dB Sound Level Meter & Noise

Now with A, C and Z weighting, IEC 61672 Fast and Slow response, and readings that survive Bluetooth, phone calls and route changes. Free, offline, no subscription.

Most decibel apps show you a number and hope you don't ask questions. This one shows you the number, tells you which scale it's on, and lets you correct it.

WHAT YOU GET

• A, C and Z frequency weighting — with a plain-English explanation of what each one does, right next to the switch
• Fast (125 ms) and Slow (1 s) time weighting, to IEC 61672
• MIN, AVG and MAX for every session, with MAX built to hold short, sharp sounds instead of averaging them away
• A calibration offset you control, ±30 dB, saved between sessions
• HOLD to freeze the display without stopping the measurement
• Session history, with undo on every destructive action

BUILT NOT TO BREAK

• Keeps measuring when you plug in headphones, connect Bluetooth, or switch back to the built-in mic — and tells you when the input changed
• Handles low sample-rate inputs instead of refusing to work. If your Bluetooth headset runs at 16 kHz, the app says so and tells you the frequency range it can still cover
• Comes back on its own after a phone call, an alarm, or a trip to another app. No restart, no lost session
• Measures while your music, podcast or call keeps playing

HONEST ABOUT WHAT IT IS

This is a phone app using a phone microphone. It is not a certified sound level meter. Don't use it where a Type 1 or Type 2 instrument is required, or as the basis for a legal, medical or workplace decision.

The colour zones on the dial are guidance, not a verdict. Readings depend on your device, the microphone in use, and your calibration setting. If the absolute level matters to you, set the calibration offset against a reference meter first — that's what the slider is for.

FREE, AND STAYING THAT WAY

No subscription. No sign-in. No account. No paywalled features. Works with no internet connection at all. Supported by ads.