RM File Format (.rm)
An RM file is a RealMedia container from RealNetworks, holding RealVideo and RealAudio streams built for the dial-up era, when RealPlayer was how most people first watched video over the internet.
RM at a glance#
| Full name | RealMedia |
|---|---|
| File extension | .rm |
| Category | Video Files |
| Developer | RealNetworks |
| MIME types | application/vnd.rn-realmedia |
| Other extensions | .rmvb |
| Compression | Lossy |
| FileFlip support | FileFlip reads this format but does not write it |
What a .rm file can hold#
These are the things a RM file either supports or does not, and they are what decides whether a conversion keeps everything or quietly drops something.
| Embedded metadata | Yes |
|---|---|
| Audio | Yes |
| Video | Yes |
| Streaming | Yes |
Strengths and limitations of RM#
What RM does well
- RealVideo's aggressive compression was built specifically to survive dial-up and early broadband bandwidths
- RMVB, the variable-bitrate variant, spends more data on complex scenes and less on static ones, which was unusual for its era
Where RM falls short
- RealPlayer has not shipped for macOS since 2018, and only Windows, Android and iOS versions remain
- Browsers dropped RealMedia plugin support years ago, so an RM file no longer plays inline anywhere on the web
- Later RealVideo codec revisions (RV30, RV40) are only partially supported outside RealNetworks' own player
There is no current reason to create a new RM file; it only shows up now as something to get footage out of.
Convert RM to MP4 as soon as one turns up, since RealPlayer support keeps shrinking and most other software cannot open the format at all.
How to open a .rm file#
A .rm file opens in the programs below, grouped by the platform you are on. If you would rather not install anything, FileFlip converts RM into a format your machine already opens, and it does it in the browser tab rather than on a server.
| Platform | Programs that open it |
|---|---|
| Windows | RealPlayer, VLC |
| Linux | VLC, MPlayer |
| Web | FileFlip |
RM questions people ask#
What still opens an RM file?
VLC opens most RM files on Windows, macOS and Linux through its built-in libavformat decoder, which covers the common RealVideo codecs. RealPlayer itself still exists for Windows, Android and iOS, but RealNetworks stopped releasing it for macOS in 2018.
What should I convert an old RM file to?
MP4 with H.264 is the safe target for an old RM file, since it plays everywhere RealMedia no longer does, from phones to browsers to any current editing software.
Is RealMedia still used for anything?
No. RealMedia was the dominant streaming format before broadband made Flash and later HTML5 video practical, and it has had no meaningful new use since. An RM file today is almost always old footage someone is trying to recover, not something being created.
Converting RM files#
Convert RM to another format
FileFlip does not write .rm files, so nothing on the site converts into this format. It works as a source only.
Every conversion runs inside your browser. The file is read from your disk, the work happens on your own machine, and nothing is uploaded. How FileFlip works names the engine behind each family and how to verify that for yourself.