Find the weak room.

One room is always worse than the others. Sonar tells you which one, and by how much. Stand where the Wi-Fi feels slow and press measure: Sonar reads the radio, times how quickly your router answers and scores the spot out of 100. Do that in a few rooms and you have a survey, weakest first.

How it works

No permission promptsNo adsNo accountNothing uploaded

A Sonar survey of a home, weakest first: the garden table at 34, the back bedroom at 45, the bathroom at 70, then the bedroom and the hallway

The workflow

Measure, compare, send the proof.

Three steps, ten seconds to a minute each. Nothing to set up and nothing to grant.

Measure where you sit

Stand in the room that drops calls and press measure. Sonar samples the link for as long as you choose, from ten seconds to a minute, and records the band it was on.

The Sonar meter at minus 54 dBm on 5 GHz channel 40, set to measure for 20 seconds

Compare the rooms

Name the spot when the measurement ends and file it under a place: home, the office, anywhere else, with the last one you used already picked. Every spot gets a score out of 100, and the list sorts weakest first, because the weakest one is the reason you opened the app.

Sonar results for a home, weakest first: the garden table at 34, the back bedroom at 45 and the bathroom at 70

Send somebody the proof

Export an A4 PDF with every reading, every figure behind it and the conditions it was taken in, or the raw readings as CSV. No watermark, no cap on how many readings go in it.

A Sonar coverage report for a home, eight readings ranked weakest first, ready to share as a PDF

The score

A number you can check, not one you have to trust.

Four measurements go into it, and all four are shown next to it. Out of 100, and higher is better.

Garden tableVery weak34

Back bedroomWeak45

BathroomUsable70

HallwayGood88

StudyExcellent99

What the score is made of

The bathroom's 70, broken down the way the app shows it under every reading.

Signal−73 dBm
Response1.0% lost
Steadinessvery steady
Router link145 Mbps

What you get

The answer, and every number behind it.

A score for every spot

Out of 100, from the signal strength, how steady it stayed, the speed the two radios agreed on and how quickly the router replied.

A live meter in dBm

Signal strength, the band (2.4, 5 or 6 GHz), the channel and the link rate, read once a second. If a reading goes stale the app says so rather than showing you an old number.

A plain answer

Is the Wi-Fi here enough for smart home devices, web and messaging, HD video, video calls, 4K streaming or cloud gaming? Each gets Enough, Marginal or Not enough for this spot, or Not measured when a figure is missing, because Sonar will not guess.

An A4 report

Every reading, ranked, with the conditions each was taken in. A PDF for a landlord or a provider, an image to drop into a chat, or CSV if you would rather do your own sums.

The networks around you

A channel graph of what else is in range and how wide it sits, so you can see who is sharing your frequencies.

No prompt to use it

The meter, the survey, the score and the report all work with every permission switched off. Location is optional and only adds network names and the nearby list.

Screens

Clear on a phone, two panes on a tablet.

Sonar on a tablet: the rooms ranked on the left, and the bathroom's reading open on the right with its verdicts — On a tablet the list and the open reading sit side by side.

The bathroom's reading, 70 and usable: enough for smart home devices and web, marginal for HD video, video calls and 4K, not enough for cloud gaming — Is the Wi-Fi here enough for the thing you actually do?

A channel graph of the Wi-Fi networks in range on 5 GHz, with your own network's two access points listed under it — Who else is sitting on the channel you are using.

The Sonar meter in dark mode, reading minus 56 dBm, strong, on 5 GHz channel 40 — Dark mode, and a meter that never shows you a stale number.

What it does not do.

Sonar measures the link between your device and your router. It is not an internet speed test, and it cannot tell you whether the line into your building is fast, slow or down. If your broadband is the problem, a strong Wi-Fi score will not save you, and Sonar will not pretend otherwise.

It does not change any setting on your router and it will not make your Wi-Fi faster by itself. It tells you where the problem is so that you can.

Nothing leaves your device. There is no account, no analytics, no tracking and no server. Readings are written to the app's own private storage. The only way a measurement goes anywhere is a report you share yourself.

Free, with nothing sold, shown or uploaded.

Android 10 and later. Phones and tablets.