Voyage rerank-3

Hosted API · Voyage AI ·

Hosted APIPer token32K context

Voyage AI’s current rerankers are rerank-3, which Voyage call their highest-accuracy model and recommend for most applications, and rerank-3-lite, tuned for latency. Both accept 32,000 tokens of query plus document, and both are billed per token with 200 million free tokens per account. The previous rerank-2.5 generation is still served at the same price — and it’s the one Voyage document for natural-language instructions and the Batch API.

Available models

ModelContextNotes
rerank-332,000 tokensHighest accuracy; Voyage’s recommendation for most applications
rerank-3-lite32,000 tokensFast and cost-effective, for latency-sensitive use
rerank-2.5 / rerank-2.5-lite32,000 tokensOlder; instruction-following and multilingual, per Voyage’s docs
rerank-2 / rerank-2-lite16,000 / 8,000 tokensOlder

Per request the query can be up to 8,000 tokens, the query plus any one document up to 32,000, with up to 1,000 documents and 600K tokens in total — counting the query once per document.

Instructions — a line such as “prefer passages that cite a statute” added to the query — reshape relevance without training data. Voyage introduced them with rerank-2.5, and their rerank-3 announcement says the Rerank 3 series keeps them: on the MAIR instruction-following benchmark, rerank-3 scores on par with rerank-2.5 in Voyage’s own test.

What changed in rerank-3

Voyage released rerank-3 and rerank-3-lite on 30 September 2026 as a drop-in upgrade to the 2.5 series: same API, context length, instruction support and price, and relevance scores calibrated to match the 2.5 models, so thresholds you tuned on 2.5 should still hold. rerank-2.5 remains available.

These are Voyage’s own evaluations; no independent benchmark covers rerank-3 yet. Source: Voyage’s announcement. Voyage also publish each model’s tokenizer — no weights — on Hugging Face, which you can use to count tokens locally before you’re billed for them.

Pricing

ModelPer 1M tokensFree tokens
rerank-3$0.05200 million
rerank-3-lite$0.02200 million
rerank-2.5 / -lite$0.05 / $0.02None
Batch API33% offrerank-2.5 and -lite; free tokens don’t apply

Billed tokens = query tokens × number of documents + all document tokens. At list price, 100 documents of 500 tokens each (query included) cost $0.0025 on rerank-3 — Voyage’s own example, and exactly the price of one Cohere Rerank 4 Pro search. Voyage’s pricing page still says in one sentence that rerank-2.5 includes free tokens, while its price table lists rerank-2.5 under older models with none; we follow the table. Prices from docs.voyageai.com/docs/pricing, verified 1 October 2026 and re-checked daily by this site’s source check.

Quick start

Python

pip install voyageai
import voyageai

vo = voyageai.Client(api_key="YOUR_API_KEY")

query = "How do I add reranking to my RAG pipeline?"
documents = [
    "Rerankers score each query-passage pair with a cross-encoder.",
    "BM25 is a classical keyword-based retrieval method.",
    "London is the capital of the United Kingdom.",
    "Two-stage retrieval: retrieve 50 candidates, rerank to top 5.",
]

result = vo.rerank(
    query=query,
    documents=documents,
    model="rerank-3",
    top_k=3,
)

for r in result.results:
    print(f"{r.relevance_score:.4f}  {documents[r.index][:80]}")

REST (curl)

curl https://api.voyageai.com/v1/rerank \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "rerank-3",
    "query": "How do I add reranking to my RAG pipeline?",
    "documents": ["Rerankers score...", "BM25 is..."],
    "top_k": 3
  }'

In a RAG pipeline

import voyageai

vo = voyageai.Client(api_key="YOUR_API_KEY")

def rag_answer(query: str, vector_db, llm) -> str:
    # Stage 1: retrieve wide
    candidates = vector_db.search(query, top_k=50)
    # Stage 2: rerank tight
    result = vo.rerank(query=query, documents=candidates, model="rerank-3", top_k=5)
    top5 = [candidates[r.index] for r in result.results]
    # Stage 3: generate
    return llm.complete(f"Context:\n" + "\n\n".join(top5) + f"\n\nQ: {query}")

Pros and cons

Pros

  • rerank-3: Voyage’s highest-accuracy reranker, 32K tokens per query–document pair
  • Billed for exactly the tokens you send — cheap for short passages
  • 200 million free tokens per account on rerank-3 and -lite
  • Same API key and client as Voyage embeddings
  • Python and TypeScript libraries, plus REST

Cons

  • No open weights; private deployment goes through the AWS or Azure marketplace
  • The Batch discount is documented only for the older rerank-2.5
  • No published BEIR average — comparisons rest on Voyage’s own evaluations
  • Smaller community than Cohere or bge

See reranking in action

Our demo runs a cross-encoder in your browser — no API key, no cost, same reranking logic.

Open the demo →

Other models