Privacy policy

This is the part most people are asking about, so it goes first. When you grant microphone permission, the audio stream is processed entirely inside your browser to compute a sound level. It is never recorded to a file, never stored, and never transmitted to us or to anyone else. There is no upload step, and no server involved in producing a reading — the arithmetic runs on your device.

Closing the tab ends the measurement and discards the audio. You can revoke microphone permission at any time through your browser's site settings, and the meter will simply stop reading.

If you use the Pro session features, recorded sessions are saved in your browser's local storage under the key decibelpro.sessions.v1. Up to 25 recent sessions are kept, containing timestamps and decibel values — never audio. This data stays on your device and is not sent to us. Clearing your browser's site data deletes it, and doing so is the complete deletion process.

We use two analytics tools:

• Google Analytics 4, which sets cookies and records page views and interaction events — things like starting the meter, exporting a report, opening pricing, and following an outbound link. It collects a truncated IP address, approximate location derived from it, and browser/device characteristics. This is used to understand which pages are worth keeping and where the site is confusing.
• Ahrefs Web Analytics, which records page views without setting cookies.

Neither tool receives any audio, any decibel reading, or the contents of your measurement sessions. You can block both with any standard content blocker or a "do not track" browser setting, and the meter will work exactly as before.

Payments are handled by Stripe. Your card details are entered on Stripe's systems and are never seen by, transmitted through, or stored on ours. Stripe collects the information it needs to process a payment and to meet its own legal obligations, under its privacy policy.

We do not run a user database. There is no account record, no stored password, and no server-side profile of you. Access to Pro is proven by a signed token stored in a cookie named dp_license, which is set after a successful purchase. That cookie is httpOnly and SameSite=Lax, so it cannot be read by JavaScript on the page, and it contains your plan, an expiry, an issue time, a Stripe payment reference, and the email address you gave Stripe — which exists so the account page can show you which purchase you are signed in under.

Deleting that cookie removes Pro access from the device. Your purchase record continues to exist at Stripe, which is what makes it possible to restore access later.

Some pages link to products on Amazon through the Amazon Associates program, and we may earn a commission if you buy something after following one. Following such a link takes you to Amazon, which sets its own cookies under its own privacy policy. We record that an affiliate link was clicked as an analytics event; we do not receive information about what you subsequently bought.

• Audio, in any form, at any time.
• Your decibel readings or measurement history.
• Card numbers or payment credentials.
• Contacts, files, photos, or precise location.
• Any account credentials — there are none, because there are no accounts.

Because there is no user database, most data-subject requests resolve on your own device: clearing site data removes your sessions and your Pro cookie, and a content blocker stops analytics. For anything held by Stripe as a result of a purchase — or if you want to ask what a given purchase record contains — write to [email protected] and we will help.

The meter is used in classrooms, and nothing about a decibel reading identifies anyone. We do not knowingly collect personal information from children. No account is required to use the meter, and a student using it in a lesson provides us with nothing beyond the analytics described above.

If this policy changes materially, the "last updated" date above changes with it and the change is noted in the changelog. Questions about any of this go to [email protected].