SRT vs RTMP: which protocol, and why
SRT and RTMP both carry a live stream, but they behave very differently on mobile data. Here is what each one is, in plain English, and why it matters for IRL.
The quick answer
For streaming over mobile data, which is what IRL is, SRT wins. RTMP is fine on a stable wired connection, but it struggles the moment the network wobbles. If you are out and moving, that wobble is constant, so SRT is the protocol you want.
What is RTMP
RTMP, or Real-Time Messaging Protocol, is the long-standing streaming standard. It has been around for years, and plenty of encoders and platforms still speak it.
The catch is what it was built for: stable, wired connections. RTMP has no real recovery when packets are lost. On a solid wired link that is rarely a problem, but a shaky mobile connection makes it stutter or drop the stream entirely.
What is SRT
SRT, or Secure Reliable Transport, is a modern protocol designed for exactly the networks RTMP struggles on: unstable ones. When packets go missing, SRT re-sends them within a short time window you set, so a bumpy mobile connection still arrives clean at the other end.
There is also SRTLA, which is SRT with bonding added. It can spread your stream across several connections at once, which is what keeps you live as you move. See the what is bonding guide for how that works.
Why SRT is better for IRL
- Recovers from packet loss by re-sending what goes missing, so brief signal gaps do not break the stream.
- Tolerates a changing signal as you move between cells, buildings, and dead spots.
- Supports bonding via SRTLA, so you can combine several connections for extra resilience.
- Keeps latency low and predictable, which matters when you are talking to a live chat.
Where RTMP still fits
RTMP has not disappeared. Some cameras and encoders only output RTMP, and that is fine.
Super Simple IRL can take an RTMP feed in from a GoPro or DJI camera, then send SRT or SRTLA out to your relay. So you can use your existing RTMP gear on the way in, and still get SRT’s reliability on the outbound stream. You get the best of both: the camera you already own, and a protocol that holds up on mobile data.
Frequently asked questions
Is SRT better than RTMP?
For streaming over mobile data, yes. SRT recovers from lost packets and tolerates a wobbly signal, while RTMP has no real recovery. On a stable wired connection, RTMP is perfectly fine.
Why does RTMP drop on mobile data?
RTMP was built for stable, wired connections and has no way to recover lost packets. When a mobile signal wobbles and packets go missing, the stream stutters or drops.
Does Super Simple IRL use SRT or RTMP?
It sends SRT, or SRTLA when bonding, out to your relay. It can also take an RTMP feed in from a camera, so you get RTMP gear support with SRT reliability on the outbound stream.
Can I still use my RTMP camera?
Yes. Super Simple IRL can take an RTMP feed in from a GoPro or DJI camera, then send SRT or SRTLA out to your relay. Your camera stays RTMP, your stream gets SRT's reliability.