Why your JSON never leaves the browser
The concrete architecture behind the local-processing claim.
August 25, 2026 · 5 minute readThe network delivers code, not documents
jsontools.me downloads an application shell, a worker, and a WebAssembly module. When you paste or open a document, its UTF-8 bytes are transferred directly to that worker. There is no payload API in the product architecture.
The worker owns the document
json-buf parses the bytes in WebAssembly and returns an opaque numeric handle. Subsequent format, query, diff, schema, and analysis operations reference that handle instead of resending or reparsing the source.
Analytics has a hard boundary
Product events can contain a tool name, input-size bucket, duration bucket, and runtime. Fields such as payload, path, query, value, input, or output are rejected by the event schema.