Do online converters keep your files? A side-by-side comparison

Yes. Every converter that works by uploading keeps your file for a period, because the download link you click afterwards has to point at something. As of 22 August 2026 the published windows range from "instantly after conversion" for the file you sent up to seven days for the file you get back.

The number is only half the answer. Where the copy sits, what is recorded next to it, and whether the service reserves any right to look at it all differ from vendor to vendor. The table below quotes each policy directly, and the last section covers the one architecture where the retention window is genuinely zero: converting the video inside your own browser tab, so it never leaves the machine.

What each service says, in its own words

These are quotations from the vendors' own privacy policies, read on 22 August 2026. Policies change, so treat this as a snapshot and check the source before relying on it.

Two details there matter more than the headline hours. Convertio separates the file you uploaded from the file it produced and deletes the first straight away — a real design choice, not marketing. And where a policy puts a number on both, the log retention window is the longer of the two. The video is gone; the record that you converted a video from your IP address at a given time is not.

Why the window cannot be zero on a server

People read "deleted immediately" and picture a service that never stores the file. That is not what happens, and no honest policy claims it. A server-side conversion has a fixed shape:

1. Your browser uploads the video over HTTPS. It is now written to disk — or to object storage — on a machine you do not control.
2. A worker picks the job off a queue, often on a different machine, so the file may be copied again.
3. The encoder writes a new file. Two copies now exist.
4. A download URL is issued and handed back to you.
5. Both copies are deleted when the timer expires or you dismiss them.

Step four is why the window is non-zero. The service cannot delete the output the instant it is made, because you have not downloaded it yet — you may still be on the upload page, or you may have closed the laptop. The window is a compromise between your convenience and their storage bill, and anything from eight to 24 hours is a sensible answer to that problem.

The same shape explains the file-size ceilings and queue waits: the video has to travel twice, over your upload connection, which is the slow direction. That is why the thresholds in our guide to video files that are too large to email tend to bite in the same places.

The questions that matter more than the hours

What is stored next to the file

Deleting the video does not delete the row in the database. IP address, timestamp, formats, duration and file size are cheap to keep and useful for abuse prevention, so they are — for 30 days at Zamzar, 180 at CloudConvert, and indefinitely in a policy that just says the journal is "kept for a long time". None of that is the content of your video. All of it is a record that the conversion happened.

Who may open the file

Most policies say plainly that processing is done by machine with no human interaction. Several also carve out an exception. FreeConvert's is typical:

"We will only access or view your files with your explicit and written consent unless such action is necessary to comply with legal procedures."

That is a reasonable clause — a company promising it would never comply with a lawful order would be lying. But it is the clause that answers the question you were actually asking: access is technically possible, and the policy defines when it is permitted.

Which country the disk is in

Location decides which authority can compel disclosure. The five above split between Germany, the wider EU, Ireland and the United States, and one explicitly warns of transfers abroad. If your footage is covered by an employment contract, a client NDA or sector rules, that line matters more than eight hours versus 24.

Whether an account changes the deal

Retention windows quoted for anonymous use often do not apply once you sign in, because a file history is a feature people want. Zamzar's policy, for example, ties deletion of account files to account deactivation rather than to a short timer. Read the account paragraph, not just the headline one.

How to read a converter's policy in two minutes

Open the privacy policy — not the marketing page, which will say "secure" and stop there — and use Ctrl+F for the word "delete". Then answer six questions:

• Is a specific number of hours or days given, or only a vague "as soon as possible"?
• Are the uploaded file and the converted output covered separately?
• What is the log retention period, stated in a different sentence?
• Which country or provider holds the storage?
• Is there a consent or legal-process exception to the no-human-access promise?
• Do the same rules apply if you create an account?

A policy that answers all six in plain numbers is a good sign, whatever those numbers are. A page offering adjectives instead of hours is the one to watch. Our broader look at whether online video converters are safe covers the rest of the checklist, including ads, redirects and bundled downloads.

When any of this is worth caring about

For a clip off YouTube, honestly, it is not. An eight-hour window on a meme is a non-issue, and pretending otherwise would be scaremongering.

It matters when the video is unreleased client work under NDA, something filmed inside a workplace, lab or hospital, footage of children, a screen recording showing account details or a customer's data, a legal or insurance recording, or anything you are contractually forbidden to hand to a third-party processor. Then the question is not "do they delete it?" but "did a copy leave my machine at all?" — which is what your employer's policy or your client's contract is written around.

The only window that is actually zero

If the file is never uploaded, there is no retention policy to read. That is how the converter on this site works: FFmpeg compiled to WebAssembly runs in a Web Worker inside your tab, reads the file you picked, and writes the result to your Downloads folder. No server sees it. The encoder downloads on your first conversion, not when the page opens; after that you can switch the network off and conversions still complete — a test you can run yourself, and the only privacy proof that requires trusting nobody.

Being honest about the trade-off, because it is a real one:

• Files over 2 GB are refused. A 32-bit WebAssembly heap cannot address them.
• Above roughly 300 MB you are warned, because the conversion needs about three times the file size in free memory.
• The build is single-threaded, so a genuine re-encode is slow — roughly real-time for 720p, slower than that for 1080p, and several times worse for H.265 or VP9.

The saving grace is that many everyday conversions are not re-encodes at all. When the codec inside your file is already legal in the container you want — H.264 moving from a MOV or an MKV into an MP4 — the tool copies the streams across instead of re-compressing them. That is near-instant however long the clip is, and the picture is bit-for-bit identical. Our guide to converting MKV to MP4 without losing quality explains when that applies and how to tell before you press Convert.

For files over 2 GB, or hours of 4K, the iPhone app and the Android app use the phone's hardware encoder and have no size ceiling — on iPhone the first conversion is free and further ones need the paid upgrade, while the Android app is free and unlimited. If you would rather install desktop software, our HandBrake alternatives guide covers that route, and the CloudConvert alternatives guide takes the vendor-by-vendor comparison further. None of them upload anything, which is the point: "how long do they keep my file?" only has an answer once somebody else has the file.