Decibel Meter App — Free Online, No Install

A decibel meter app usually means a download from an app store. This page is the no-install alternative: a free web app that runs in the browser tab you already have open.

By Bhagya Masalawala · Last materially reviewed: 2026-10-29

Short answer: You can skip the app store: this page is a free decibel meter web app. It shows live dBA, dBC and dBZ estimates with Leq, minimum, maximum, a live graph and spectrum, and exports CSV or JSON — no install, no account, and audio is processed locally, never uploaded. Store apps only outperform it for background logging or offline use, and formal decisions still need calibrated Class 1 or Class 2 hardware.

No install: works in current Chrome, Edge, Firefox and Safari on Android, iPhone, Windows, macOS and Linux.
Free with no account: press Start, allow the microphone, measure — uninstall nothing later.
Uncalibrated readings are screening estimates; calibrate once against a reference for a device-specific offset.

What a decibel meter app actually does

Every decibel meter app — installed or web — does the same job with the same hardware: it takes your device microphone signal, applies A, C or Z frequency weighting, smooths it with Fast (125 ms) or Slow (1 s) response, and shows a sound level in decibels alongside statistics such as an energy-average Leq. The differences between apps are the interface, the extras (logging, saving, reporting) and how honestly they label the uncertainty of an uncalibrated microphone. The measurement physics is below in how the meter works.

Web app versus store app

Browser decibel meter compared with a native store app
Aspect	This web app	Typical store app
Install	None — runs in the tab	App store download
Account	None	Often required for sync
Portrait of privacy	Audio processed locally; pages count usage, never recordings	Varies by app and its permissions
Devices	Any phone or computer browser	One store platform
Updates	Always the current version on reload	Manual app updates
Offline / background logging	Page must be open in the tab	Better fit when supported
Export	CSV and JSON, dB values only when calibrated	Varies

For a one-off measurement on somebody else's phone, a browser page is also the polite option: no install prompt, no storage permissions beyond the microphone, nothing to uninstall afterwards.

What this free decibel meter app includes

Live estimated dBA, dBC or dBZ with Fast and Slow response — pick the answer in dB vs dBA.
Current, minimum, energy-average (Leq) and maximum plus a 240-point graph, following how to use the meter.
A display-only spectrum view, read alongside the dB value in the frequency analyzer guide.
Calibration profiles that make readings device-specific — see how to calibrate.
Up to 20 saved sessions in the browser plus CSV/JSON export — details in microphone privacy.

Accuracy you should honestly expect

No app turns a phone microphone into a certified instrument. Uncalibrated readings are nominal estimates: weighted digital levels plus a fixed offset, which is why two devices in the same room disagree by 5–10 dBA. Phone capsules read too high below about 30 dBA, clip near 95–100 dBA and under-report deep bass. Whole numbers over a 30–60 second average beat chasing decimals — the full limitations are in accuracy and limitations, and a one-time comparison with a known reference is the single biggest upgrade in calibration.

When to choose something other than a browser

A native installed app makes sense for background logging while you do other things, or for measurement conditions with no connection to load the page. A calibrated Class 1 or Class 2 sound level meter operated by a qualified person is required for workplace compliance, court cases or any formal report — see the validation protocol. For everything else — bedroom checks, street noise, speaker comparisons, curiosity — open the live meter and measure now. If levels look worrying, continue with noise limits and noise exposure.

Decibel meter app FAQ

Is there a free decibel meter app?

Yes — this site is one. Open the page, press Start, allow the microphone, and your browser becomes a live decibel meter with dBA, dBC and dBZ estimates, Leq, minimum, maximum and export. There is no install, no account and no fee.

Do I need to install anything on iPhone or Android?

No. On iPhone use Safari, on Android use Chrome (or Edge/Firefox). Grant microphone permission once per origin and measure. A store app is only worth installing for offline storage or background logging while the phone does other tasks.

Are decibel meter apps accurate?

They give screening estimates, not certified readings. Two phones on the same sound commonly differ by 5–10 dBA before calibration; phone capsules also read high near their noise floor and clip near 95–100 dBA. Calibrate once against a known reference for a device-specific offset, and use calibrated Class 1 or Class 2 hardware for formal decisions.

Which is better: a decibel meter app or a web app?

For quick, occasional checks the web app wins: nothing to install, nothing to update, works on any computer or phone, and audio never leaves the device. Choose a native app only if you need background logging or measurements with no internet connection for loading the page.

Does the web meter work offline?

The page loads over HTTPS, so you need a connection once to open it. During a measurement all audio analysis happens locally in your browser, and saved sessions and exports stay on your device.

Use it in your language — no app either way

The web meter is available in seven languages; each guide below is the same browser-based tool with no download:

Open the online decibel meter → · Using your phone as a decibel meter → · iPhone decibel meter →

Try it live

Curious how loud your surroundings are right now? Measure in seconds — no app, no account. Open the live decibel meter →