WhatsApp Business API rate limits
The default rate limit is 80 messages per second per phone number. For accounts with high quality history and proven volumes, Meta can approve higher rate limits.
The rate limit applies per phone number, not per WABA account. If you need to send 200 messages per second, distribute the load across three numbers at 80 msg/s each.
Queue architecture for high volumes
For high volumes, the optimal architecture uses a message queue as a buffer: your system produces messages at maximum speed, the queue accumulates them, and the consumer sends them respecting the rate limit.
Monitor queue depth: if it grows constantly, production speed exceeds consumption speed. Add WhatsApp numbers, increase rate limit, or reduce production speed.
Distribution across multiple numbers
With multiple WhatsApp numbers in your WABA, distribute the load via round-robin or load balancing. Chat API supports managing multiple numbers in the same account, with separate metrics per number for quality monitoring.
Monitoring and alerting for high-volume systems
For high-volume production systems, monitor in real time: queue depth, consumption rate, 429 errors per minute, average latency from send to delivered webhook, and quality score per number.
