SRT vs RTMP: Which Streaming Protocol Should You Use in 2026?
The Protocol Dilemma
If you’re building a live streaming workflow in 2026, you’ve probably asked yourself: should I use SRT or RTMP? Both protocols move video from point A to point B, but they do it very differently, and the right choice depends on your infrastructure, your audience, and your tolerance for dropped frames.
What is RTMP?
RTMP (Real-Time Messaging Protocol) was developed by Macromedia (later Adobe) in the mid-2000s. It became the standard for Flash-based streaming and remained the de facto ingest protocol for platforms like YouTube Live, Twitch, and Facebook Live.
Key characteristics:
- TCP-based: reliable delivery, but vulnerable to head-of-line blocking
- Low latency: typically 1-3 seconds in optimal conditions
- Widely supported: virtually every encoder and platform speaks RTMP
- No built-in encryption: relies on RTMPS (TLS wrapper) for security
RTMP works great on stable, low-latency networks. It’s the “just works” protocol.
What is SRT?
SRT (Secure Reliable Transport) was developed by Haivision and open-sourced in 2017. It was designed from the ground up for unreliable networks: cellular bonding, satellite uplinks, and public internet connections.
Key characteristics:
- UDP-based: avoids TCP head-of-line blocking
- ARQ error recovery: retransmits only lost packets, not the entire stream
- AES-128/256 encryption: built-in, not bolted on
- Adjustable latency: you choose the buffer size based on network conditions
- Bandwidth overhead reporting: real-time metrics on packet loss, jitter, RTT
SRT was built for the real world, where networks drop packets and bandwidth fluctuates.
Head-to-Head Comparison
| Feature | RTMP | SRT |
|---|---|---|
| Transport | TCP | UDP |
| Encryption | RTMPS (TLS) | AES-128/256 native |
| Error Recovery | TCP retransmit (all) | ARQ (selective) |
| Latency | 1-3s | Configurable (20ms-8s) |
| Firewall Friendly | Yes (port 1935) | Needs UDP ports |
| Packet Loss Tolerance | Poor | Excellent (up to 30%) |
| Bonding Support | No | Yes (SRTLA) |
| Adoption | Universal | Growing fast |
When to Use RTMP
RTMP is still the right choice when:
- You’re ingesting to major platforms: YouTube, Twitch, and Facebook still prefer RTMP ingest
- Your network is stable and local: LAN or dedicated circuits with <1ms jitter
- Encoder compatibility matters: some older hardware only speaks RTMP
- You need maximum simplicity: RTMP is “set the URL and go”
When to Use SRT
SRT is the better choice when:
- You’re sending over the public internet: SRT handles packet loss gracefully
- You need encryption: AES-256 is built in, no extra infrastructure needed
- You’re doing remote production: SRTLA bonding lets you aggregate multiple cellular connections
- You want real-time diagnostics: SRT exposes loss rate, RTT, jitter, and bandwidth metrics
- Reliability is non-negotiable: SRT’s ARQ ensures clean delivery even on lossy networks
The Vajra Cast Approach
With Vajra Cast, you don’t have to choose. Our gateway accepts both protocols simultaneously and converts between them in real-time:
- Receive RTMP from legacy encoders, output SRT to your production network
- Receive SRT from remote cameras, output RTMP to social platforms
- Mix and match inputs and outputs across protocols
Plus, with automatic failover, if your primary SRT feed drops, Vajra Cast switches to the backup RTMP input in under 50ms. No manual intervention.
Bottom Line
Use SRT whenever possible. It’s the modern choice: encrypted, resilient, and observable.
Use RTMP when platform compatibility or legacy equipment forces your hand.
Use both when you need maximum flexibility, which is exactly what a protocol-agnostic gateway like Vajra Cast gives you.