Privacy and data handling

Open Audio Analyzer collects nothing. There is no account, no sign-in, no analytics, no telemetry, no crash reporting, no advertising and no third-party service of any kind. The application makes no connection to the internet at all — not to check for updates, not to fetch anything, not to report that it ran. Every measurement it takes is computed on your machine and discarded when the next one replaces it.

This page is the whole of it, written out rather than summarised, because a metering tool asks for a microphone and a camera and a local network and the honest thing to do is say what it does with each. It is also the privacy policy for the iPadOS listing on the App Store, for the desktop builds on macOS, Windows and Linux, for the oaa command-line analyser, for the VST3 and Audio Unit plugin, and for this website.

Everything below is checkable. The application is free software and the whole of it is public — the network code is in lib/src/remote/, the protocol it speaks is specified in the wire protocol, and the only code in the application that touches the filesystem is one file, config_store.dart. A claim on this page that the source contradicts is a bug; please report it.

Last updated 23 August 2026, for version 0.10.1.

The short version

The microphone, and the audio it measures

The application measures a signal — that is what it is for. On iPadOS it asks for the microphone permission; on the desktop it opens the input device you choose. The Android build never asks, because it is a remote display only and does not meter anything itself: it declares no RECORD_AUDIO permission at all, so the question cannot arise.

Audio is measured and discarded. Samples are pushed into the measurement engine, which reduces them to numbers — loudness, peak level, a spectrum, a correlation coefficient — and the buffer is reused for the next block. Nothing is written to disk, nothing is kept in memory beyond the moment, and nothing is transmitted anywhere by this. There is no recording feature, and adding one would be a change to this page as much as to the application.

The permission is asked for once, when you first start metering, and iPadOS lets you withdraw it at any time in Settings. Withdrawing it stops the live meters; nothing else in the application depends on it.

The camera

On iPadOS, Android and macOS the host picker offers Scan a QR code, which reads a pairing code shown on the screen of the machine you want to watch. That is the only thing the camera is used for.

Frames from the camera are examined for a QR symbol and then dropped. Nothing is recorded, stored, uploaded or kept, and no image is ever written to disk. The code being scanned carries one thing — an address of the form oaa://host:port — and nothing else.

The scanner uses mobile_scanner, the one dependency in this project with a native component that is not vendored here. It runs entirely in-process and makes no network connection. It is absent on Windows and Linux, which is why the row is not shown there.

The local network

The remote display feature draws one machine’s meters on another screen — a desktop publishing to an iPad, or a DAW plugin publishing to the desktop application. This is the only networking in the product, and all of it stays on your own network.

Nothing is published until you turn it on. The desktop application does not listen on any port until you switch on PUBLISH; a plugin instance connects only to the machine it is running on. There is no default that shares anything.

When publishing is on:

• The application advertises a service of type _oaa._tcp over multicast DNS on the local network, so that a tablet can find it without anybody typing an address. The advertisement carries a name, which defaults to your computer’s hostname and is editable in the publish settings — set it to whatever you like. It is visible to anything else on the same network that is browsing for services, which is how service discovery works everywhere.
• Port 47821 carries measurements and the canvas layout from the application to a connected display. Port 47822 carries measurements from a plugin instance to the application on the same machine.
• What travels is numbers and the description of a layout: loudness values, peak levels, spectrum bins, the transport position the DAW reported, the names of your tabs and modules, the colours of the skin you are using and the delivery target you have selected. Audio never travels. There is no frame in the protocol that can carry it, which is a property of the format rather than a promise about the code — see the wire protocol.
• Nothing leaves your network. Both ends are on the same LAN by construction: the address is discovered by multicast, which does not cross a router, or typed in by you.

On iPadOS the local network permission is requested the first time you look for a host, and can be withdrawn in Settings. Withdrawing it stops discovery and nothing else.

One thing that looks worse in a permission list than it is: the Android build declares android.permission.INTERNET. Android requires that permission to open any socket, including one to a machine in the same room, and it is the only way to reach a host on your own network. It is not used to reach anything beyond it. The Android build also declares CHANGE_WIFI_MULTICAST_STATE, which is what lets it receive the mDNS answers it would otherwise have filtered out, and deliberately does not declare NEARBY_WIFI_DEVICES — scanning and managing Wi-Fi networks is something this application never does.

The link is not encrypted, and it is not authenticated

Stated plainly because it is the one thing on this page that is a limitation rather than a reassurance: the display link has no encryption and no authentication. Anyone who can reach port 47821 on your machine while publishing is on can read the measurements and the layout.

That is a deliberate trade for a feature that is LAN-only, and it is why the host does not listen at all unless a person switches it on. It is also why the link is one-directional: a connected display can draw the meters and can change nothing — the protocol has no frame that lets it, and the port rejects one if it arrives. The reasoning is written out in full under They do not have the same trust boundary.

What follows from that, practically: publish on a network you trust. On a shared or public network — a venue, a hotel, a rehearsal room with an open access point — leave PUBLISH off, or expect that anybody on it who is looking can see what your meters read.

Files you analyse

Opening a file for offline analysis reads it from your disk, measures it, and shows you the report. The file is not copied, not modified and not uploaded. Exporting a report writes it where you choose and nowhere else.

What is stored on your device

Your configuration, and nothing else. It is plain JSON you can read, and it contains only what you set up:

• Settings, the canvas layout, your tabs and modules
• Presets, delivery targets, skins and any meter calibrations you save
• The name and port used for publishing, and the address of a host you last connected to

No measurement is ever written to it. No identifier is generated, stored, or derived from your hardware — there is no installation id, no device fingerprint, and nothing that could distinguish one copy of this application from another.

Where it lives:

Deleting the application removes it on iPadOS and Android. On the desktop, delete the directory above. There is nothing anywhere else to delete, and nothing held by anybody else that could be deleted on request — see Your rights for why that section is short.

Children

The application is rated 4+ and is suitable for all ages. It collects nothing from anyone, so it collects nothing from children either. There is no user content, no messaging, no social feature and no link out of the application to anything that is not this project’s own documentation or source code.

Apple’s App Privacy answers

The listing declares Data Not Collected in every category, which is accurate: no data of any kind is transmitted off the device by the application. For completeness, against Apple’s own list —

The application uses no third-party SDK, so there is no partner disclosure to make. ITSAppUsesNonExemptEncryption is declared false in the bundle: the application contains no encryption.

This website

open-audio-analyzer.com is a static site with no analytics, no tracking pixels, no advertising and no cookies. Nothing is stored in your browser and nothing about your visit is recorded by this project.

Three things are worth naming anyway, because a site that claims to send nothing anywhere should account for every request a browser makes:

• Hosting. The site is served by Cloudflare, which as a hosting provider processes the request — including your IP address — in order to deliver the page, and keeps operational logs of it for a short period. This project has no analytics product enabled on that account and reads no per-visitor data from it. Cloudflare’s own handling is described in their privacy policy.
• Fonts. The page loads three typefaces from Google Fonts (fonts.googleapis.com and fonts.gstatic.com), which means your browser makes a request to Google and Google therefore sees your IP address. No cookie is set by it and nothing identifies you to this project, but it is a third-party request and it is disclosed here rather than left to be found in a network inspector.
• The live demo. Pressing the button on the front page that starts the running analyzer loads a graphics renderer from www.gstatic.com, which is the same kind of request. It happens only when you press it; a reader who does not press it makes no such request.

Nothing on this site asks for personal data. There is no form, no comment field, no newsletter and no login.

Your rights

Under the GDPR you have the right to know what personal data is held about you, to have it corrected or erased, to object to its processing, and to have it handed to you in a portable form.

This project holds no personal data about you, so in practice there is nothing to disclose, correct, erase or export. The rights are stated here because you have them, not because there is a database behind them. If you believe otherwise, ask — see below — and if the answer does not satisfy you, you may complain to a supervisory authority in the country you live in.

Contact

Questions about this page, or about anything in the application that appears to contradict it, go to the issue tracker:

https://github.com/JonasGrunau/open_audio_analyzer/issues

It is public, which is the point: a question about what a program does with a microphone is worth answering where the next person can read the answer. An issue is also the fastest way to get a correction made, since the page and the code it describes are in the same repository.

Changes to this page

This page is versioned with the application and lives in the repository as docs/site/privacy.md. Every revision is in the commit history with its date and its reason, so what this page said on any given day is a matter of record rather than of trust.

A change that affects what the software does with your data will be noted in the changelog in the same release, and the date at the top of this page will move.