RM to MP4 converter
Convert RM to MP4 in your browser. No upload and no account: the file never leaves your device, so the only size limit is your device’s memory.
Fit Meter
Applies only when the video has to be re-encoded. A straight copy keeps the original quality.
Advanced 2
Bytes of your files sent anywhere: 0 B · nothing leaves this tab
Every request this page makes is listed as it happens. You’ll see our own code loading, and for some formats a codec engine, but never your file going out.
- Waiting for network activity…
Check it yourself: open your browser’s developer tools on the Network tab, or turn off Wi-Fi once the page has loaded. The tools keep working.
Related conversions
Convert other formats to MP4
Read more about the RM format and the MP4 format, or see every video tool and all video conversions.
Should you convert RM to MP4?
Yes, when a device or app needs MP4. MP4 can’t carry the RealVideo video found in RM files, so the picture is re-encoded as H.264 or HEVC (H.265), which takes about as long as the clip on a recent laptop.
MP4 also plays in far more places: every phone, browser, TV, editor, chat app and upload form.
RM is RealNetworks’ streaming video format from the dial-up era; MP4 is the video container that plays on everything, usually holding H.264 video and AAC audio. Use MP4 whenever a video has to be sent, uploaded or played somewhere you don’t control.
| Property | RM | MP4 |
|---|---|---|
| Usually contains | RealVideo with RealAudio (Cook) audio | H.264 or HEVC video with AAC audio |
| Support | A legacy format | Opens everywhere |
| Plays on | VLC and RealPlayer; nothing modern supports it | Every phone, browser, TV, editor, chat app and upload form |
| Best for | Nothing today; convert old downloads and archives | Sharing video anywhere |
| Introduced | 1997 | 2003 |
How to convert RM to MP4
- 01
Add your RM
Drop your RM video onto the box, or click to choose it. It is read from your disk and stays there.
- 02
Check the settings
The output is already set to MP4. Change the quality if you want to; the defaults suit most files.
- 03
Save the MP4
Press convert and save the MP4. Several files come back together as a ZIP.
What changes when RM becomes MP4
Re-encoded, at a quality you choose
Because the video has to be compressed again, a little detail is lost. The default quality keeps the difference invisible; choose High for footage you’ll edit further.
Expect a larger file
MP4 generally takes more room than RM. If the file has to fit an upload limit, check the size once it’s converted. RM: Small, and low quality by modern standards. MP4: 1080p phone video runs roughly 60–130 MB a minute.
A one-time engine download
RM is read by FFmpeg compiled to WebAssembly, a 31 MB download the first time. It is slower than your browser’s built-in video decoder, but nothing is uploaded and the engine stays cached for next time.
This page is put together from our notes on each format, choosing only what is true of RM and MP4, so every pairing states the same facts the same way. How these pages are made.
Why it doesn’t upload
Video files are big, and uploading one just to change its container can take longer than the conversion itself. Your browser can read and write these formats, so the file never has to leave your device.
How to check for yourselfWorth knowing
- About the RM. RMVB files use variable bitrate and play at the wrong speed in some tools; converting gives a normal, steady MP4.
- About the MP4. An MP4 that won’t play is rarely broken; it usually holds a newer codec such as HEVC or AV1 that the player doesn’t support.
- MP4, MOV, MKV and WebM are handled by your browser’s own video engine, often with hardware help. AVI, WMV, FLV, MPG and the other older formats use the FFmpeg engine, a one-time 31 MB download, and are slower.
Questions
Does converting RM to MP4 lose quality?
The video is re-encoded, so a little detail is lost, but the default quality is set high enough that it doesn’t show.
Will a MP4 play on my phone?
MP4 opens everywhere: every phone, browser, TV, editor, chat app and upload form. Every device plays MP4: double-click it, or drag it into a browser tab.
Read more about this
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