jq vs jsonfmt.dev

jq is a free command-line processor for selecting and transforming JSON data. A jq filter takes an input and produces output; filters can be combined to access nested attributes, construct objects, gather results into arrays, or make other transformations. It reads whitespace-separated JSON values and writes serialized results separated by whitespace. Each expression runs on each input value and may produce zero or more outputs. For very large inputs, the --stream option parses incrementally. Output options include compact, raw, ASCII, sorted-key, and colored forms. Written in portable C, jq has no runtime dependencies, and a standalone binary can be copied to another machine of the same type. Standalone executables are available for Linux, macOS, and Windows, with packages listed for Linux distributions and package managers including Homebrew, MacPorts, winget, Scoop, and Chocolatey. A Docker image is also available. Release binaries have SHA-256 checksums, and signed release artifacts use jq release keys. The code is licensed under MIT; the documentation uses CC-BY-3.0.

jsonfmt.dev is a web-based JSON formatter, beautifier and validator, with an HTTPS API for JSON processing. The formatter offers 2-space, 4-space or tab indentation, optional key sorting and depth control. It validates JSON against RFC 8259 and reports line and column errors. Other tools can repair common malformed JSON, compare two documents and convert formats including YAML, CSV, XML, TypeScript, SQL, GraphQL and Protobuf. The toolkit also includes a JWT decoder, JSON Schema validator, JSONPath evaluator and JSONL tools. The maker says the core browser tool handles JSON locally without sending its contents to the server, and continues to work offline after loading; it can also be installed as a Progressive Web App. API options include anonymous access limited to 10 requests per minute, a free API key tier with 100 requests per minute and 1,000 per month, and Pro API at $9, paid once for 1,000 requests per minute and 50,000 per month. Share links encode JSON in the URL fragment, and anyone with the link can access its contents.