A private video editor that never uploads your file
Cut, speed up and slow down video without a copy of it ever reaching a server. The editing runs inside this browser tab, there is no account, nothing is watermarked — and you can check every claim on this page yourself in about ninety seconds.
Drop your video here
or click to browse — MP4, MKV, MOV, WebM, AVI and more
What "no upload" actually means here
Nearly every free online video editor is a web form in front of a rendering farm. You choose a file, it is transferred to storage the operator controls, a server decodes and re-encodes it, and you download the result. That architecture is why those tools ask you to sign in, why they cap file size, why the free tier watermarks the output, and why the upload is the slowest part of using them.
This editor has no such step. FFmpeg — the library almost all video software is built on — has been compiled to WebAssembly and runs inside the page. Your video is read off your own disk into the tab's memory, decoded, filtered and re-encoded there, and handed back as a download. There is no upload endpoint in the application, so there is nothing for a file to be uploaded to.
The consequences follow from the architecture rather than from a policy document: there is no size cap because there is no bandwidth bill; there is no account because there is nothing to associate with one; there is no retention period because nothing is retained; and the tool keeps working with the network switched off.
Everything this site sends and receives
A privacy claim is only worth something if it is specific. This is the complete network inventory for a page on this site — not a summary of it.
The page itself
HTML, CSS and JavaScript from alter.video. No third-party fonts, no CSS frameworks fetched from a CDN, no images beyond the inline SVG icons.
The FFmpeg engine
About 32 MB of WebAssembly, fetched from alter.video the first time you apply an edit and cached by your browser afterwards. This is program code arriving; it carries nothing away.
One analytics page view
A cookie-less request to api.panalytics.money per page view, recording the page address, the referrer, any campaign parameters in the URL and how long the page stayed open. It runs on the page, not in the editor, and has no visibility into your file.
Your video
There is no upload endpoint in this application. The file is read from disk with the browser File API, written into FFmpeg's in-memory filesystem, processed there, and read back out as a Blob for the download link.
The privacy page states the same facts in the same terms. If the two ever disagree, the privacy page is the one that is wrong and it is a bug.
How to verify it yourself, in ninety seconds
- 01
Open the Network tab
Press F12, or right-click and choose Inspect, then switch to Network. Tick "Preserve log" so nothing is cleared as you work.
- 02
Load a video and apply an edit
Use a file large enough to be unmistakable — a hundred megabytes or more. Watch the request list as the edit runs.
- 03
Look for an outbound request the size of your file
Sort by size and read the request payloads, not the response sizes. A 200 MB upload cannot hide: the bytes have to cross the wire and the wire is instrumented. You will find the ~32 MB engine coming down and nothing of comparable size going up.
- 04
Then do the offline test
With the engine cached, set the Network throttling dropdown to Offline — or just turn off Wi-Fi — and edit another video. It still works. Processing that continues with no network cannot be happening on a server.
The offline test is the one that settles it, because it rules the possibility
out rather than merely failing to observe it once.
The long version of this method
covers reading request payloads properly, spotting sendBeacon
calls, and checking WebSockets — and it applies to any tool you are evaluating,
not just this one.
When it actually matters
Most of the time nobody cares where a cat video gets trimmed. These are the cases where people specifically go looking for a tool that does not upload.
Recordings of other people
A meeting, an interview, a consultation, a class. Consent to be recorded is not consent to be uploaded to a third party, and you are the one who would have to explain the difference.
Work under an NDA or a policy
Screen recordings of internal tools, unreleased products, customer data on screen. Many organisations prohibit uploading company material to third-party services outright, and a browser tool sidesteps the question entirely.
Regulated or sensitive material
Anything touching health, legal or financial information, where a copy on someone else's infrastructure creates an obligation you did not intend to take on.
Personal footage
Family video, medical footage, anything from inside your home. There is no reason for it to exist on a server, and no way to un-upload it once it does.
Restricted or slow networks
On a school, hospital or corporate network, uploading a gigabyte may be blocked, throttled or simply slower than the edit itself. Local processing is unaffected by any of it.
Large files
A cap is a business decision on a server-based tool, and there is no server here to impose one. The real ceiling is your device's memory, which is a different constraint with different workarounds.
The honest limits of this guarantee
Client-side processing is a narrow, specific guarantee, and it is worth being precise about its edges rather than letting "private" do unearned work.
It is not encryption. Your file sits on your disk in the clear, exactly as it did before. Anything with access to your machine still has access to it.
You are trusting the code you ran today. Verifying the network traffic proves what this version did in that session. It is not a promise about every future version. That is true of all software; the difference is that here you can re-check in ten seconds whenever you like.
Your device is the ceiling. The encoding runs on your CPU and the file lives in your RAM, so a long 4K clip takes longer here than it would on a rented server, and a very large one may not complete at all. What the real ceiling is, and how to work within it.
There is still one third-party request. The analytics script is a page-view counter, and it is disclosed above rather than buried. If you block it, everything on the site continues to work.
Questions about private, no-upload video editing
Is this video editor really private, or is that just marketing?
Does the site track me at all?
Do I need an account, an email address or a sign-in?
Is there a watermark on the output?
Can I use it with no internet connection?
What does it not protect me from?
Why can Canva, VEED and Clideo not offer this?
Where to go next
The three operations each have their own page: cut a section out, speed a section up and slow a section down. If you want the mechanism rather than the guarantee, how browser video editing works walks through every stage, and the formats page covers what you can open and export.