HowLoudThe Best Decibel Meter Apps in 2026, Compared
Disclosure: we make HowLoud, so it is not a neutral pick. We have tried to be fair: every fact about the other apps below comes from their own App Store listings in October 2026, and we say where they beat us.
Best for most people: HowLoud, a free meter with real A-weighting, session history and a one-time $4.99 upgrade for PDF reports, with no ads, no subscription and no data collected. Best free and most validated: NIOSH Sound Level Meter (iPhone only). Most features: Decibel X, if you are happy with a subscription. Best pro toolkit: Decibel: dB sound level meter, with spectrum analysis and a dosimeter as paid packs.
At a glance
| App | Platforms | Price model | Data collected (App Store label) | Best for |
|---|---|---|---|---|
| 1. HowLoud | iPhone, Android, web, browser extension | Free; one-time $4.99 for PDF reports and 90-day history | Data Not Collected | Everyday measuring, noise diaries, reports |
| 2. NIOSH Sound Level Meter | iPhone only | Completely free, no in-app purchases | Data Not Collected | Workplace exposure checks |
| 3. Decibel X | iPhone, Android | Free tier; membership $1.99/week, $5.99/month or $49.99/year; add-ons $1.99–$2.99 | Usage Data, Diagnostics (not linked to you) | Feature depth, many weightings |
| 4. Decibel: dB sound level meter | iPhone, Android | Free tier; packs $9.99–$24.99 or $49.99 lifetime | Includes Location, Identifiers, Purchases, linked to you | Spectrum analysis, audio set-up |
Prices are US App Store prices on 3 October 2026 and change by country and over time.
How we ranked them
We ranked for a typical person who wants to know how loud something is, keep a record and maybe show it to a landlord, council or doctor. Five things decide that:
- Measurement quality: unprocessed microphone audio and real A-weighting, Leq averaging, calibration.
- Fair price: one-time purchases beat weekly subscriptions for a tool you use now and then.
- Privacy: a meter has no reason to collect your location or identifiers for anyone but you.
- Records: saved sessions and a report you can hand to someone.
- Reach: works on the devices you and the other person have.
Why these criteria matter is covered in how accurate a phone decibel meter is and dBA vs dBC.
1. HowLoud – Decibel Meter
HowLoud is built around one screen: a large live dB(A) number over a coloured "fluid" that rises with the level, with min, average (Leq) and peak below. It uses an IEC 61672-1 A-weighting filter and the standard Fast time weighting, and you can set a calibration offset if you have a reference meter. Sessions save with date, duration, chart and the place you measured.
- No subscription. Measuring, statistics, charts and seven days of history are free; a single $4.99 purchase unlocks PDF reports and 90-day history.
- PDF noise report: A4 document with stats, time chart and a mini-map, ready for a complaint.
- Everywhere: iPhone and Android apps, the same meter in the browser and as a Chrome, Firefox and Edge extension, plus a classroom mode on the web.
- Private: no account, no ads, no analytics in the app; App Store label "Data Not Collected".
Where it falls short: HowLoud is new and has almost no App Store ratings yet, where the others have tens of thousands. It has no spectrum analyser, no octave bands and no dosimeter, so audio engineers and safety officers will want one of the apps below.
2. NIOSH Sound Level Meter
Made by the US National Institute for Occupational Safety and Health with acoustics engineers, this is the most credible free meter there is. Its listing states accuracy validated to ±2 dBA against standards on supported iPhones, and it is completely free with no ads, no limited features and no in-app purchases. It reports occupational measures such as TWA and noise dose as well as LAeq and peaks, and it is rated 4.7 from about 17,000 reviews.
Why it is not first: it is iPhone only, its interface is built for safety professionals rather than everyday questions, and it does not make a shareable noise report with a map. If you are on an iPhone and your question is "is my workplace safe", use it.
3. Decibel X: dB Sound Level Meter
The most popular meter on the App Store, rated 4.6 from about 160,000 reviews, on iPhone and Android. It is packed: frequency weightings including ITU-R 468, spectrum and spectrogram views, response-time options including Impulse, and calibration. Its latest update notes say ads were removed for all users.
Why it is third: the full app is a membership at $1.99 a week, $5.99 a month or $49.99 a year, and some features are separate add-ons ($1.99 weightings, $2.99 data export). Its privacy label lists usage data and diagnostics collected, not linked to you. Great if you use it professionally every week; expensive for an occasional noise check.
4. Decibel: dB sound level meter
A serious toolkit from a long-running developer, rated 4.6 from about 36,000 reviews, with a well-known blog of "how loud is" explainers. The free meter is solid, and paid packs add an FFT spectrum analyser, spectrogram and octave RTA ($24.99), A/C/Z weightings with saving and export ($19.99), and a background noise dosimeter ($9.99), or everything for $49.99.
Why it is fourth: getting the full set costs the most of the four, and its App Store privacy label is the broadest: data linked to you includes location, identifiers and purchases. For audio set-up and studio work the analyser is excellent; for a noise diary it is more than you need.
Which should you pick?
- You want to know how loud it is and keep a record: HowLoud.
- You need to check workplace exposure on an iPhone, for free: NIOSH Sound Level Meter.
- You need every weighting and a spectrogram and don't mind a subscription: Decibel X.
- You tune speakers or rooms and want an analyser you pay for once: Decibel: dB sound level meter's lifetime pack.
- You only need a quick reading on a laptop: no app at all, use the online decibel meter.
Whatever you choose, remember that no phone app is a certified instrument. For a legal dispute you will need a Class 1 or Class 2 sound level meter.
Frequently asked questions
What is the most accurate decibel meter app?
The NIOSH Sound Level Meter has the strongest published validation, ±2 dBA on supported iPhones. Most good apps, HowLoud included, land within about ±3 dB after calibration; accuracy depends more on the phone's microphone than on the app.
Is there a free decibel meter app with no ads?
Yes. NIOSH Sound Level Meter is entirely free with no ads. HowLoud is free to measure with no ads; only PDF reports are a one-time purchase.
Which decibel meter app works on Android?
HowLoud, Decibel X and Decibel: dB sound level meter all have Android versions. NIOSH Sound Level Meter is iPhone only.
Do I need to pay for a decibel meter app?
Not for measuring. You pay for extras: saved history, exports, reports, spectrum analysis. Prefer one-time purchases unless you use the extras every week.