Perplexity launched Alexandria on October 9, 2026: a free encyclopedia built by its agent system Computer, which will also keep maintaining it. In the announcement that day, CEO Aravind Srinivas gave unusually concrete numbers — 66,574 entries synthesized from 348,980 sources, at a cost of 2.5 million platform credits, roughly $25,000. The site is publicly accessible, and its pitch is simple: an encyclopedia where every sentence can be followed back to its sources.
Not another AI answer box
Alexandria is not the same thing as Perplexity's core Q&A product. Answers are one-off: close the page and they are gone. Encyclopedia entries are durable public pages that others can cite, link to, and revisit later to check whether the content changed. According to Srinivas, Computer scanned and synthesized the sources to write the entries, and Computer will keep maintaining them. The editorial desk has been replaced by a general-purpose work agent whose previous jobs were building dashboards, writing apps, and running research — this time it was assigned to compile an encyclopedia.
Every sentence can be clicked back to the original
Alexandria's homepage shows more than 2.57 million cited passages across the site. Claims in an entry carry their sources, so readers can follow a citation back to the original material and judge for themselves whether it holds up. That is exactly where it separates itself from ordinary model-generated text: the most common criticism of large models is that they state fabrications as if they were facts — hallucination, in the usual term. Making citations the skeleton of an entry at least gives anyone who wants to verify a path to follow. Of course, a clickable source is not automatically a reliable one; when source quality is uneven, the encyclopedia inherits that unevenness.
Do not treat it as a replacement for established encyclopedias yet
At 66,000 entries, Alexandria is small by encyclopedia standards, nowhere near the coverage of long-established references. It reads more like an experiment: when writing, citing, and revising are all handled by agents, the cost of building an encyclopedia drops to the $25,000 range, and competition shifts from headcount of editors to source selection and correction speed. Three things are worth watching next: who fixes an entry when it is wrong and how fast, whether citations genuinely support the claims in the text, and whether Computer's maintenance is scheduled inspection or waiting for reader reports. Perplexity recently open-sourced a multimodal embedding model; search and knowledge organization are becoming the line it pushes hardest.
