mxbai-rerank-v3.1-listwise

· Mixedbread ·

2 min read Original article ↗

mxbai-rerank-v3.1-listwise is now available as the default reranker.

It delivers gpt-5.6-sol-level ranking quality with substantially improved latency over mxbai-rerank-v3-listwise. It is excellent at complex tasks like recency-aware ranking, source-priority resolution, and multi-step composite instructions, compared with leading LLMs and pointwise rerankers.

Quality versus latency on ViDoRe v3: mxbai-rerank-v3.1-listwise reaches gpt-5.6-sol quality at roughly 61 times lower latency, while Cohere and the GPT-5.6 rerankers are slower.

Sampled queries per ViDoRe subset with Mixedbread base search (Wholembed v3) as first stage.

Show the data behind this chart
Reranker on top of the first stageNDCG@10 (ViDoRe v3, sampled queries)Latency per query
First stage only (Wholembed v3)0.620.10 s
+ cohere rerank-4-pro0.661.6 s
+ gpt-5.6-terra (high)0.7036 s
+ gpt-5.6-sol (high)0.7040 s
+ gpt-5.6-luna (high)0.7073 s
+ mxbai-rerank-v3.1-listwise0.710.65 s

Higher NDCG@10 and lower latency are better. Values are decoded from the chart's plotted positions (NDCG@10 to ±0.005, latency to about ±5%); the 61× figure is gpt-5.6-sol's latency divided by v3.1's.

Unlike pointwise rerankers measuring the relevance of individual documents, our listwise v3 reads the whole candidate set for better reasoning at the cost of higher ranking latency.

Now, by rewriting its underlying inference engine, v3.1 reranks faster across every input size, matching pointwise rerankers. In production, the speedup ranges from ~25% on typical queries to ~54% on long-tail inputs (64–128k tokens).

Median reranking latency by input size: mxbai-rerank-v3.1-listwise is faster than v3 at every input size.
Show the data behind this chart
Input size (tokens)v3 median latencyv3.1 median latencySpeedup
< 8k159 ms119 ms25%
8–16k258 ms188 ms27%
16–32k380 ms243 ms36%
32–64k611 ms348 ms43%

Median reranking latency in production; lower is better. Values are decoded from the chart's plotted positions (±3 ms). The ~54% speedup quoted in the text is for 64–128k-token inputs, which the chart does not show.

For better threshold cutoffs, we also changed v3.1 to return content-dependent relevance scores instead of a fixed rank-based ladder in v3.

mxbai-rerank-v3.1-listwise is available today through Mixedbread Search:

from mixedbread import Mixedbread

client = Mixedbread()

results = client.stores.search(
    store_identifiers=["my-store"],
    query="when is my flight to London? The most recent valid booking wins",
    search_options={
      "rerank": {
          "model": "mixedbread-ai/mxbai-rerank-v3.1-listwise",
      }
    },
)