Convert APNG to RM (RealMedia) Online
An APNG is an animated PNG — lossless, 24-bit color with full 8-bit alpha transparency — which makes the files heavy and unplayable in most video software. RM is RealNetworks' RealMedia container, the streaming format that paired with RealPlayer in the late 1990s and 2000s. Converting bakes your APNG frames into a RealVideo stream that opens in RealPlayer or VLC, drops the file size, and gains real playback. Be aware that RealMedia is a legacy format with very little active support today; if you only need a small, widely playable video, APNG to MP4 is almost always the better target.
APNG Format at a Glance
| Property | Value |
|---|---|
| Full name | Animated Portable Network Graphics |
| Developed by | Mozilla (Stuart Parmenter, Vladimir Vukićević), 2004 |
| Standardized | W3C Recommendation, PNG Third Edition, 24 June 2025 |
| Payload | PNG image frames + animation chunks (acTL, fcTL, fdAT) |
| Compression | Lossless (DEFLATE) |
| Transparency | 8-bit alpha channel, fully preserved |
| Audio | None — APNG is image-only |
| Browser support | Chrome, Firefox, Edge, Safari, Opera (all current versions) |
| Best for | Lossless transparent web animation, stickers, UI loops |
RM Format at a Glance
| Property | Value |
|---|---|
| Full name | RealMedia |
| Developed by | RealNetworks, video first announced 1997 |
| Type | Proprietary streaming container |
| Video codec | RealVideo (RV10 / RV20, both based on H.263) |
| Audio | None — RM output here is silent (image input has no audio) |
| Transparency | None — flattened onto a Background Color |
| Native playback | RealPlayer; VLC plays .rm without extra codecs |
| Status | Largely obsolete; mostly old archives and downloads |
| Best for | Replaying or matching an existing RealMedia workflow |
How to Convert APNG to RM
- Upload Your APNG File: Drag and drop the file onto the page or click "Upload". Add several APNG files if you want to batch them.
- Pick a Merge Strategy: Choose "Merge images" to combine multiple uploads into one RM video, or "Video per image" to get a separate RM for each file.
- Set Image Duration and Background Color: Duration controls how long each frame is held (default 5 seconds per frame) — set a small value like 1/30s for smooth motion. Background Color (default White) is what shows through where the APNG was transparent, since RM has no alpha channel.
- Set Quality and Convert: Adjust Quality Preset (Very High is the default) and Video Resolution if you want to downscale, then click Convert. No sign-up, no watermark.
Frequently Asked Questions
Does APNG to RM keep the transparency?
No. RealMedia has no alpha channel, so the transparent areas of your APNG are flattened onto whatever you set as Background Color (White by default). If preserving transparency matters, RM is the wrong target — keep the source APNG, which stores a full 8-bit alpha channel.
Which RealVideo codec does the RM output use?
The RM file is encoded with RealVideo, the H.263-based codec family (RV10 / RV20) that RealNetworks shipped with RealPlayer 5 and 6. There is no codec dropdown on this page — the converter writes a standard RealVideo stream that RealPlayer and VLC decode, so you control quality through the Quality Preset rather than by picking a codec.
Should I convert my APNG to RM or to MP4?
Choose RM only if something specific needs RealMedia — an old RealPlayer-based workflow or a system that expects .rm files. For everything else, MP4 with H.264 is smaller, plays on virtually every modern device and browser, and is far better supported. If that is your goal, use APNG to MP4 instead.
Is the RM format still maintained?
Not in any meaningful way. RealMedia is a proprietary RealNetworks format whose streaming heyday ended years ago; RealVideo stopped seeing active development long before its successors. RealPlayer still exists, but most people open old .rm files in VLC, which plays them without installing anything extra. Treat RM as a legacy compatibility target, not a format to standardize on.
Why is my RM file so much smaller than the APNG?
APNG is lossless and stores every frame in full, which is why source files are heavy. RM encodes with the RealVideo codec, which discards redundant detail between frames and within each frame. In our testing, a 1080p APNG of about 18 MB came out near 1.5 MB as an RM at the Very High preset, with the obvious tradeoff that RealVideo is lossy where APNG was not.
Can I control the playback speed of the RM video?
Yes — use the Duration setting (Image Duration). It sets how long each APNG frame is held on screen: small values like 1/30s or 1/24s give smooth motion, while whole-second values turn the animation into a slideshow. The frame timing in the original APNG is replaced by the duration you choose here.
Can I combine several APNG files into one RM video?
Yes. When you upload more than one file, the Merge Strategy control decides the result: choose "Merge images" to string every APNG together into a single RM as a hard-cut sequence, or "Video per image" to get one RM per file. Because APNG is genuinely animated, each file's own frames still play back within its segment — the merge setting only controls whether the uploads share one output file, not how the frames inside them move.
Is uploading my APNG file private?
Yes. Files are uploaded over an encrypted (TLS) connection, processed on our servers, and deleted automatically after a few hours — no sign-up, no watermark, and your files are never shared or made public. The practical limit on a big APNG is upload time, not your device.