MoQ vs WebRTC

This page compares MoQ with WebRTC, the dominant protocol for real-time browser communication and video conferencing.

What is WebRTC?

WebRTC (Web Real-Time Communication) is a browser API and protocol suite for peer-to-peer audio, video, and data communication. It powers:

Video conferencing (Zoom, Google Meet, Teams)
VoIP applications
Peer-to-peer file sharing
Live streaming (some implementations)

WebRTC was designed for bidirectional, low-latency communication between peers.

Comparison Table

Feature	WebRTC	MoQ
Primary Use	Conferencing	Live streaming
Connection Model	Peer-to-peer / SFU	Relay-based
Browser Support	Excellent	WebTransport required
Latency	<100ms typical	<100ms - 1s
Scale	10s-100s per session	Millions
Media Control	Browser-controlled	App-controlled
NAT Traversal	STUN/TURN/ICE	WebTransport (HTTP/3)
Encryption	DTLS-SRTP	QUIC TLS 1.3
Codec Negotiation	SDP	Application-level

Architecture Differences

WebRTC Architecture

text

┌────────┐     ┌────────┐
│ Peer A │◄───►│ Peer B │  (Peer-to-Peer)
└────────┘     └────────┘

┌────────┐     ┌─────┐     ┌────────┐
│ Peer A │◄───►│ SFU │◄───►│ Peer B │  (With SFU)
└────────┘     └─────┘     └────────┘
                 ↕
              ┌────────┐
              │ Peer C │
              └────────┘

P2P: Direct connection between peers
SFU: Selective Forwarding Unit routes media between many peers
MCU: Mixing server (less common now)

MoQ Architecture

text

┌───────────┐     ┌───────┐     ┌────────────┐
│ Publisher │────►│ Relay │────►│ Subscriber │
└───────────┘     └───────┘     └────────────┘
                      │
                      ▼
                 ┌───────┐
                 │ Relay │  (CDN mesh)
                 └───────┘
                      │
                      ▼
               ┌────────────┐
               │ Subscriber │
               └────────────┘

Publisher-subscriber model
Relays form CDN-like mesh
Clear separation of roles

Key Differences

1. Connection Model

WebRTC: Designed for bidirectional peer communication

Each participant is both sender and receiver
Connection establishment is complex (ICE, STUN, TURN)
SFU needed for more than a few participants

MoQ: Designed for broadcast/multicast

Clear publisher and subscriber roles
Simple connection (WebTransport over HTTP/3)
Natural fan-out via relays

2. Media Pipeline Control

WebRTC: Browser controls the media pipeline

Browser decides codec, bitrate, resolution
Limited application control
Simulcast for multi-quality (complex)
SVC support varies

MoQ: Application controls the media pipeline

App decides codec, bitrate, resolution via WebCodecs
Full control over encoding/decoding
Multiple tracks for different qualities
Any codec WebCodecs supports

3. Scalability

WebRTC:

P2P: 2-4 participants max
SFU: 10-100 participants typical
Each new viewer requires SFU resources
Complex mesh for large meetings

MoQ:

Designed for 1-to-millions
Relay fan-out is efficient
CDN-like scaling patterns
Resource usage scales with publishers, not viewers

4. Latency Characteristics

WebRTC:

Optimized for <100ms latency
Jitter buffers typically 50-150ms
Aggressive packet loss concealment
Designed for real-time conversation

MoQ:

Configurable latency
Can be <100ms for real-time
Can buffer more for better quality
Prioritization over reliability

5. NAT Traversal

WebRTC:

Complex ICE negotiation
STUN servers for discovery
TURN servers for relay fallback
Connection setup takes seconds

MoQ:

WebTransport uses HTTP/3
Works through most firewalls
No special traversal needed
Connection setup is fast

6. Browser Support

WebRTC:

All major browsers
Mature and stable
getUserMedia API for capture
RTCPeerConnection API

MoQ:

Requires WebTransport (Chrome, Edge)
Firefox/Safari: experimental or coming
WebCodecs for encoding/decoding
Newer APIs, less mature

Use Case Analysis

Video Conferencing (2-10 people)

WebRTC is better:

Designed for this use case
Bidirectional is natural
Low latency by default
Mature ecosystem

MoQ approach:

Each participant publishes
Each participant subscribes to others
Works, but more complex for small groups

Large Meeting (10-1000 people)

WebRTC with SFU:

SFU routes media between participants
Works well for known participant sets
Resource-intensive for many active speakers

MoQ:

Natural fit for few speakers, many viewers
Efficient fan-out
Viewers can subscribe to speakers they want

Live Streaming (1 to many)

WebRTC:

Not designed for this
SFU becomes bottleneck
Often combined with HLS fallback
Complex infrastructure

MoQ is better:

Designed for broadcast
Natural relay fan-out
CDN-like scaling
Simpler architecture

Interactive Live Streaming

WebRTC:

Good for bringing viewers "on stage"
Complex when mixing models
Often hybrid WebRTC + HLS

MoQ:

All participants use same protocol
Easy to promote viewer to speaker
Data channels for chat built-in

Technical Comparison

Codec Handling

WebRTC:

javascript

// Browser negotiates codecs
const pc = new RTCPeerConnection();
// Codecs determined during SDP exchange
// Limited control

MoQ with WebCodecs:

javascript

// Full control over encoding
const encoder = new VideoEncoder({
    output: (chunk) => sendToMoQ(chunk),
});
encoder.configure({
    codec: 'avc1.42001f',
    width: 1280,
    height: 720,
    bitrate: 2_500_000,
});

Connection Setup

WebRTC:

Create offer
ICE candidate gathering
STUN/TURN queries
Answer exchange
ICE connectivity checks
DTLS handshake
Media flow begins

MoQ:

WebTransport connect (HTTP/3)
MoQ session established
Announce/Subscribe
Media flow begins

Error Recovery

WebRTC:

FEC (Forward Error Correction)
NACK-based retransmissions
PLI (Picture Loss Indication)
Concealment at decoder

MoQ:

QUIC reliability per-stream
Prioritization (drop old, send new)
Application-level recovery
Frame-level control

When to Use What

Use WebRTC when:

Building video conferencing
All participants send and receive
Group size is small (<100)
You need mature browser support
Lowest latency is critical

Use MoQ when:

Building live streaming
Clear publisher/viewer roles
Scale to thousands or millions
You want media pipeline control
End-to-end delivery (no HLS fallback)

Consider Both when:

Interactive live streaming
Webinars with Q&A
Hybrid use cases

Migration & Interop

Using Both Protocols

Many applications can benefit from both:

Conferencing:
  Host ↔ WebRTC ↔ Guest (small group, bidirectional)

Broadcasting:
  Host → MoQ → Relay → Viewers (large audience, unidirectional)

Promotion:
  Viewer → WebRTC → Host (bring on stage)

MoQ for WebRTC-like Use Cases

MoQ can implement conferencing patterns:

Each participant publishes their streams
Each participant subscribes to others
Relay handles routing
Works, but different trade-offs

Summary

Use Case	Winner
1-on-1 calls	WebRTC
Small meetings	WebRTC
Large meetings	MoQ or hybrid
Live streaming	MoQ
Interactive streaming	MoQ
Broadcast to millions	MoQ

WebRTC excels at real-time bidirectional communication between small groups.

MoQ excels at scalable live delivery from publishers to viewers.

Next Steps

Compare with contribution protocols (RTMP/SRT)
Compare with distribution protocols (HLS/DASH)
Read the Protocol specification
Try the Quick Start

Layers

Standards

Use Cases

MoQ vs WebRTC

What is WebRTC?

Comparison Table

Architecture Differences

WebRTC Architecture

MoQ Architecture

Key Differences

1. Connection Model

2. Media Pipeline Control

3. Scalability

4. Latency Characteristics

5. NAT Traversal

6. Browser Support

Use Case Analysis

Video Conferencing (2-10 people)

Large Meeting (10-1000 people)

Live Streaming (1 to many)

Interactive Live Streaming

Technical Comparison

Codec Handling

Connection Setup

Error Recovery

When to Use What

Use WebRTC when:

Use MoQ when:

Consider Both when:

Migration & Interop

Using Both Protocols

MoQ for WebRTC-like Use Cases

Summary

Next Steps

MoQ vs WebRTC ​

What is WebRTC? ​

Comparison Table ​

Architecture Differences ​

WebRTC Architecture ​

MoQ Architecture ​

Key Differences ​

1. Connection Model ​

2. Media Pipeline Control ​

3. Scalability ​

4. Latency Characteristics ​

5. NAT Traversal ​

6. Browser Support ​

Use Case Analysis ​

Video Conferencing (2-10 people) ​

Large Meeting (10-1000 people) ​

Live Streaming (1 to many) ​

Interactive Live Streaming ​

Technical Comparison ​

Codec Handling ​

Connection Setup ​

Error Recovery ​

When to Use What ​

Use WebRTC when: ​

Use MoQ when: ​

Consider Both when: ​

Migration & Interop ​

Using Both Protocols ​

MoQ for WebRTC-like Use Cases ​

Summary ​

Next Steps ​

MoQ vs WebRTC

What is WebRTC?

Comparison Table

Architecture Differences

WebRTC Architecture

MoQ Architecture

Key Differences

1. Connection Model

2. Media Pipeline Control

3. Scalability

4. Latency Characteristics

5. NAT Traversal

6. Browser Support

Use Case Analysis

Video Conferencing (2-10 people)

Large Meeting (10-1000 people)

Live Streaming (1 to many)

Interactive Live Streaming

Technical Comparison

Codec Handling

Connection Setup

Error Recovery

When to Use What

Use WebRTC when:

Use MoQ when:

Consider Both when:

Migration & Interop

Using Both Protocols

MoQ for WebRTC-like Use Cases

Summary

Next Steps