Compress video for Email (Gmail)
Gmail publishes a 25 MB attachment limit, but that applies to the encoded message. Base64 encoding inflates a file by about a third, so the largest file that reliably sends is closer to 18 MB.
This page targets 17.5 MB, verified against Gmail Help — Send attachments with your Gmail message.
- Uploaded to a server
- 0.00 KB
- Processing
- WebAssembly, this device
- Offline engine
- warming up
Don't take our word for it — check it yourself in DevTools.
The number most tools give you is wrong
- Commonly published
- A 24 MB video will send through Gmail because the limit is 25 MB.
- Actually
- It will usually bounce. Plan for about 18 MB of actual file.
- Why the confusion
- Attachments are transmitted as Base64 text, which is roughly 33% larger than the binary file, plus MIME headers. The published limit is measured after that expansion. This is also why the same file can succeed to one recipient and fail to another: delivery is governed by the smallest limit anywhere in the chain, and Outlook's desktop client applies 20 MB.
Email (Gmail) limits in full
| Platform | Tier | Limit | Applies to | Source |
|---|---|---|---|---|
| Email (Gmail) | Gmail, personal account Published cap. Applies to the encoded message, not the file you attach. | 25 MB | People | Gmail Help — Send attachments with your Gmail message primary checked Quoted verbatim: "For personal Gmail accounts, the limit is 25 MB." |
| Email (Gmail) | Gmail, practical file ceiling | 18 MB | People | Gmail Help — Send attachments with your Gmail message secondary checked Derived, not published: 25 MB divided by the ~1.37x Base64 + MIME overhead. Google documents the 25 MB cap but does not state the encoded-size behaviour on that page. |
Rows marked API only apply to bots and integrations, not to messages you send yourself. Mixing those two up is the single most common source of wrong advice about file sizes.Compare every platform →
Questions
Is it true that A 24 MB video will send through Gmail because the limit is 25 MB?
It will usually bounce. Plan for about 18 MB of actual file. Attachments are transmitted as Base64 text, which is roughly 33% larger than the binary file, plus MIME headers. The published limit is measured after that expansion. This is also why the same file can succeed to one recipient and fail to another: delivery is governed by the smallest limit anywhere in the chain, and Outlook's desktop client applies 20 MB.
Does compressing for Email (Gmail) upload my video?
No. The encoder runs in your browser through WebAssembly. Your video and the compressed result stay on your device; only the encoder itself is fetched, once.
What size should I target for Email (Gmail)?
We target 17.5 MB, slightly under the published limit of 25 MB. Bitrate-based encoding cannot hit a size exactly, and a file one byte over the cap is a failed upload.