Caption your video without uploading it
Almost every caption tool requires you to upload your footage to their servers first. AI Caption Cut does not — the speech-to-text, styling and rendering all happen in your browser, on your own device. Your video never leaves your machine.
Or open the full editor to style the captions and burn them into the video.
Why on-device matters
Uploading your raw footage means trusting a company to store, process and delete it. For client work under NDA, unreleased content, anything personal, or footage you simply would rather not hand over, that is a real problem — not a hypothetical one.
Because AI Caption Cut reads the file from your disk and processes it locally, there is nothing to upload and nothing stored elsewhere. It also removes the upload wait and the file-size limits that cloud tools impose.
How it works without a server
The speech model runs in your browser using your device’s own processor. Captions are generated with word-level timing, styled on a live preview, and the final video is rendered locally and saved back to your disk.
The honest trade-off: your laptop is not a GPU farm, so a long video takes real minutes to transcribe. In exchange you get privacy, no upload wait, no size cap, no account, and it keeps working offline.
Check it yourself, in about a minute
This is a claim, and a claim about privacy is worth exactly what it can be verified to be worth. Two ways to check it, neither of which requires taking our word for anything.
Open your browser’s developer tools before you start, switch to the Network tab, and caption a video. You will see the speech model download once from huggingface.co, and you will not see your video go anywhere — there is no upload request to find, because there is no endpoint that would receive one.
Or do the blunter version: load the page, turn off your Wi-Fi, and caption the video anyway. It works. A tool that was sending your footage to a server could not.
What leaves your device, precisely
Being exact about this is more useful than saying "nothing", because "nothing" is never quite true of any web page and a reader who finds the exception stops believing the rest.
Your video, your audio and your captions never leave your device. The speech-to-text model is downloaded to you once and cached, so the traffic runs in that direction rather than the other. A small anonymous record of which step a session reached — opened the editor, generated captions, exported — is sent so we can see where the product breaks; it carries no video, no filename and no caption text, and it is gone when the tab closes. If you pay, the payment goes to Razorpay like any other checkout. That is the complete list.
Who needs this rather than a cloud tool
Editors and agencies working under NDA, where uploading a client’s unreleased footage to a third party is a contract question rather than a preference. Journalists and documentary teams with material that identifies a source. Lawyers, clinicians and HR with recordings that are confidential by law or by duty. Teachers and universities with video of students in it. Anyone with a cut that is not announced yet.
In every one of those cases the blocker is not the price of a caption tool, it is that the footage cannot be handed to anyone. On-device processing is not a nicer version of a cloud tool for these people — it is the difference between being able to use one at all and not.
What uploading actually commits you to
Upload-based tools are not being sinister; they are being ordinary. Your file lands on their servers, is copied to whatever storage and transcription services they build on, and sits in each of those places for whatever retention window they operate. Their terms usually reserve the right to process it, sometimes to improve their models, and those terms can change after your footage is already there.
None of that is unreasonable for a public marketing clip. It is a different conversation for footage you do not own outright, and it is a conversation that cannot happen at all if the file never moves.
Free, private, no subscription
AI Caption Cut is free to use, with unlimited exports at 480p carrying a small watermark. Removing the watermark is a one-off payment for that one video — 720p, or full 1080p at 60fps — or an Unlimited Pass that covers every export for thirty days. Subtitle files are free either way. It is charged in your own currency at checkout, and there is no subscription and no account.
Questions
Can I add captions to a video without uploading it anywhere?
Yes. AI Caption Cut runs entirely in your browser on your own device. Your video is read from disk, captioned and rendered locally, and never uploaded to any server.
Is it safe for confidential or client footage?
Because nothing is uploaded, your footage never leaves your device — there is no server copy to store, leak or subpoena. That makes it suited to NDA work, unreleased content and anything personal.
How can it caption without a server?
The speech-to-text model runs locally in your browser using your device’s processor. There is no cloud step, which is also why there is no upload wait and no file-size limit.
How do I verify my video is not being uploaded?
Two ways. Open your browser’s developer tools, switch to the Network tab and caption a video — you will see the speech model download once, and no request carrying your file. Or load the page, turn your Wi-Fi off, and caption the video offline, which a tool that needed a server could not do.
Does it work offline?
Yes, once the page and the speech model have loaded. The model downloads the first time you generate captions and is then cached, so later videos can be captioned and exported with no connection at all — on a plane, or on a machine that is deliberately kept off the network.
Do you store my video, and can you hand it to anyone?
We never receive it, so there is nothing to store and nothing that could be handed over, subpoenaed or leaked. The file is read from your disk by your own browser and the finished video is written back to your disk.
Can I use it for client work under NDA?
That is the case it is built for: the footage never leaves your machine, so captioning it involves no third party at all. We make no compliance certification of any kind — what we can tell you is exactly what happens to the file, which is nothing, and you can verify that in the Network tab before you rely on it.
Is there a file-size or length limit?
No. Cloud tools cap file size and duration because every minute costs them upload bandwidth and compute. Rendering happens on your own device here, so it costs us nothing per minute and there is no reason to cap it. A long video simply takes longer on your hardware.
Is it free?
AI Caption Cut is free to use, with unlimited exports at 480p carrying a small watermark. Removing the watermark is a one-off payment for that one video — 720p, or full 1080p at 60fps — or an Unlimited Pass that covers every export for thirty days. Subtitle files are free either way. It is charged in your own currency at checkout, and there is no subscription and no account.
Related free tools
Try it on your own video
Nothing to install, no account, and your video never leaves your device. Unlimited free exports, and a one-off payment when you want the watermark gone.
Caption my video — free