Compress a video for email
Get a video under the 25 MB attachment limit so it sends as a normal attachment, not a cloud link.
- Nothing is uploaded
- Works offline after first visit
- Open source
- No watermark · limit is your device’s memory; phones hold less
Shrink a video under the 25 MB attachment limit of Gmail and Outlook, in your browser. It is free, needs no account and adds no watermark, and your files are not uploaded: everything runs in your browser on your device. The size limit is your device’s memory, and phones hold less; give the page a short while after one visit to save itself for offline use, and then it works offline.
Your iPhone may take a few seconds to prepare the video first, longer if it's stored in iCloud.
Done
Open the network tab. Your files never appear in it.
Add files and run the tool to see every request this tab makes.
Your files are processed on this device and never sent to a server. Reload the page to clear everything from memory.
Gmail and Outlook.com accept attachments up to 25 MB in total, and anything larger is turned into a Drive or OneDrive link that the recipient has to open, and which may need them to sign in. A phone video passes 25 MB in about 15 seconds. Compress it here to fit, and it arrives as a normal attachment that plays in the email.
Choose the size, drop the video, and the page sets the bitrate from the length of the clip, lowering the resolution only if the video is long. A 2 to 3 minute clip fits at 720p, which looks fine in a mail app. Leave a little room if you are attaching other files as well: the 25 MB limit counts everything in the message.
The video is compressed in your browser tab. Family videos and work recordings are never uploaded to a converter site, and there is no account or watermark.
Email adds overhead of its own. Attachments are converted to text for sending, which makes them about a third larger. Gmail and Outlook.com check the size of the files as you attach them, but the mail server at the other end may measure the encoded message, and company or school servers often have lower limits than 25 MB. If a video sends fine but bounces back from a work address, compress it again at 16 MB, which stays under 25 MB even after encoding.
For a screen recording, such as a bug report or a walkthrough for a colleague, set Resolution to 720p and tick Remove the sound if you did not talk over it. Dropping the sound track leaves more of the limit for the picture, which helps keep on-screen text readable. Longer recordings fit too: the page can squeeze up to about 16 minutes into 25 MB before it asks you to trim, though by then the picture is small.
How it works
- Drop the video, or tap to pick it.
- 25 MB is selected. Pick 16 MB or less if you are attaching other files too.
- Compress, then attach the MP4 to your email.
In your browser, not on a server
Mediabunny (MPL-2.0), a media toolkit written in TypeScript, reads the MP4, MOV, WebM or MKV container in your tab. Your browser’s own hardware-backed video decoder and encoder (WebCodecs) re-encode the picture at the bitrate and size you chose, H.264 where available and VP9 or AV1 otherwise, and the sound as AAC or Opus. Mediabunny then writes a new MP4 in memory. For a target size, the bitrate is worked out from the length of the video, and the resolution is lowered when a long video would otherwise turn to mush.
Compared with upload-based tools: Online compressors upload the whole video before they start, cap free files at a few hundred megabytes, and often add a watermark or a queue. Phone videos are some of the most personal files people have. Here the video never leaves your device, and a 2 GB file is compressed as fast as your computer can encode it.
Verify it yourself. Give the page a short while after one visit to save itself for offline use, then turn off Wi-Fi or switch to airplane mode and run the tool again. Or open your browser's developer tools (F12, or Cmd-Option-I on a Mac), pick the Network tab, and watch it while you convert. The panel above does the same count for you.
Questions
What are the email attachment limits?
Gmail and Outlook.com: 25 MB per message. Outlook for work accounts is often 20 to 35 MB, set by your organisation. iCloud Mail: 20 MB, or Mail Drop links for larger files. Yahoo: 25 MB.
Will the video play in the email?
Yes. The result is an MP4 with H.264 video in browsers that can write it (Chrome, Edge, Safari), which plays in Gmail, Outlook, Apple Mail and on every phone.
What if the video will not fit in 25 MB?
Split it, or send a link after all. Trim video can cut a long recording into two or three parts that each fit, and you send them as separate emails, since the limit applies to each message. Otherwise use the cloud option your mail app offers: Google Drive in Gmail, OneDrive in Outlook, or Mail Drop in Apple Mail, which takes files up to 5 GB.
How do I fit several videos in one email?
The 25 MB counts everything in the message, so divide it between the clips: 10 MB each for two, 8 MB each for three. Drop all the videos at once and each is compressed to that size and saved separately, ready to attach together. Each result shows its new size, so you can add them up before you press send.
Is the file uploaded anywhere?
No. There is no server in this process. The page is a static file and the work is done by code running inside your browser tab. Give the page a short while after one visit to save itself for offline use; then you can turn off Wi-Fi and it still works.
More video and audio tools
Compress video
Make a video a fraction of the size, or fit it under a limit like 10 MB for Discord or 25 MB for email. It is compressed on this device and never uploaded.
Merge audio
Combine songs, voice notes or podcast segments into one file. Done on this device, never uploaded.
Mic test
Check that your microphone works before a Zoom, Teams or Discord call: speak and watch the level, then play back five seconds to hear how you sound. Nothing is uploaded.
Webcam test
Check that your webcam works before a Zoom, Teams or interview call: see the live picture, the real resolution and the measured frame rate. Nothing is uploaded.
Other conversions
Guides
- How to compress a video without losing qualityMost phone video is recorded at a far higher bitrate than the screen needs. Here is what to change, and what actually loses quality.
- How to turn audio into a videoTo put a song, a podcast episode or a voice note on YouTube, you need a video. Here is how to make one from the sound and a single picture.
- How to resize a videoGetting a video down from 4K to 1080p, or to an exact width and height a platform expects, is a different setting than just compressing it. Here is how, in the browser.