Compress preset

Compress Video for Email

25 MB targetGmailH.264 MP4

Email still trips on video attachments. Gmail stops at 25 MB of total message size, which after base64 encoding overhead means the raw video can be at most roughly 19 MB. Outlook.com and most Microsoft 365 mailboxes cap attachments at 20 MB. Corporate Exchange servers commonly enforce stricter 10 MB limits at the gateway, and ProtonMail Free sits at 25 MB too. This tool compresses any source video to hit the exact ceiling of the mail client you are sending through, with a conservative 10 MB fallback when you are not sure what the recipient's mail server allows.

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Compressing for Email in detail

The output is standard MP4 with H.264 and AAC so the file opens the moment your recipient clicks the attachment. No plugins, no codec installs, no "download Divx" popups that used to plague video-by-email ten years ago. Because the encoder does a two-pass analysis, the quality you get at a 25 MB target is about as good as video quality gets at that size for a one to two minute clip.

Privacy matters in email more than most channels. Signed quotes, client onboarding walkthroughs, and medical intake videos often end up attached to messages. Running the compression locally means the source file never leaves your machine during the process. The only copy of the compressed MP4 goes where you send it.

Attachment limits by mail provider

Setting	Value	Notes
Gmail	25 MB per message	Total message size including base64 overhead.
Outlook.com	20 MB per message	Personal Microsoft 365 mailboxes.
Microsoft 365 business	20 to 150 MB	Default 25 MB; admin can raise up to 150 MB.
Corporate Exchange	10 to 25 MB	Varies by IT policy; 10 MB is the common gateway default.
ProtonMail Free	25 MB per message	Same ceiling as Gmail on the free tier.
Apple iCloud Mail	20 MB per message	Larger files route through Mail Drop automatically.

When to use this preset

Client onboarding walkthroughs

Record a five minute product walkthrough and squeeze it into a Gmail-safe 25 MB so new customers can watch inline without a Loom account.

Signed quote explainers

Attach a short screencast explaining line items of a quote, keep it under 20 MB for Outlook-heavy prospects, and skip the meeting.

Status updates to stakeholders

When a Slack message is not formal enough, a 25 MB video attached to an email lands as a deliverable in the inbox with full context.

Support bug recordings

Compress a 1080p OS-level screen recording down to 10 MB so it passes through strict corporate mail gateways on the first try.

HR and legal evidence clips

Preserve a clip as an email attachment for audit trails; a 25 MB file is small enough to archive but readable enough to review later.

Frequently asked questions

What is the maximum video attachment size for Gmail?

Gmail allows messages up to 25 MB total, which includes the body, headers, and every attachment after base64 encoding. Because base64 inflates binary data by about 33 percent, the raw video can be at most around 19 MB. Compressing to 19 or 20 MB leaves safe headroom for the encoded message envelope.

How do I email a large video?

You have two choices. Either compress the video to fit your provider's cap using this tool, or upload it to a cloud link like Google Drive and paste the share URL into the email. Compression keeps the video as a true attachment, which recipients treat as part of the message, while a link gives them one more thing to click.

What is the Outlook attachment size limit?

Outlook.com personal mailboxes limit attachments to 20 MB per message. Microsoft 365 business accounts default to 25 MB but the administrator can raise the limit up to 150 MB. Corporate Exchange servers often enforce stricter caps at the gateway, sometimes as low as 10 MB, regardless of what the Outlook client shows.

Can I send a video larger than 25MB in Gmail?

Not as a direct attachment. Gmail will prompt you to upload the file to Google Drive and send it as a share link instead. If you want a true attachment rather than a link, compress the video below 19 MB of raw data so the fully encoded message fits within the 25 MB transport limit.

What format should I send video in email?

MP4 with H.264 video and AAC audio. Every modern mail client previews MP4 inline, and every operating system plays the file with the default media player when the attachment is saved. Avoid MOV for Windows recipients, MKV for any recipient, and WMV for anyone on a Mac or phone.

Does email compress video attachments?

No. Mail servers do not re-encode attachments. They forward the bytes as-is and enforce the total message size limit before delivery. That means the 30 MB video that failed to send will still be 30 MB at every hop. Compressing client-side is the only way through.

Why was my video email rejected?

Almost always because the total message exceeds the recipient's mail server limit. Even if your outbound server accepts the message, the receiving server may reject it. When in doubt, compress to the conservative 10 MB target, which fits nearly every corporate Exchange policy in the wild.

100% Private: Your Video Never Leaves Your Device

Compression runs locally in your browser using FFmpeg compiled to WebAssembly. Your video file is read from disk into browser memory, processed there, and the result is saved back to your device. No network request is made during encoding, no data is transmitted, and no server ever sees your footage.