Research2026-09-09

Perplexity released Q2D-Web, a private benchmark with a public leaderboard for search retrieval. It measures how well embedding models find candidate documents from a large web corpus. The corpus holds about 190 million pages and the query set 69,721 agent-rewritten queries in ten languages. Queries come from nine months of production search traffic, filtered for personal information. Relevance is labelled three ways: agent citations, production web rankings, and added language-model judgments. No single model leads on all three label sets. Perplexity's own pplx-embed-v1-4b scores highest on two of them, and Nemotron-3-Embed-8B on citations. Perplexity notes its models may gain an advantage because the data comes from its own traffic. A smaller sampled corpus cuts evaluation cost to about a third while preserving model ranking. Anyone can submit a public Hugging Face model for evaluation.

What changed

The closest public comparison, MS MARCO Web Search, had 100.9 million documents, 9,374 test queries and one click-derived label per query.

What it unlocks

Comparing publicly released embedding models for first-stage web retrieval on a large corpus with three separate relevance-label sets.

  • 190M documents, 69,721 queries
  • 99.6 positive judgments per query
  • pplx-embed-v1-4b: 69.11 Combined Recall@1000
  • RRF subcorpus uses 31.7% of corpus

What you need to act on it

  • a publicly available, non-gated Hugging Face model
  • loads via standard transformers or sentence-transformers
  • submission through Perplexity's evaluation request form

Send this to someone who needs it

Shares the story and its sources. Nothing about you.

What does this mean for your job?

This is the story as everyone gets it. Once a week we send you the version written for your role — what changed, why it matters for the work you actually do, and one thing to try. Free while we tune it.