Gmail Attachment Size Limit: How to Send Large Files in 2026

Gmail’s 25 MB attachment cap has not moved since 2007, even as the average phone now shoots 4K video that crosses 25 MB in under a minute. Google’s own help page on attachment limits (updated 2024) confirms the rule has not changed, and Google Workspace’s 2025 admin documentation still ranks email-size limits among the most-asked questions from new admins. Outbound attachments cap at 25 MB per message; receiving caps at roughly 50 MB; anything larger auto-routes through Google Drive as a sharable link, where files can reach 5 TB. Here is the exact mechanic, why the cap exists, and the fastest workarounds when 25 MB is not enough.

The 25 MB / 50 MB rule in one sentence

Gmail allows you to send messages up to 25 MB total per email and to receive messages up to roughly 50 MB. Files larger than 25 MB on send are automatically uploaded to Google Drive and inserted as a sharable link, where the per-file cap is 5 TB. The 25 MB outbound limit applies to the entire message — body text, headers, every attachment, plus MIME encoding overhead — not to a single attachment in isolation.

The numbers most users want are simple: send 25 MB max, receive 50 MB max, Drive overflow up to 5 TB. Everything below is detail around those three caps.

A practical way to remember it: if you are the sender, plan around 25 MB. If you are the recipient, plan around 50 MB — your inbox accepts messages other senders relay through gateways that may have repacked the MIME envelope. The asymmetry exists because Gmail wants to receive everything legitimate that other mail systems can produce, but it does not want to be the source of bloated outbound mail.

I tested sending a 27 MB ZIP from Gmail web in May 2026: the compose window detected the size before send, removed the attachment, uploaded it to my Drive in the background, and inserted a “Shared via Google Drive” link card in place of the file. The email itself sent under 1 MB. That is the design — Gmail never tries and fails to send a 27 MB attachment; it pre-empts the failure by routing the file through Drive.

For storage maths around what Gmail and Drive count toward your 15 GB free quota, see the Gmail storage full guide — every file you push through Drive counts toward your shared Google quota.

Why Gmail enforces 25 MB (and why MIME bloat matters)

Two reasons: SMTP-era infrastructure protections (relays, anti-virus, anti-abuse scanners) all assume sub-25 MB messages, and MIME Base64 encoding inflates raw bytes by about 33 percent — meaning a 24 MB file on disk becomes roughly 32 MB on the wire. Gmail measures the encoded size against the 25 MB ceiling, which is why files that “look” small still trip the limit.

The 25 MB number is not arbitrary. SMTP, the protocol Gmail speaks to other mail servers, was never designed for large file transfer — it was designed for short text messages. Bodies and attachments must be encoded as 7-bit ASCII, which forces binary content (any image, ZIP, video, PDF) through Base64 encoding. Base64 expands bytes by a fixed ratio of about 4:3, so a 24 MB raw file becomes roughly 32 MB once encoded for transport.

Gmail’s 25 MB is the size of the encoded message, not the raw file. That is why the practical raw-file ceiling for “this will fit in Gmail without Drive” is roughly 18 MB — beyond that, encoding overhead pushes you past the cap.

The cap also serves three operational purposes:

Receiver-side anti-abuse. Every inbound message gets scanned for malware, spam signals, and policy violations. Larger messages cost more CPU per scan; capping at 25 MB outbound means receiving servers see predictable workloads.
Storage discipline at scale. Gmail handles billions of messages a day. Capping per-message size keeps storage and replication costs bounded.
Encouraging Drive usage. Files in Drive can be revoked, audited, and version-controlled. Files attached to email cannot be unsent or revoked once delivered. Routing large files through Drive is better hygiene for sensitive content.

The result: 25 MB is a stable design point, not a bug. Google has not raised it in nearly two decades, and the 2024 attachment documentation still lists the same number. Plan around it.

Sending large files via Google Drive — the official path

Click the Google Drive icon (the triangle) in the Gmail compose toolbar, pick or upload the file, and Gmail inserts a sharable link directly in the message body. Before sending, the dialog asks who can access the link — Anyone with the link, Restricted to recipients, or already-shared. Drive’s per-file cap is 5 TB, so this path covers virtually any practical file.

The mechanics in Gmail web:

Compose a new message. Add the recipient and subject as usual.
Click the Insert files using Drive icon in the compose toolbar (the triangular Drive logo, not the paperclip).
Either pick a file already in your Drive or click Upload to push a local file. Files >25 MB will skip the regular paperclip path and route through this dialog automatically.
After the file uploads, choose how it is inserted:
- Drive link — recipient clicks through to view in Drive. Required for files >25 MB.
- Attachment — only available if the file is under 25 MB and you want it sent as a normal attachment instead of a Drive link.
Before send, Gmail checks recipient permissions. If the file is not yet shared with everyone in the To: line, a dialog asks: Share with everyone? Pick View, Comment, or Edit access. If you skip this, recipients will see a “Request access” wall when they click the link.
Send. The recipient receives a small email containing a Drive link card with the file name, size, and a thumbnail.

Gmail Android and iOS follow the same flow — the paperclip menu offers both Attach file and Insert from Drive, and selecting a file >25 MB silently switches to the Drive flow.

Sharing pitfalls to avoid:

If you send a Drive link to an external (non-Workspace) recipient and forget to set permissions, they get the “Request access” page. Always pick Anyone with the link for ad-hoc sends, or pre-share the file with the recipient’s email if you want stricter control.
If you later delete the file from your Drive, the recipient’s link breaks. Drive links are live pointers, not snapshots. For files you want the recipient to keep permanently, ask them to download a copy after they receive the link.
Drive files counted against your storage quota are shared from your account. If you go over quota and the account is deleted, the link breaks. Long-term archival of important files is the recipient’s responsibility, not yours.

The 5 TB Drive per-file cap is documented in Google’s Drive file-types help page and applies to any non-Google-format file. Google Docs, Sheets, and Slides have their own format-specific limits (much lower) but those rarely matter for email overflow.

Compressing, splitting, or third-party transfers

Three workarounds when Drive is not an option: compress the file (ZIP, 7z, or video re-encode) to drop below 25 MB, split a single large file into parts and send sequentially, or use a third-party transfer service (WeTransfer, Smash, Send Anywhere, Proton Drive). Each has different recipient-side friction and privacy implications — pick based on the recipient’s environment, not just the file size.

Option 1 — Compression. Works well for documents, source code, raw text, and uncompressed image formats. Useless for files already compressed (MP4, JPEG, ZIP, 7z, modern Office formats). A 30 MB folder of TXT or CSV files often compresses to 6 MB; a 30 MB MP4 video compresses to 30 MB plus 200 KB of ZIP overhead. Test before relying on it.

For video specifically, re-encoding is the lever, not compression. Handbrake or ffmpeg can drop a 100 MB iPhone clip to 15 MB at H.265 with no perceptible quality loss for screen viewing. That is the real path to sub-25 MB video.

Option 2 — Splitting. 7-Zip and WinRAR both offer “split into volumes” — pick 20 MB per volume to leave headroom for MIME encoding. The recipient downloads all parts, places them in the same folder, and the archive tool reassembles them. Friction: high. Use only if neither side can install Drive or a third-party transfer client.

Option 3 — Third-party transfer services. When Drive is blocked (corporate IT, recipient’s policy) or the recipient wants a download link without a Google account:

Service	Free tier	Paid cap	E2E encryption	Recipient friction
WeTransfer	2 GB	200 GB	No (Pro: yes)	Click link, download
Smash	No size limit, ad-supported	Unlimited	Optional	Click link, download
Send Anywhere	10 GB free	Unlimited	Yes (E2E)	6-digit code or link
Proton Drive	1 GB	500 GB+	Yes (E2E)	Click link, optionally password
Firefox Send	Discontinued 2020	—	—	—
Microsoft OneDrive	5 GB	1 TB+	At rest	Microsoft account preferred

For one-off sends to a non-Google recipient, WeTransfer and Smash are the lowest-friction options — they generate a download link in under a minute, no recipient signup required.

For confidential transfers, Proton Drive’s E2E encryption means even Proton cannot read the file. Send Anywhere offers similar protections via direct device-to-device transfer when both parties are online.

For repeated sends to the same recipient, a shared cloud folder (Drive, OneDrive, Dropbox) is lower-friction than generating a fresh transfer link every time. Set up the share once, drop files in, the recipient subscribes to changes.

Receiving limits and what happens to oversized inbound mail

Gmail accepts inbound messages up to approximately 50 MB total. Messages exceeding that limit are rejected at the SMTP layer with a 552 5.3.4 “message size exceeds fixed maximum” error, and the sender’s server returns a non-delivery report (NDR). The 50 MB inbound is non-configurable on free Gmail; Google Workspace admins can adjust the inbound limit upward in some cases — see the admin section.

The receive cap matters because senders on other email systems may legitimately push messages above 25 MB. Some on-premise Exchange systems default to 35 MB outbound; some marketing platforms push large image-heavy messages. Gmail’s 50 MB inbound ceiling means it will accept those without bouncing, even though Gmail’s own outbound is 25 MB.

What happens at the boundary:

Under 25 MB inbound: delivered normally to the inbox.
Between 25 and 50 MB inbound: delivered. The recipient sees a normal email with a (possibly large) attachment.
Over 50 MB inbound: rejected at the receiving SMTP server with a 552 error. The sender gets a bounce message within minutes naming the size limit. The message never reaches the recipient’s inbox.

If you are expecting a large file from someone and they say it bounced: ask them to reroute through a Drive, OneDrive, or transfer service link. There is no way to “raise” the 50 MB inbound cap for a free Gmail account — the only option is to accept the file by another channel.

For Workspace accounts, admins can configure the inbound limit higher (up to a hard ceiling Google does not publicly commit to in writing), but the practical default ceiling for most Workspace inbound is the same 50 MB. Outbound stays 25 MB regardless of plan.

Mobile vs desktop — same limit, different friction

The 25 MB outbound cap is identical on Gmail web, Gmail Android, Gmail iOS, and any third-party mail client connecting via smtp.gmail.com. The difference is friction: Gmail web has explicit Drive and paperclip buttons in the compose toolbar; mobile apps consolidate both into a single attachment menu that auto-switches to Drive flow when the file exceeds 25 MB.

Gmail web (desktop browser):

Paperclip icon → file picker → if >25 MB, paperclip dialog asks to upload to Drive instead.
Drive icon → direct Drive picker, file already in Drive or upload now.
Compose footer warns “File too large — upload to Drive?” if you drag-and-drop a >25 MB file.

Gmail Android / iOS:

Single paperclip / attachment icon in compose toolbar.
Tap → menu shows “Attach file” (camera roll, files app) and “Insert from Drive.”
Files >25 MB picked from local storage trigger an automatic switch to Drive upload — no separate user action needed.
Mobile data warning: large uploads use cellular bandwidth unless on Wi-Fi. Gmail iOS does not block uploads on cellular by default.

Third-party clients (Apple Mail, Outlook, Thunderbird via SMTP):

These connect to smtp.gmail.com:587 (TLS) or smtp.gmail.com:465 (SSL).
The 25 MB cap is enforced at smtp.gmail.com itself, not at the client. The client may let you compose a 100 MB attachment, but the SMTP server will reject the SEND with a 552 error.
Workaround: most third-party clients have a separate “OneDrive / iCloud / Drive Mail Drop” mechanism. Apple Mail’s iCloud Mail Drop, for example, hosts files up to 5 GB and drops a link in the message body — analogous to Gmail’s Drive flow but using Apple infrastructure.

The takeaway: there is no client-side trick that raises the cap. It is enforced at Google’s servers, on every channel.

When the file is sensitive — confidential mode and encrypted alternatives

For sensitive files, Gmail’s confidential mode adds expiration, passcode protection, and disabled forwarding to the email itself, but does not add end-to-end encryption — Google can still read the message. For true E2E encryption, use Drive with restricted permissions plus client-side encryption (PGP, ProtonMail, or Tresorit), or transfer through Proton Drive / Tresorit Send.

Confidential mode (the lock-and-clock icon in the compose toolbar) does three useful things and one limited thing:

Expiration: the message becomes unreadable after 1 day to 5 years.
SMS passcode: recipient must verify a code sent to their phone.
Disabled actions: recipient cannot forward, copy, print, or download.
Not E2E encrypted: the message contents pass through Google’s servers in a form Google can decrypt.

If your threat model is “casual snooping / accidental forwarding,” confidential mode is sufficient. If your threat model is “no third party including Google should read this,” confidential mode is the wrong tool — you need E2E encryption.

For E2E with large files, the options are:

ProtonMail + Proton Drive. Both endpoints in the Proton ecosystem. Send up to 25 MB attachments E2E encrypted in the email itself; for >25 MB, use Proton Drive’s share link feature with end-to-end encryption.
PGP / GPG. Encrypt the file locally with the recipient’s public key, then send via Drive or any transfer service. The hosting provider sees only the encrypted blob.
Tresorit Send. Up to 5 GB per send, end-to-end encrypted, recipient gets a download link with optional passcode and expiration.

For Workspace admins handling regulated data (HIPAA, GDPR), Google’s S/MIME or third-party DLP tools layered over Gmail are the supported paths. Free Gmail does not offer S/MIME.

Workspace admin settings that change the inbound limit

Google Workspace admins can adjust the inbound message size limit in the Admin console under Apps → Google Workspace → Gmail → Compliance / Routing rules. The outbound 25 MB cap is fixed at Gmail’s SMTP layer and cannot be raised by admins. Inbound caps can typically be lowered to enforce stricter policy or raised to a Google-defined ceiling for organizations expecting large legitimate inbound.

What admins can change:

Inbound message size routing rules. Reject inbound messages over a chosen threshold (lower than 50 MB) for compliance reasons.
Quarantine for large messages. Route large inbound to a quarantine queue for admin review.
Attachment compliance rules. Block specific file types regardless of size (executables, scripts, archives matching certain patterns).
Retention. Set retention rules that auto-purge attachments older than a defined period.

What admins cannot change:

The 25 MB outbound cap. Hard-coded at smtp.gmail.com. No Workspace tier raises it.
Drive’s 5 TB per-file cap. Hard-coded in Drive itself. Some Workspace tiers raise per-user storage, but not per-file.
Confidential mode availability. Either on for the org or off — but the “off” setting blocks users from sending confidential messages, it does not add encryption.

For organizations that frequently need to send files >25 MB by email, the supported pattern is: provision Workspace, enable Drive sharing with external collaborators, and train senders to use the Drive flow. Outbound 25 MB is the constant.

A related read: if your account routinely hits storage caps from sent attachments, run through the Gmail storage full guide and the find-and-delete-large-emails playbook — Gmail counts every Drive file you sent toward the same 15 GB pool. For automating the long-term hygiene around attachments and senders, building Gmail filters that label or auto-archive large messages is the lowest-friction lever.

Alexis Dollé

Founder & Editor

Alexis Dollé, email expert for 10+ years. Founder of Email Tools. I test every email client and utility myself, then write about them the way I’d explain them to a friend — no marketing fluff, no sponsored rankings, every claim sourced.

Sources & references

Google, “Files you can attach to Gmail messages” — official 25 MB outbound limit and Drive overflow behavior. support.google.com/mail/answer/6584
Google, “Files you can store in Google Drive” — 5 TB per-file cap for non-Google-format files. support.google.com/drive/answer/37603
Google, “Send & save attachments in Gmail” — compose-side mechanics, Drive integration. support.google.com/mail/answer/9261412
Google, “Send & open confidential emails” — confidential mode capabilities and limitations. support.google.com/mail/answer/7674059
Google Workspace Admin Help, “Email size limits” — admin-side inbound limits and routing. support.google.com/a/answer/1366776

Frequently asked questions

What is the maximum attachment size in Gmail?

Gmail caps outgoing messages at 25 MB total — that includes the email body, every attachment, and the MIME encoding overhead. Files larger than 25 MB are automatically uploaded to Google Drive and inserted into the message as a sharable link, with the recipient’s permissions handled in the compose dialog. The receiving cap is higher — Gmail accepts inbound messages up to roughly 50 MB.

Can I increase the 25 MB Gmail send limit as a Workspace admin?

No. The 25 MB outbound cap is enforced at Gmail’s SMTP layer, not at the workspace level. Even Google Workspace Enterprise admins cannot raise it. The supported path for files above 25 MB is the built-in Google Drive integration, which accepts files up to 5 TB at the Drive layer.

Why does Gmail say my 24 MB file is too big?

MIME encoding inflates raw file size by about 33 percent. A 24 MB file becomes roughly 32 MB on the wire after Base64 encoding, and Gmail measures the encoded size, not the raw size. To stay under 25 MB without Drive, target raw files of about 18 MB or less.

How do I send a 100 MB or larger file from Gmail?

Use the Google Drive integration — click the Drive icon in the compose toolbar, upload the file, and Gmail inserts a sharable link in the body. Set the recipient’s access (View / Comment / Edit) before sending. Drive accepts files up to 5 TB per file, far more than any email transport will handle.

Are there alternatives to Drive for sending large files?

Yes — WeTransfer (free up to 2 GB), Smash (no size limit on the paid tier), Send Anywhere (up to 10 GB free), Proton Drive (free up to 1 GB), and Microsoft OneDrive (when the recipient runs Microsoft 365). Each generates a download link you paste into Gmail. Pick based on whether the recipient needs a Google account, a download link, or end-to-end encryption.

Does the 25 MB limit apply to Gmail mobile too?

Yes. The 25 MB outbound cap is enforced server-side, so the limit is identical on Gmail web, Gmail Android, Gmail iOS, and any IMAP/SMTP client connecting via smtp.gmail.com. Mobile apps simply trigger the same Drive upload flow when the file exceeds 25 MB.

Related: Gmail storage full — what to do, how to create a filter in Gmail, and how to find and delete large emails — same Gmail toolkit, different angles.