What opens, what refuses, and why
One page per format: what the thing actually is, whether an iPhone, iPad or Mac reads it without help, what usually turns out to be inside it, and what your options are when it will not play. Written as a reference rather than a pitch — most of these formats have nothing to do with us.
Every format at a glance
| Format | Kind | iOS | macOS | FoxDL |
|---|---|---|---|---|
| MKV | Container | Refuses | Refuses | Opens |
| MP4 / MOV | Container | Opens | Opens | Opens |
| AVI | Container | Refuses | Refuses | Opens |
| WebM | Container | Partly | Partly | Opens |
| M3U8 / HLS | Stream | Opens | Opens | Opens |
| M3U | Playlist | Refuses | Refuses | Opens |
| TS / M2TS | Container | Refuses | Refuses | Opens |
| FLV | Container | Refuses | Refuses | Opens |
| WMV | Container | Refuses | Refuses | Opens |
| FLAC | Audio | Partly | Partly | Opens |
| SRT / ASS / VTT | Subtitles | Partly | Partly | Opens |
“Native” means the system itself opens the file: the Files preview, QuickTime, the Photos player. It says nothing about what a third-party app can do, which is the whole reason players like this one exist.
Containers
MKV
The container that holds everything, and that Apple never taught its systems to read.
MatroskaMP4 / MOV
The formats your iPhone does open — which makes it stranger when one of them will not.
ISO base mediaAVI
Thirty years old, still on every external drive, and opened by almost nothing.
Audio Video InterleaveWebM
A format the web plays constantly and the operating system still cannot open.
VP8, VP9, AV1TS / M2TS
Built for broadcast, where the receiver may join halfway through and nothing has an end.
MPEG Transport StreamFLV
The format that was the internet for a decade, outliving the technology that made it.
Flash VideoWMV
Microsoft video in a Microsoft wrapper, on a platform that stopped building bridges.
Windows Media