Request cascades through models until one responds successfully.
Fallback Chain
GPT-4oOpenAI
⏱ 820ms💰 $5/1kHEALTHY
PRIMARY
↓ fallback
Claude SonnetAnthropic
⏱ 680ms💰 $3/1kHEALTHY
↓ fallback
Llama 3.1 70BSelf-hosted
⏱ 1100ms💰 $0.9/1kHEALTHY
↓ fallback
Llama 3.1 8BSelf-hosted
⏱ 250ms💰 $0.1/1kHEALTHY
Inject Failure
GPT-4o
Claude Sonnet
Llama 3.1 70B
Llama 3.1 8B
Retry Attempts2
13
Backoff Multiplier2×
1×4×
Status Legend
healthy
degraded
down
Backoff Formula
delay = base × mult^(n-1)
Attempt 2: 1000ms delay
Model Fallback and Retry - Interactive Visualization
Production LLM systems must handle provider outages, rate limits, and timeouts gracefully. A model fallback chain routes requests through a prioritized list of models - GPT-4o first, then Claude Sonnet, then a self-hosted Llama - with exponential backoff between retries. This pattern ensures high availability without sacrificing quality when the primary provider is unavailable.
Fallback chain: configure primary, secondary, and tertiary model providers in order
Failure injection: simulate rate limits, timeouts, and API errors at each provider
Exponential backoff: watch retry delays grow - 1s, 2s, 4s - before cascading to the next model
Latency impact: see how fallback adds end-to-end latency and when it is worth the tradeoff
Part of the EngineersOfAI Interactive 3D - free interactive visualizations covering every major concept in machine learning and AI engineering. Hover any element for a plain-English explanation. No code required.