Assay: Phone Test & Checkup

Assay is a phone tester from Moonlet Labs. Run one guided checkup in about 3 to 5 minutes, or open a single test, then share a plain pass/fail report. Use it before you buy or pass on a used phone, after a drop, or when something seems off.

Check this phone
The guided run takes the tests in a set order. Assay decides by itself where it can, such as the microphone loopback and the sensors, and asks you "Did it work? Yes or No" where only a person can judge. Every step has Skip and Retry; each result is Passed, Failed, Skipped, Not present or Info.

Screen and touch
Full-screen black, white, red, green, blue, 50% grey and a gradient help you spot dots or lines that stay one colour, such as dead or stuck pixels. Paint every cell of a touch grid within 60 seconds to find spots that don't respond, then see how many fingers the screen picks up at once.

Speakers and microphone
Play a tone on the left speaker, the right speaker and both, then the earpiece. Assay raises the media volume for the step and sets it back afterwards. If sound is going to Bluetooth or wired headphones, it asks you to disconnect them first. The microphone loopback plays two tones on the loudspeaker and listens for them. Record and play back lets you hear 3 seconds of your own voice, held in memory and never saved.

Vibration, torch and buttons
Feel the vibration motor, check the torch, and press volume up, volume down and power. Home, Back and Recents belong to Android, so Assay lists them as not testable by apps.

Sensors
Tilt, turn and cover the phone to test the accelerometer, gyroscope, magnetometer, proximity sensor, light sensor and barometer. Each one draws a live trace and passes when the movement shows up. A sensor your phone doesn't have is marked Not present, never as a fail.

Camera, battery and connectivity
Open your camera app to try the front and back cameras; Assay gets no photo and no file. See the battery level, charging status, the health status Android reports, temperature, voltage, technology, the cycle count where the phone reports it, and live charge current while plugged in. Plug in a charger to test charging. See whether Wi-Fi, Bluetooth, NFC, GPS and a fingerprint sensor are present, and whether they are on where Android lets an app see that.

The report
The report lists every result with the date and the device facts: model and manufacturer, Android version and security patch, total RAM and storage, and screen resolution and refresh rate. Add a note of up to 200 characters, then share the report as an image and as text. Every report ends with the same footer, for example: "Self-check made with Assay on this phone on 3 Oct 2026. Results show what the person running it saw and heard. Not a certification. Run it yourself on the phone in front of you."

What Assay can't do
Assay doesn't estimate battery wear or capacity, because Android doesn't give apps that figure. It doesn't look for a GPS signal, scan for networks or devices, read NFC tags or check the SIM. Results show what the person running the test saw and heard.

Privacy
Tests run on your phone. Assay asks for the microphone only at the microphone step: it listens for its own test tone for a few seconds, and the playback test keeps 3 seconds in memory only. Nothing is saved or sent. Your last report is kept on this phone only and is not backed up; you can turn that off or delete it in Settings, and it leaves the phone only when you share it. No account needed, and every test works offline. Results, device facts and notes are never sent to Moonlet Labs. The app is ad-supported: ads are served by Google AdMob, which may use the advertising ID. Moonlet Labs collects crash reports and usage analytics through Google Firebase, linked to pseudonymous app identifiers rather than your name or email; they never include test results. Where the law requires it, the app asks for your consent first, and privacy choices are in Settings. Privacy policy: moonletlabs.com/privacy.html