Loudness Check privacy policy

Last updated: October 4, 2026

Loudness Check is an app for ChatGPT, published by Haiden McGill ("we", "us"). It measures the loudness of an audio file and can export a gain-adjusted copy. This policy explains what happens to your data when you use it.

Your audio

Loudness Check processes audio in your browser, inside the app window in ChatGPT. Decoding, measuring and normalizing all happen on your device. Your audio is never sent to our servers.

There are two cases where audio is stored by OpenAI, the operator of ChatGPT, rather than staying only on your device:

• Files you attach to a ChatGPT message. If you attach an audio file to your message instead of choosing it inside the app, ChatGPT stores that file. The app then loads it from ChatGPT into your browser to measure it. Our servers receive only a link to the file, which they do not open, store or log.
• Downloading a normalized file in ChatGPT. ChatGPT does not let apps save files directly to your device. To give you a download link, the app uploads the normalized file to ChatGPT's file storage. The app tells you this before you download.

In both cases OpenAI's privacy policy applies to those files: https://openai.com/policies/privacy-policy/

What we share with ChatGPT

After measuring, the app sends ChatGPT the file name and the measurement results (loudness, true peak, loudness range, sample rate, channel count, duration and the chosen target), so ChatGPT can talk about them with you. It never sends the audio itself or a waveform.

What our servers receive and log

Our server tells ChatGPT which loudness targets exist and provides the app's interface. When ChatGPT contacts it, the server receives the target you asked about and, if you attached a file, a link to that file.

For each request we log only technical metadata: the time, the type of request, the tool name, the size of the request, the response status and how long it took. We do not log the content of requests, file links, file names or measurement results. Our hosting provider, Vercel, processes IP addresses to deliver the service; see https://vercel.com/legal/privacy-policy. We keep these request logs for no more than 30 days.

Website

The pages at heyhaiden.com/loudness-check use PostHog to count page views in aggregate. It runs in cookieless mode: it sets no cookies, stores nothing on your device and does not identify you. PostHog receives the page address, the referring site and basic browser and device information, and uses your IP address to count unique daily visitors without storing it; see https://posthog.com/privacy. The app itself contains no analytics.

What we don't do

We don't require an account, use cookies in the app, sell personal information, or use your audio or results to train models.

Children

Loudness Check is not directed at children under 13, and we do not knowingly collect their personal information.

Changes

We will update this page if our practices change and revise the date above.

Contact

Questions about this policy: support@heyhaiden.com