How to send large files through Gmail

By Hein de Wilde··4 min read

Gmail caps attachments at 25 MB, and because attachments are encoded about a third larger than the file on disk, the practical ceiling is nearer 20 MB. Attach something bigger and Gmail offers to put it in Google Drive and send a link instead — which works, but changes what you are actually sending in a way worth understanding before you use it for client work.

What Gmail does when the file is too big

Drag in a file over the limit and Gmail uploads it to your Drive, then inserts a link. The email sends fine. The recipient clicks and lands on Drive.

The important difference: you have not sent them a copy. You have granted them access to a file in your storage. Three consequences follow.

Your Drive is now the delivery surface. If you later move, rename or reorganise that file, you have changed what their link does. Tidy your Drive in a year and their link breaks.

Sharing scope is easy to get wrong. Gmail will prompt you to grant access if the file is not already shared. If you have previously set a whole folder to "anyone with the link", a file added to it inherits that — which is the most common accidental over-share in this category.

They may need to sign in. Depending on your organisation's Workspace settings, external recipients can hit a sign-in wall or a request-access screen. Sending a paying client into that is a poor experience, and you will not see it yourself because you are already signed in.

Size limits worth knowing

  • Gmail attachment cap: 25 MB, roughly 20 MB of real file after encoding.
  • The recipient's server also has a limit, which you cannot see. Corporate mail servers are often 10 MB. A 20 MB attachment can be accepted by Gmail and bounced by theirs.
  • Google Drive takes files up to 5 TB for non-Google formats, per Google's own documentation checked 1 August 2026. Documents converted to Google Docs format are limited to 1.02 million characters, or 50 MB when converting; presentations converted to Slides are limited to 100 MB.

So Drive is not the constraint. The question is only whether a Drive link is the right way to hand something over.

When the Drive link is fine

  • The recipient is a colleague inside the same Workspace.
  • You want them to see updates as you make them.
  • It is a working document rather than a finished deliverable.
  • You do not mind managing that permission indefinitely.

When to send a transfer link instead

  • The recipient is outside your organisation.
  • The file is finished — a delivery, not a draft.
  • You want it to expire, or to be able to revoke it.
  • You do not want them to need an account.
  • You would rather not have your storage be the thing they are reaching into.

For a client deliverable, that is nearly always the better shape. You upload, they download a copy, the handover ends. Nothing stays connected to your filesystem.

The relevant contrast with Drive is not size — Drive will take a 5 TB file, per Google's own documentation checked 1 August 2026, which is more than any transfer service here. It is that a transfer service hands over a copy that expires, and Drive lends out a key that does not. Free ceilings across the transfer services run from 2 GB to SwissTransfer's 50 GB; the comparison has each one and the date it was checked.

Practical steps

Under 20 MB: attach it normally, unless you know the recipient's mail server is stricter.

Over 20 MB, internal: let Gmail use Drive. Check the sharing scope it proposes — read it rather than clicking through, because that prompt is where over-sharing happens.

Over 20 MB, external or finished work: upload to a transfer service and paste the link. Say what the file is, roughly how big, and when the link expires. A bare URL with "here you go" reads like phishing and increasingly gets filtered like it.

Anything with personal data in it: use a link with an expiry, and if you add a password, send it by a different channel — never in the same email. How to send confidential documents covers the rest.

One thing to check in your Drive today

Open Drive, and look at anything shared as "anyone with the link". Most people have folders in that state from years ago, and every file dropped into them since has inherited it.

That is not a Gmail problem exactly, but Gmail's attachment handoff is how most of those folders got that way — one prompt at a time, clicked through while sending something else. It takes five minutes to review and it is the highest-value thing on this page.

If you want the fuller argument about handing over a copy versus lending a key, it is here.

Hein de Wilde

I build and run Yungle, and I write everything here. Comparisons name competitors and credit them, every claim about another company comes from that company’s own documentation, and where we fall short it says so. More about who is behind this.

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