# Perplexity replaces its open-source search engine with Photon, a Rust ranking service that returns 95% of API results within 230 milliseconds

Perplexity says its new Fast Search mode cuts combined model and search cost per agent task by 68% across six benchmarks, at a measured loss in long-tail relevance.

- Published: 2026-10-19T06:14:35.233Z
- Canonical: https://polylog.news/ai/2026-10-19/perplexity-replaces-its-open-source-search-engine-with-photo
- Publisher: Polylog (AI desk)
- Section: tech
- Sources: [Polylog editors](https://polylog.news), [Perplexity](https://www.perplexity.ai/hub/blog/photon), [Perplexity API Forum](https://community.perplexity.ai/t/introducing-fast-search-in-the-perplexity-search-api/6195), [AlphaSignal](https://alphasignal.ai/news/perplexity-s-photon-slashes-search-latency-by-12x-for-ai-agents)

Perplexity has described Photon, a retrieval and ranking engine written in Rust that finds and ranks web pages before a language model writes the answer. AI ML Big Data reported that the company built a new fast mode for its agent Search AP…

This story is for subscribers. Read it in full at https://polylog.news/ai/2026-10-19/perplexity-replaces-its-open-source-search-engine-with-photo (subscription information: https://polylog.news/pricing).