Wi-FiGood router placement means central, high and in the open, away from metal, water and big appliances. Small moves can make a real difference to your Wi-Fi.
- Mesh Wi-Fi vs a range extender: which fixes your problem?Mesh vs extender comes down to scale. An extender patches one weak room cheaply; mesh covers a whole home with one network and smooth handover.
- How to measure Wi-Fi strength room by roomUse a Wi-Fi strength meter on your phone, take a 30-second dBm reading in each room and add a speed test where it counts. A simple, repeatable method.
- How to run an internet speed test that tells the truthFor an honest internet speed test, pause other traffic, test near the router or on a cable, run it three times at different hours and compare with your plan.
- Download, upload, ping and jitter: what each number meansDownload and upload are speeds in Mbps. Ping is the round-trip delay in milliseconds, and jitter is how much that delay changes. Here is what good looks like.
- Why is my internet so slow? A step-by-step checkWhy is my internet slow? Work out whether it is one device, your Wi-Fi, your router or your provider with this ordered check, from a restart to a line test.
- Fast speed test but slow apps? Here is whyWhen a speed test is fast but apps feel slow, the cause is usually delay, slow DNS, a VPN or a busy app server, not bandwidth. Here is how to find it.
- Is your connection good enough for video calls?The internet speed for video calls is modest, a few Mbps each way for HD, but upload, steady ping and low jitter matter most. Here is how to check yours.
- What internet do you need for online gaming?For online gaming, low and steady ping matters far more than raw speed. Here is what to check, what numbers to aim for, and how to fix lag at home.
- What speed do you need to stream in 4K?Most services suggest roughly 15 to 25 Mbps for one 4K stream. Learn how to check your real speed at the TV and what to fix when 4K keeps dropping.
- How to see who is connected to your Wi-FiCheck who is on your Wi-Fi through the device list in your router or a network scanner app, then match each device by its name, maker and MAC address.
- Found an unknown device on your Wi-Fi? What to doAn unknown device on your Wi-Fi is usually a forgotten gadget. Here is how to identify it calmly, and how to lock it out if it turns out to be a stranger.
- Get an alert when a new device joins your Wi-FiA new device alert tells you the moment something joins your Wi-Fi. Learn your options through the router or a phone app, and how to avoid false alarms.
- Checking a rental for hidden cameras on the Wi-Fi: what a scan can and cannot tell youA hidden camera Wi-Fi scan can show devices on the rental network, but it cannot find every camera. Here is what it reveals and what to check by eye.
- 10 steps to secure your home Wi-FiTen clear steps to secure your home Wi-Fi, from a strong password and WPA3 to router updates, a guest network and checking which devices are connected.
- How to share your Wi-Fi with a QR codeA Wi-Fi QR code lets guests join your network by pointing their camera at it, with no typing. Here is how to make one, share it safely and scan one.
- Where to keep your Wi-Fi passwords safelyThe safest place for Wi-Fi passwords is a Wi-Fi password manager or encrypted vault, not a screenshot or note. Here are good options and ones to avoid.
- Ping and traceroute explained: find where the delay isPing measures the round trip to one server; traceroute shows each hop on the way. Learn how to read both and work out where your delay really starts.
- What DNS is and how a slow DNS feelsDNS turns website names into addresses. When DNS lookup is slow, pages pause before they start loading. Learn the signs, how to test it and what to try.
- What is my IP address, and what can it reveal?Your IP address is the number that identifies your connection online. Learn the public and private kinds, and what it reveals about you and what it does not.
- What an open port is and how to check oneAn open port means a device is listening for connections on that number. Learn how a port checker works, which ports are common, and when to close one.
- How to wake a computer from your phone with Wake-on-LANWake-on-LAN lets your Android phone switch on a sleeping computer with a magic packet. Here is how to set up the computer, the router and the phone.
- Why GPS is weak indoors: satellites and open sky explainedGPS signal is weak indoors because satellite signals are faint and blocked by roofs and walls. Learn how phone location works and how to get a faster fix.
- What a network health score checksA network health check rolls speed, delay, Wi-Fi quality and security into one score. Learn what each part measures and which findings to fix first.
- Why calls drop, and what you can do about itCall drops usually come from weak signal, a failed hand-over between masts or a busy cell. Learn how to find the cause and the fixes that actually help.
- Why signal is weak inside buildings and basementsWeak signal indoors comes from walls, metal, coated glass and soil between you and the mast. Learn which materials block most and what really helps.
- Wi-Fi calling: when to turn it onWi-Fi calling sends your normal phone calls over Wi-Fi when mobile signal is weak. Learn when to turn it on, when to leave it off, and how to set it up.
- Does turning airplane mode on and off fix signal?Toggling airplane mode makes your phone reconnect and pick a cell again, which can fix a stuck connection. It cannot create signal. Here is when it helps.
- How to compare carriers' coverage where you liveTo compare carrier coverage, check official maps, then test each network yourself at home, work and on your commute. Here is how to run a fair test.
- When to call your internet provider, and what to tell themCall your internet provider once you have ruled out your own Wi-Fi and devices. Here is how to tell whose problem it is, and what details to give them.
- Why keeping a signal history helps when you complain to your carrierA signal report with dates, places and dBm readings turns a vague complaint into evidence your carrier can act on. Here is what to log and how to share it.
- Using hotel and café Wi-Fi safelyPublic Wi-Fi safety comes down to joining the right network, using encrypted sites and keeping sharing off. Clear steps for hotels, cafés and airports.
- CellRadar guide: check your signal and Wi-Fi in 5 minutesA five-minute tour of the CellRadar app: read your live 4G or 5G signal, run a speed test, check your Wi-Fi channel and see which devices are on your network.