Can a phone measure decibels? Best dB meter apps 2026

Yes, within limits. Published lab studies by NIOSH found the best iPhone sound meter apps read within about ±2 dB(A) of a reference meter, and within ±1 dB with a calibrated external microphone. Android results varied more. That is good enough to spot risky noise, not to replace a certified meter. On public store data, the top picks are NIOSH Sound Level Meter (iPhone), NoiseLedger (iPhone and Android) and Decibel X.

Comparison at a glance

#	App	Score	Price	Ads	Subscription	Tracking / linked data	Android trackers	Last update	Get it
1	NIOSH Sound Level Meter EA LAB (for NIOSH/CDC)	10.0	Free	No	None	tracking: No, 0 linked	Not stated	2026-10	App Store
2	NoiseLedger: Decibel Meter ◆ Lapnito.cz s.r.o.	10.0	Free	No	None	tracking: No, 0 linked	Not stated	2026-08	App Store · Google Play
3	Decibel X: dB Sound Level Meter SkyPaw Co., Limited	8.2	Free	Yes	Optional	tracking: No, 0 linked	Not stated	2026-10	App Store · Google Play
4	Sound Meter rootApps	6.8	Not stated	Yes	Not stated	Play: Yes	Not stated	2026-08	Google Play
5	phyphox RWTH Aachen University	6.7	Free	Not stated	Not stated	tracking: No, 0 linked	Not stated	2026-09	App Store · Google Play
6	Decibel Meter Pro Performance Audio	5.6	Not stated	Not stated	Not stated	Not stated	Not stated	Not stated	App Store
7	Sound Decibel Meter Splend Apps	5.1	Not stated	Yes	Not stated	Play: No	Not stated	2026-08	Google Play

Scores (0–10) come from our published methodology and are calculated without the developer's name. Facts are read from store listings, privacy labels and Exodus Privacy reports on the verification date.

Disclosure: apps marked ◆ are made by lapnito.cz s.r.o., the company that runs this site. They were scored with the same methodology as every other app, without the developer's name, and the ranking is published unchanged (here: position 2 of 7).

What a phone can and cannot measure

A phone microphone is built for speech, not for acoustic measurement. It has automatic gain and noise processing that apps must work around, and every phone model sounds a little different. That is why the same app can read differently on two phones, and why calibration matters.

The best-known evidence comes from NIOSH, the US occupational safety institute. In a 2014 study published in the Journal of the Acoustical Society of America, Kardous and Shaw checked smartphone apps against a professional reference in a sound chamber. Only 10 of more than 130 iOS apps and 4 of 62 Android apps met their selection criteria. The best app averaged −0.52 dB from the reference with A-weighting, and two others stayed within ±2 dB. A 2016 follow-up found that calibrated external microphones brought readings within ±1 dB and reduced variability.

A 2025 systematic review of 17 studies and 42 apps (Yew et al., Medicine and Health UKM) reached the same picture: iOS apps were generally more accurate than Android apps, external microphones beat built-in ones, and newer phones did better.

What a phone cannot do:

It does not meet the IEC 61672 class 1 or class 2 standard for sound level meters. NIOSH says its own app does not comply with any national standard and is not a replacement for a professional meter or dosimeter.
Very loud sounds can overload the microphone, and very quiet rooms are below what many phone microphones resolve well.
It cannot give you a legally valid reading for a workplace assessment or a dispute with a neighbour.

What it can do well: tell you whether a concert, workshop or nursery is roughly at 70, 85 or 100 dB(A), and log noise over time so you can see patterns.

How we picked

We defined the job first: a person who wants a useful dB(A) reading and a record of it. That gives five required features: A-weighting, calibration (an offset you can adjust), an average or Leq value, a maximum level, and export of measurements. A feature counts only when the App Store or Google Play listing names it.

We then read the public store listings, Apple privacy labels and Google Play Data safety sections for seven popular sound meter apps on 6 November 2026. We did not install or measure with any of them. The ranking below comes from our blind scorer, which removes app names and developers before weighing features, privacy, cost, ads, maintenance and permissions. NoiseLedger is made by lapnito.cz s.r.o., the company that runs this site; it was scored by the same rules.

1. NIOSH Sound Level Meter (iPhone)

The app NIOSH developed with EA LAB is free, has no ads, no in-app purchases and an Apple privacy label that says no data is collected. Its listing covers A, C and Z weighting, LAeq and time-weighted average, max and peak values, noise dose against NIOSH and OSHA limits, calibration for the built-in or an external microphone, and PDF or HTML reports.

Best for: workers, safety reps and anyone on an iPhone who wants the most documented option. Limit: iPhone and iPad only; NIOSH says it could not verify accuracy across the many Android devices.

2. NoiseLedger: Decibel Meter (iPhone and Android)

NoiseLedger, a Lapnito app, is free with no ads and no subscription according to its listings, and both the Apple privacy label and Play Data safety report no data collected. The listing names A, C and Z weighting, min, Leq and max values, a calibration wizard with offsets for many iPhone models, a dosimeter, a spectrogram, overnight recording and CSV, PNG or PDF export. It is stated to work fully offline without an account.

Best for: Android users who want the NIOSH-style feature set, and people who log noise over a night or a week. Limit: it is a young app with few store ratings, so there is less public feedback than for the others.

3. Decibel X (iPhone and Android)

Decibel X by SkyPaw is one of the most rated sound meters, with more than 160,000 App Store ratings. Its listing covers A, B, C, Z and ITU-R 468 weighting, Leq and max values, a calibration trim, an FFT spectrum, a dosimeter and CSV or PNG export, plus Apple Watch support.

Best for: people who want a polished app on both platforms and do not mind paying. Limit: the Google Play listing shows ads, there is an optional subscription, and the App Store purchase list includes separate weighting and data-export add-ons, so some listed features may cost extra.

4. Sound Meter by rootApps (Android)

This Android app has a gauge, a graph, min, average and max values and per-device calibration. Best for: a quick reading on Android. Limit: it contains ads, Play Data safety says some data is shared with third parties, and the listing does not mention A-weighting or export.

5. phyphox (iPhone and Android)

phyphox from RWTH Aachen University is a free physics lab app that reads many phone sensors, including the microphone, and exports data to CSV or Excel. Both stores report no data collected. Best for: students and teachers running experiments. Limit: it is not a dedicated sound level meter; the listing does not mention dB(A), calibration or Leq.

6. Decibel Meter Pro (iPhone)

Decibel Meter Pro by Performance Audio lists A, B, C and Z weighting, calibration and a max readout. Best for: iPhone users who want a simple meter. Limit: its privacy label gives no details, and we could not confirm the current price or last update from public pages, which lowered its score.

7. Sound Decibel Meter by Splend Apps (Android)

A very popular, simple Android meter with a dB readout and a graph. Play Data safety reports no data collected or shared. Best for: a casual check of how loud a room is. Limit: it contains ads, and the listing names none of our five required features.

When not to use an app

Use a certified class 1 or class 2 sound level meter, or a personal noise dosimeter, when the reading has consequences: an occupational noise assessment, a planning or nuisance complaint, a hearing conservation programme or a legal dispute. In the EU, Directive 2003/10/EC sets action values at 80 and 85 dB(A) and an exposure limit of 87 dB(A) over an 8-hour day; employers must assess exposure with suitable equipment. If you already notice ringing in your ears or muffled hearing after noise, see a doctor or an audiologist rather than relying on an app.

FAQ

Are decibel apps on iPhone more accurate than on Android?

In the published studies, yes on average. NIOSH linked this to the audio capabilities of iOS and to the fragmentation of Android, where thousands of models use different microphones. A good Android app with calibration can still give useful readings.

How do I calibrate a sound meter app?

The reliable way is to compare against a calibrated sound level meter or an acoustic calibrator and set the app's offset so both agree. Without one, use the app's built-in model offsets if it has them and treat readings as approximate.

Do I need an external microphone?

Not for a rough check. For work where ±1 dB matters, NIOSH recommends a calibrated external measurement microphone, which brought readings within ±1 dB of a reference in its studies.

What is dB(A) and why does it matter?

dB(A) is a sound level adjusted to match how human hearing responds to different frequencies. Hearing-risk limits, including the EU 80, 85 and 87 dB(A) values, are given in dB(A), so look for an app that offers A-weighting.

Can an Apple Watch or phone warn me about loud noise?

Apple Watch has a built-in Noise app that can warn about loud environments, and the NIOSH app can save readings to Apple Health. These are useful warnings, but they are not certified measurements.

What changed

2026-11-06: First version.

Can your phone measure decibels accurately? What studies show, and the best apps