Lettria

Lettria converts unstructured data into structured knowledge to make AI systems more reliable and traceable. It parses documents automatically, generates production-grade ontologies from domain-specific knowledge, and reasons over complex relationships in linked documents and figures to give reliable answers. It runs on the web and through an API.

Lettria has no free tier. The Developer plan costs $0.01 per PCU and offers limited features with a max of 30 KB input size, while the Plus plan costs $19 per month and adds more graph and ontology building, email support and a limit of 5 graph builds per 30 days. The Enterprise plan is custom.

Toolio lists regulated industries seeking accuracy as the best fit for Lettria. The tool is built for compliance and traceability, and the reviewer credits it with 30%+ better accuracy compared to vector search methods. Fast-evolving or regulated domains with complex needs may require in-house experts for custom ontology engineering.

The reviewer's main reservation is that Lettria starts with a pilot program to scope its value, which can be lengthy. Complex domains need custom deployment with in-house experts, and the Enterprise plan is custom and likely more expensive than other options.

Lettria holds a Toolio score of 3.9 out of 5, given by Alex after real use on 5 Oct 2026. The reviewer credits it with turning complex documentation into usable AI through ontology-powered intelligence. It has been listed on Toolio since September 2024.