---
url: https://doc.moq.dev/bin/hls.md
description: Serve any broadcast as HLS, or import an HLS playlist
---

# HLS

`moq export hls` serves a MoQ broadcast as HLS over HTTP for players that
can't speak MoQ. `moq import hls` pulls a remote HLS master or media playlist
into a broadcast.

```bash
# Serve. Players open http://localhost:8089/my-stream.hang/master.m3u8
moq --connect https://relay.example.com/anon --broadcast my-stream.hang export hls --listen '[::]:8089'

# Import
moq --connect https://relay.example.com/anon --broadcast my-stream.hang import hls https://example.com/live/master.m3u8
```

Export never subscribes to media. It reads the broadcast's
[timeline track](/concept/hang#catalog), a log of complete segments aligned
across every rendition, to build playlists, then fetches exactly the groups a
requested segment covers from the relay's cache and transmuxes them to CMAF on
demand. So a segment is servable for as long as the relay's
[cache](/bin/relay/config#cache) retains it, and idle renditions cost nothing.
Because segments are aligned, the same number names the same span of content in
every media playlist; a record with nothing for a rendition renders as
`EXT-X-GAP` and a jump in content time as `EXT-X-DISCONTINUITY`. A broadcast
whose catalog advertises no timeline is skipped. One server exposes every
broadcast by path:

```text
/{broadcast}/master.m3u8
/{broadcast}/manifest.mpd
/{broadcast}/{video|audio}/{rendition}/media.m3u8
/{broadcast}/{video|audio}/{rendition}/init.{hash}.mp4
/{broadcast}/{video|audio}/{rendition}/seg/{segment}.m4s
/{broadcast}/{video|audio}/{rendition}/seg/t{pts}.m4s
```

The init URL carries a hash of its bytes, so a reconfigured rendition gets a
new one. An embedder of the library can also label the publisher's run with
`Broadcaster::set_generation`. Every segment URL then carries it
(`seg/{generation}.{segment}.m4s`), since a restarted publisher reuses segment
numbers for different media.

`--window` sets the playlist duration (default 16 s),
`--listen-tls-cert`/`--listen-tls-key` or `--listen-tls-generate` serve HTTPS,
and `--cors-origin` opens it to browsers.
H.264/H.265 and AAC/Opus renditions are served. Import handles classic HLS;
LL-HLS parts are not implemented yet. The library is
[`moq-hls`](https://docs.rs/moq-hls).