AI PDF Parsing in 2026: MinerU, Marker and Docling Compared (Real Stars)
AI PDF parsing is the foundation of every RAG system. We compared MinerU, Marker, Docling and Unstructured with verified GitHub stars, accuracy notes and use cases.
💡 What You Will Learn
AI PDF parsing is the foundation of every RAG system. We compared MinerU, Marker, Docling and Unstructured with verified GitHub stars, accuracy notes and use cases.
Garbage in, garbage out applies to RAG more than anywhere else. If your PDF parser mangles tables and drops formulas, no retrieval pipeline can save you. AI PDF parsing is where RAG quality is actually decided.
MinerU - The Heavy Lifter
MinerU (opendatalab/MinerU, 76,942 stars) is the current leader for hard documents: scanned PDFs, multi-column papers, formulas, and tables. It runs OCR when needed and outputs markdown or JSON with layout preserved. If your documents are messy scans, start here.
Docling (docling-project/docling, 64,320 stars) from IBM research excels at document structure - headings, tables, reading order - and exports to HTML, markdown, and JSON. Marker (datalab-to/marker, 38,453 stars) focuses on fast, accurate PDF-to-markdown conversion. Unstructured (15,268 stars) is a framework covering 25+ file types.
Comparison
| Tool | Strengths | Stars |
|---|---|---|
| MinerU | Complex layouts, formulas, OCR | 76,942 |
| Docling | Structure-aware conversion | 64,320 |
| Marker | PDF to markdown speed | 38,453 |
| Unstructured | 25+ formats pipeline | 15,268 |
FAQ
Q: Which parser is most accurate for tables?
A: MinerU and Docling both handle complex tables well; test both on your own documents before committing.
Q: Do these need a GPU?
A: All can run on CPU, but GPU speeds up OCR-heavy documents 5-10x.
