Privacy policy

Last updated August 29, 2026

OpenSubs is a browser tool that transcribes speech into subtitles, translates them, styles them, and burns them into a video. This page describes exactly what data it collects, what it never collects, and why — matching what the source code actually does, since OpenSubs is open source and anyone can verify this directly.

What OpenSubs never collects

• Your video or audio. The file is read through an object URL and decoded by your browser. There is no upload endpoint in this product, so a footage leak is not something we have to promise against — it is not possible.
• What you subtitle. We have no record of which files you open, how long they are, or what is in them.
• Analytics of any kind. No tracking scripts, no cookies for measurement, no third-party fonts, no fingerprinting.
• Your API keys. If you bring your own key for a translation or transcription service, it is used from your browser directly to that provider. It is never sent to us and never written to disk.

What's stored locally, on your device only

• The speech model. The first time you transcribe, ONNX Whisper weights are downloaded from huggingface.co and cached by your browser. That is a download, not an upload — no audio is in the request.
• Your preferences. Chosen style, word effect, output size and similar settings live in your browser's local storage.
• Your session token, if you sign in. Used to check your credit balance and authorise paid translation.

Clearing your browser's site data for app.opensubs.app removes all of it.

Data that leaves your device, only if you choose it

• Subtitle text, for cloud translation. Selecting a cloud translator instead of the on-device one sends the subtitle lines to it. Never the video, never the audio — just the text. The on-device option sends nothing at all, and it is the default.
• Audio, for cloud transcription. Selecting an OpenAI-compatible transcription service and supplying your own key uploads the trimmed audio span to that service. Only the span you trimmed to, not the whole file.

Data used only if you sign in (optional)

You can use OpenSubs without an account. One is needed only to pay for translation on our own backend.

If you create one, we hold what an account needs: an identifier for how you signed in, your credit balance, and a ledger of what credits were spent on — the product and the feature, for example “OpenSubs · translate”. The ledger records that a translation happened and what it cost. It does not record the subtitle text.

Paid translation

When you translate on our backend, the subtitle lines are sent to gateway.opensubs.app, which passes them to the translation model we hold a key for and returns the result. The lines are used to produce your translation. They are not retained by us afterwards, and they are not used to train anything.

You are shown the price before the job runs and charged exactly that. A job that fails costs nothing.

Payments

Payments are processed by our payment providers. We never see or store your card details. Credit purchases and their reversals are recorded against your account so your balance is correct.

Third parties

• Hugging Face — hosts the speech model file. Contacted only to download it, once.
• A translation or transcription provider of your choosing — only if you select a cloud option, and under your own key unless you use ours.
• Our payment providers — only if you buy credits.

There are no other third parties. No CDN, no analytics vendor, no advertising network.

Data deletion

Local data: clear site data for app.opensubs.app in your browser.

Account data: email privacy@opensubs.app and we will delete your account and its ledger. Since the app itself holds nothing about you, that is the whole of what we have.

Children's privacy

OpenSubs is not directed at children under 13, and we do not knowingly collect information from them.

Changes to this policy

If this policy changes materially, the date at the top changes with it.

Contact

Questions about this policy: privacy@opensubs.app.