Model detail
Rerank v4.0 Fast
Cohere's AI search foundation model for enhancing the relevance of information surfaced within search and RAG systems. Features a 32K context window, multilingual support across 100+ languages, no data pre-processing required, and high performance with lowest latency.
Model specs
- Model ID
-
rerank-v4.0-fast
- Context length
- 32K
- Max output
- –
- I/O modalities
- –
- Released
- 2026-04
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API endpoints
One MixRoute gateway, OpenAI-compatible
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OpenAI-compatible
/v1/chat/completionsPOST
03
Tiered pricing
Unit: /1M Tokens
| Tier |
|---|
| base |
05
Selection summary
Quickly judge whether it fits your workload
What is this model good for?
Reranking
Rerank v4.0 Fast is Cohere's reranking model for second-stage ranking of retrieved passages. It accepts text input and returns ranked results. Rerank one query with your own documents before you wire it in.
What should you check before using it?
32,768 tokens across query and documents
Rerank v4.0 Fast handles up to 32,768 tokens across the query and its documents in one request. Size your query and document set against that window.
Why use it through MixRoute?
One MixRoute key reaches Rerank v4.0 Fast
One MixRoute key covers rerank-v4.0-fast, on the same account as the rest of the catalog. MixRoute supports calling Rerank v4.0 Fast through its OpenAI-compatible endpoint; point your client at https://api.mixroute.ai/v1 with the model ID rerank-v4.0-fast and re-run your integration tests.
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FAQ
Before switching production traffic to Rerank v4.0 Fast, run a pilot on a representative slice of your traffic and check output quality, latency at peak concurrency, and cost per request. Verify the error and retry behaviour, and confirm the request limits you depend on match your plan.
More from Cohere
All Cohere modelsOne endpoint, a testable decision
Test this model and alternate routes with the same request format
Start from a real workload, then let quality, total cost, and failure conditions decide whether to send production traffic.