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Personal RAG - Private Semantic Search

AI & LLM Tools

What is Personal RAG - Private Semantic Search?

Personal RAG is a private, offline-capable semantic search engine that runs entirely in your browser. It indexes your documents and lets you query them using natural language — finding meaning rather than just matching keywords. Under the hood, it chunks documents, generates embeddings using the all-MiniLM-L12-v2 model via ONNX Runtime Web, and stores the vector index in the browser's Origin Private File System (OPFS). Your documents never leave your device, making this ideal for private research, personal knowledge bases, or sensitive files you don't want in the cloud.

How it works

On upload, documents are parsed in a Web Worker (PDF via pdf.js, DOCX via mammoth, text files directly, images via Tesseract OCR). They are chunked using a recursive splitter and each chunk is embedded using all-MiniLM-L12-v2 running via ONNX Runtime Web. The vector index is stored in OPFS. On query, your search phrase is embedded and cosine similarity is computed against all chunks. Top-k results are returned with their relevance scores.

Features & Benefits

  • Files never leave your device - all processing happens in the browser via WebAssembly
  • Index persists across sessions using OPFS (browser's private file system)
  • Supports PDF, DOCX, images (OCR), and plain text files
  • True semantic search using neural embeddings - finds meaning, not just keywords

Frequently Asked Questions

Is my data private?

Yes. Everything runs locally in your browser. Files are parsed in a Web Worker, embeddings are computed on-device, and the index is stored in your browser's Origin Private File System (OPFS) - accessible only by this site.

What file types are supported?

Plain text (.txt, .md, code files), PDF, DOCX, and images (PNG, JPG, etc. via OCR). Images require an initial OCR pass before embedding.

Will my index survive a page refresh?

Yes. The vector index is stored in OPFS and persists across sessions. You can clear it at any time from the Index Manager.

How big can my document collection be?

Up to 500 files per ingestion batch. The index size is limited by your browser's OPFS quota (typically ~10% of available disk space).

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