QDev — QDev

QDev is a fast, local-first viewer for JSON, YAML, and TOON, built to open and search gigabyte-scale files in seconds without freezing your browser. Explore structure in a tree or an interactive graph, jump anywhere with cmd+K search, and query with jq, all on your device.

WHAT YOU CAN DO
• Open huge files: multi-gigabyte JSON, YAML, and TOON load with a progress bar and stay responsive.
• Search instantly: cmd+K fuzzy search across keys and values, even in massive documents.
• See your data two ways: a collapsible tree view and an interactive node graph for exploring nested structures and relationships.
• Infer a schema: generate a JSON Schema from any document in one click.
• Query with jq: run jq expressions locally (compiled to WebAssembly) with instant results, plus a built-in SQL view over arrays.
• Ask in plain English: optional AI turns a natural-language question into a jq query that then runs locally against your data.

PRIVATE BY DESIGN
Opening files, searching, schema inference, the graph, and jq all run entirely in your browser, so nothing is uploaded. The optional hosted AI mode sends only an inferred schema and your question (values are masked and never leave your device); on-device AI options send nothing at all.

Free to use, with no account when using local AI models.