OpeNoise vs CJDecibel
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
OpeNoise
This application measures real-time sound pressure levels, displaying minimum and maximum values. It offers advanced analysis like third octave and FFT, with options to save data, calibrate, and share measurements with a community. Note: it is not intended for professional use.
- Real-time A-weighted sound pressure level measurement
- Minimum and maximum level tracking
- Third octave and FFT analysis
- Data saving in text file
- Calibration functionality
- Measurements displayed on a map
- Community sharing of calibration and measurements
Read full descriptionHide full description
OpeNoise is a real-time noise level meter. TECHNICAL SPECIFICATIONS: - Real-time A-weighted sound pressure level measurement - Minimum and maximum level - Third octave and FFT analysis - Data saving in text file - Calibration - Displaying measurements on a map - Metadata compilation - Sharing calibration and measurements with the OpeNoise community TERM OF USE This app is not intended for professional use, it does not necessarily guarantee an accurate noise measurement. Since each device has a different response to noise, a comparison with a professional noise level meter in the measurement dynamic range is required. The utilization of the app requires adequate technical knowledge and skill; an extemporary measurement might not be correct. The calibrations and measurements sent to the OpeNoise community will be used for statistical purposes only and cannot be used in any way to verify compliance with legal limits. CREDITS Developers: Arpa Piemonte (Regional Agency for the Protection of the Environment of Piedmont - Italy - www.arpa.piemonte.it). The code is open source under GNU v.2 license or later, the code is on GitHub: https://github.com/Arpapiemonte/ KEYWORDS noise level meter, level, sound, noise, measure, measurement, dB, db, dBA, dB(A), decibel
CJDecibel
This utility app offers real-time, high-precision decibel measurements to detect noise levels. It features a minimalist interface for easy operation, allows recording of detection locations, and enables sharing or exporting of historical data.
- Real-time decibel measurement
- High-precision detection
- Location recording
- Data sharing and export
- Detection history viewing
Read full descriptionHide full description
CJ Decibel - Noise Detection is an app that provides real-time volume decibel data detection, with the following features: - Real-time high-precision decibel measurement - Minimalist design, one-click detection - Recording of detection location information - One-click sharing and export of detection data - Easy viewing of detection history
Screenshots
Verdict
The clearest difference is rating: CJDecibel at 5.0 against OpeNoise's 4.0. CJDecibel also leads on update cadence (weekly vs every 7 months) and review sentiment (100% vs 86%). OpeNoise's advantage is ads (none vs shown) and monetization model (free vs ad-supported). On price, ratings volume, in-app purchases and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
CJDecibel holds the better App Store score, 5.0 against 4.0. Both are backed by a comparable volume of ratings — 4 and 2 respectively. Written reviews point the same way: 86% of OpeNoise's written reviews are positive against 100% of CJDecibel's.
OpeNoise ships an update every 7 months, CJDecibel weekly. The most recent releases landed on October 13, 2026 and October 3, 2026 respectively.
| Parameter | OpeNoise | CJDecibel |
|---|---|---|
| Price | Free | Free |
| Rating | 4.0 (4 ratings) | 5.0 (2 ratings) — better |
| Positive reviews | 85.7% of reviews | 100.0% of reviews — better |
| Number of ratings | 4 — better | 2 |
| Update frequency | Every 7 months | Weekly — better |
| Ads | No — better | Yes |
| In-app purchases | No | No |
| Monetization | Free — better | Ad-supported |
| Devices | iPhone, iPad, iPod — better | iPhone, iPod |
| Requires iOS | 15.0 | 11.0 — better |
| Further details — not scored | ||
| Size | 12 MB | 37 MB |
| Age rating | 4+ | 4+ |
| Developer | Arpa Piemonte | 炽金 练 |
Customer experience
OpeNoise
CJDecibel
In-app purchases
OpeNoise
No in-app purchases
CJDecibel
No in-app purchases
