OpenRouter is a service that gives developers one API for many AI models from different companies, with automatic fallback when a model or provider fails.
In plain words
Each AI company has its own API with its own format. OpenRouter sits in the middle: you send every request in one format, name the model you want, and it forwards the request to a provider that runs it. It can try backup models if the first one errors, is rate-limited or is down.
A quick example
Imagine an app that normally uses one model but keeps a second as backup. The developer lists both in the request. If the first is overloaded, OpenRouter quietly sends the request to the second, and the app is billed for whichever model actually answered.
Where you'll meet it
- Comparing or switching between many models with one integration.
- Apps that need a backup model for uptime.
Related
Sources
- DocsFrequently asked questions, OpenRouter · read 29 Sept 2026
- DocsModel fallbacks, OpenRouter · read 29 Sept 2026
- DocsAPI reference overview, OpenRouter · read 29 Sept 2026
Checked by WhatIsAI against the sources above · 29 Sept 2026. Spotted an error? Report it.