FOSS Face-Off: Open Source Perplexity Alternatives

In early August 2026, the U.S. Court of Appeals for the Ninth Circuit vacated a preliminary injunction Amazon had won against Perplexity AI over its agentic web browser. The dispute turned on whether an AI assistant that browses the web on your behalf qualifies as “accessing” a protected computer under the Computer Fraud and Abuse Act (CFAA). The panel found that, on the record before it, it was the user who accessed Amazon’s site — with Perplexity’s Assistant merely helping execute the user’s own actions — so Amazon was unlikely to succeed on the merits and an injunction was not warranted.

Whatever the eventual outcome, the case shines a light on a real tension: closed, cloud-hosted “answer engines” like Perplexity sit between you and the open web, and the terms that govern them are still being litigated. If you would rather own the search-and-answer pipeline yourself — no subscription, no proprietary browser agent, no third party deciding what “answering” means — the open-source ecosystem already covers every layer of it. Here are five of the strongest building blocks worth comparing.

SearXNG — The Private Metasearch Foundation

SearXNG (github.com/searxng/searxng) is a self-hosted metasearch engine that aggregates results from over 70 upstream services — Google, Bing, DuckDuckGo and Brave among them — and presents them through a single, clean interface without tracking, profiling or logging your searches. It is the actively maintained community fork of the retired searx project.

What makes SearXNG such a natural Perplexity alternative is that its JSON API lets other tools query it programmatically. That is the same plumbing a proprietary answer engine uses — but here the results server is yours, and it proxies your queries so no upstream service sees who you are. It is your own search core; you decide what sits on top of it.

Open WebUI — The AI Interface That Ties It Together

Open WebUI is an extensible, self-hosted AI platform that operates entirely offline. It connects to Ollama and any OpenAI-compatible API, and ships with a built-in Retrieval Augmented Generation (RAG) engine plus web search for RAG through dozens of providers — including, commonly, your own SearXNG instance. In other words, Open WebUI can do exactly what Perplexity’s Assistant promises: read your question, search the live web, retrieve relevant pages, and hand them to a local model to compose an answer with sources.

Because the whole chain — search, retrieval, model, and chat UI — runs on your own infrastructure, every answer comes from the open web and stays under your control. It is the closest open-source equivalent to a full Perplexity-style experience, and it is backed by a genuinely large open community.

Ollama — Run the Brain Locally

Ollama wraps model downloading, inference and management into a single CLI and API server, making it the easiest way to run LLMs on your own hardware. With support for thousands of models across the Llama, Mistral, Gemma, Phi and Qwen families, and an OpenAI-compatible API, it drops into existing tools with almost no friction.

For a Perplexity alternative, Ollama is the model layer: pair it with Open WebUI (which natively integrates Ollama) and a search backend, and the “answering” happens locally. No GPU is strictly required, and data never leaves your machine.

LocalAI — One API for the Whole Pipeline

LocalAI is a free, open-source, drop-in replacement for OpenAI’s API that runs entirely on your hardware. Beyond LLMs, it handles image generation, text-to-speech, speech-to-text (Whisper) and video models from a single endpoint — no GPU and no internet connection required.

Where Ollama focuses on chat models, LocalAI is the broader stack: one API that covers the text, voice and vision components of an answer engine. Its model gallery gives one-command downloads, and its CPU-only support means a Perplexity-style assistant can run on hardware you already own.

YaCy — The Decentralised Index

YaCy takes a different path entirely. Instead of a central search index, YaCy peers each run a network node that crawls and indexes the web, sharing results across the peer network — so search results come from a community-controlled index with no single point of failure or central censorship. It can also index your own intranet, files and documents.

If the Amazon-versus-Perplexity dispute is ultimately about who controls the browsing-and-search layer, YaCy is the most radical answer: a search index that no single company owns at all.

Fess — Enterprise-Grade Search on Your Own Terms

Fess is a powerful, easily deployable enterprise search server built in Java. It provides a full-featured web search interface out of the box, crawls websites, file shares, databases and documents, and offers admin tools for managing crawlers, users and search settings — a turnkey option for organisations that need deep, controlled search without heavy custom development.

Fess is the right choice when your “answers” need to come from your own documents and internal systems rather than the public web, with full access control over who can search what.

Which One Should You Run?

The right answer depends on how much of the Perplexity experience you want to replicate and where your data should live:

• Just private web search — start with SearXNG.
• A full answer-engine experience — combine Open WebUI with Ollama and a SearXNG backend.
• One API for every modality — LocalAI.
• No central index at all — YaCy.
• Internal, role-controlled search — Fess.

All of these are free and open source, and each one replaces a slice of the proprietary, cloud-hosted answer-engine stack with something you control. The court case will keep playing out; your options for running your own search and answers, in the meantime, are already here.

Looking for more tools like these? Browse the full directory of free and open source software.