How to send a file that is too big for WhatsApp or email

Cut the file into numbered parts and send the parts. It is the only route that needs nothing from the person receiving it — no account, no app, no upload to a third party — and it works on any file of any size.

There are three other routes and they are each better in specific situations. Here is what every one of them actually costs you.

A 300 MB video becomes twelve 25 MB pieces, and twelve 25 MB attachments go through where one 300 MB attachment does not. The pieces are raw byte ranges named video.mp4.001, video.mp4.002 and so on.

The thing that makes this route good is that the recipient does not need your tool, or any tool. One command:

That is a claim worth testing rather than repeating, so we test it on every change: split a file with our tool, throw away everything the tool wrote except the numbered parts, reassemble them with cat, and compare digests against the original.

Nothing is added to the parts — no header, no index — which is what keeps that true. If a splitter writes its own marker into the pieces, you have quietly made the recipient dependent on that splitter.

The splitter here runs in the browser, so the file is never uploaded and its size is not a constraint. The limitation, since it decides whether the route is available to you: writing parts straight into a folder needs Chrome or Edge on a computer. Firefox and Safari cannot do that, so there each part arrives as a separate download with a click for each — workable for four parts, tedious for forty.

The mild annoyance of this route is that several small emails in quick succession can look to a mail provider like a pattern worth slowing down. Send them over a few minutes rather than all at once.

If the file is going from your phone to your own laptop, or to someone in the same room, turning it into an email attachment is a detour. A transfer session moves it once: a six-digit code on one device, the same code on the other.

Being direct about what this is, because the rest of this site argues that uploads are a cost: this one is an upload.The file goes to storage both devices can reach and is deleted when the session expires — 15 minutes of inactivity, 24 hours maximum. Our limits are 1 GB per file and 3 GB per session, which are real numbers rather than an “unlimited” that means something smaller.

Unlike splitting or hashing, this task cannot be done locally: something in the middle has to hold the bytes until the second device asks for them. That is the difference between a transfer and a tool, and it is why the tools on this site upload nothing and the transfer does.

Cloud storage is the default answer and it is the right one more often than this site’s usual argument suggests. If the file is not sensitive and the recipient is happy to click through a consent screen, a link is the least friction available.

What you are paying is a copy. The file now sits on a third party’s disk, under their retention policy, attached to your account, for considerably longer than the link stays useful. That is a fine trade for holiday photos and a poor one for a contract, a scan of a passport, or a database dump.

Physical media has no size limit worth worrying about. The filesystem does, and this is the one that catches people: a stick formatted as FAT32 cannot hold a single file larger than 4 GB, no matter how empty it is.

The failure is baffling in the moment — 200 GB free, and the copy just refuses. Most sticks ship as FAT32 because it is the format every device reads, so this is common rather than exotic. Splitting fixes it, and our part-size presets include a 2 GB option sized under the ceiling for exactly this.

Both devices are mine and to hand:send it directly. There is no reason for a copy to exist on a stranger’s disk for a file that is going three feet.

Ordinary file, recipient elsewhere: a cloud link. The copy does not matter and it is the least work for both of you.

Sensitive, or crossing a filesystem limit, or the recipient cannot install anything: split it. It is the only route on this list where the file never reaches a server at any point, and the only one where the person at the other end needs nothing they do not already have.

One thing I would not bother with: the “just zip it” suggestion that appears in most answers to this question. Video, photos and PDFs are already compressed, so there is nothing left for ZIP to find. Measured on a video and a log file of comparable pointlessness and usefulness:

Zipping media buys you nothing and costs the recipient a step. Zipping text, spreadsheets or a folder of many small files is transformative. Know which one you are holding.