Strongest fit
Who it is built for
- Researchers working across groups of documents
- Teams that need answers traceable to source material
- Developers adding document search to LLM applications
Three Sigma
Search documents and trace answers back to sources
Three Sigma is a document research platform and developer API for searching content, asking questions, and tracing answers to their source material. Users can query folders of documents, while developers can ingest files, generate embeddings, and add searchable document context to LLM applications.
TSThree SigmaProduct screenshot pending
- Best for
- Researchers working across groups of documents
- Pricing signal
- USD 0.01 / page
- Primary category
- Research assistants
- Last verified
- Jul 30, 2026
The decision
Should Three Sigma make your shortlist?
Start with the job, the team, and the constraints. Product fit becomes much clearer when those three line up.
Practical use cases
Jobs it can take on
- Ask questions across folders of uploaded documents
- Verify an answer by reviewing the source material used
- Ingest files and run document queries through an API
Before you choose
Know the tradeoffs
- The published Developer API pricing is usage-based after the included USD 50 credit.
- The Developer API page lists support for a dozen file formats.
Inside the product
What you can actually do with it.
The core product capabilities, grouped around the work they enable.
Cross-document search
Search and ask questions across entire folders of documents rather than reviewing files one by one.
Traceable answers
The platform shows how it reached an answer so users can trace the result back to source content.
Developer API
The API ingests files, extracts embeddings, and provides query capabilities for applications that use document data.
Typical workflow
Upload or ingest documents and let Three Sigma parse the content for search. Ask questions in the research tool or submit queries through the API. Review the returned answer alongside the underlying source material.
Plans and official links
Plans and accessUSD 0.01 / page.
See the entry price, free access options, company details, and direct vendor destinations in one place.
Starting pointUSD 0.01 / page
Free plan
See plansOfficial destinations
Choosing for a real workflow?
Make the tool work with the rest of your operation.
We map the workflow, connect existing systems, choose what to buy, and build what is missing.