Best PDF Parsers for RAG Applications

Tool / Library	Strengths / Best For	Weaknesses / Limitations
Datalet (Marker)	Likely good for structured extraction, maybe layout awareness. Note: specific details depend on documentation.	May have limited community / maturity; possibly less flexible for unusual layouts.
llamaindex	Popular in the RAG / LLM community; good for embedding + indexing + pipelines. You can plug in different document loaders / parsers.	Parsing support depends on external libraries; handling really bad PDFs / scans may require additional modules / custom logic.
jina ai	Strong in search, embeddings, building vector indexes; likely has tools or connectors for document ingestion.	Might require configuration / customization for advanced table extraction or for scans / OCR.
Unstructured.io	Very strong in extracting structured info from complex documents; good tools for handling layout, splitting etc.	Might be more resource intensive; licensing / cost if using commercial or enterprise versions.
Vectorize.io	Good commercial options; probably optimized for speed / production usage.	May cost; may limit customization; handling odd edge cases might require fallback logic.
GroundX by eyelevel.ai	Likely focused, perhaps with custom models; possibly good quality for particular domains.	Might have less documentation / community; possibly domain-specific bias.
LangChain	Excellent orchestration framework; many existing document loaders that use PDF libraries + OCR; great for building full RAG pipelines.	LangChain itself is not a PDF extractor — quality depends on underlying extraction tool; for many edge cases you’ll need to extend/customize.
PyMuPDF (fitz)	Strong low-level library; very good for getting text, images, extracting metadata, positions. Fair speed.	Doesn’t do OCR out of the box; tables detection is minimal; complex layout rebuilding / semantic understanding has to be built on top.
pdf-js	Good for browser / NodeJS usage; rendering, interacting with PDFs in client side or server side. Can extract text.	Limited in table detection, forms, OCR; not ideal if you need heavy layout or image-based extraction.