Local JSON Workbench

Format, beautify and validate JSON in your browser. Errors point to the exact line and column, and you can indent with 2 spaces, 4 spaces or a tab.

Check whether your JSON is valid. Syntax errors are highlighted with the exact line and column, plus a hint about the token that was expected.

Remove whitespace, indentation and line breaks to get compact single-line JSON — typically 15%–40% smaller. Optionally sort keys. Runs locally in your browser.

Render JSON as a collapsible tree with colour-coded types, search with ancestor expansion, JSONPath breadcrumbs, inline editing and windowed rendering for huge files.

Compare two JSON documents side by side. Additions, deletions and changes are colour-coded, and key or array order can be ignored.

Query JSON with JSONPath expressions, with a built-in syntax cheat sheet and one-click copy of each result.

Run jq 1.8 in your browser (WebAssembly build) — no install required. Edit the expression and see the result instantly.

Escape any text into a valid JSON string literal (newlines, tabs, quotes, backslashes) and unescape JSON string fragments back to their original text. Runs locally.

Recursively sort object keys in alphabetical order when you format or minify JSON. Arrays keep their order. Get deterministic output for diffs, snapshots and config baselines.

Open 10 MB+ JSON files in the browser. Parsing runs in a Web Worker and the tree renders only visible rows, so even a million nodes scroll smoothly. Text over 5 MB switches to read-only chunked view.

Describe the data you want in plain language and let an LLM generate valid JSON. Bring your own API key (BYOK): requests go straight from your browser to the model provider.

Paste a complex API response or config file and get a clear Markdown document describing its structure and fields. Bring your own API key (BYOK); requests go directly from your browser.

Feed a JSON skeleton or schema and let an LLM fill it with realistic mock data based on field names — names, emails, addresses, amounts, dates. Bring your own API key (BYOK).

A lightweight, browser-based HTTP client. Configure method, URL, headers and a JSON body, send the request and inspect status, timing, headers and the formatted JSON response.

Decode a JSON Web Token locally: view the Header and Payload as JSON and see standard claims such as iss, sub, exp and nbf with timestamps converted and expiry flagged. No signature verification.

Generate and apply RFC 6902 JSON Patch. Diff two JSON documents into an add / remove / replace / move / copy / test operation sequence, or apply a patch to a target document. Runs locally.

Format and validate NDJSON / JSON Lines. Each line is parsed independently: valid input is pretty-printed per record with a count, and any bad line reports its exact line and column.

Flatten nested JSON into a single-level object with path keys such as user.name, user.tags[0] and server.port. Configurable delimiter and array notation. Runs locally in your browser.

Unflatten a single-level object with dotted path keys back into nested JSON — turn user.name and user.tags[0] into nested objects and arrays. Configurable delimiter. Runs locally.

Apply an RFC 7396 JSON Merge Patch: keys in the patch overwrite the target, null deletes a key and a non-object patch replaces the target entirely. Simulates an HTTP PATCH. Runs locally.

Generate an RFC 7396 JSON Merge Patch from two JSON documents. Only the changed parts are kept, ready to send as an HTTP PATCH body. Runs locally in your browser.

Resolve an RFC 6901 JSON Pointer such as /users/0/roles/1 against a JSON document. Returns the value at that node and its type, with ~0 / ~1 escaping handled. Runs locally.

Convert JSON to YAML while keeping the original structure, in a format that is easier to read and comment. Conversion errors point to the source position.

Convert YAML to JSON online. Anchors, merge keys and flow syntax are expanded and parsed under the YAML 1.2 core schema, avoiding implicit-type traps such as yes/no and dates. Runs locally.

Convert JSON to clear, semantic TOML config. Nested objects become [section] tables and object arrays become [[array]] tables. Data TOML cannot express, such as null or an array root, is flagged with its field path.

Convert TOML such as Cargo.toml or app config to standard JSON. Tables and array tables are expanded, dates become ISO strings and integers outside the safe range are flagged. Runs locally.

Convert JSON to well-formed XML with an XML declaration and indentation. The root element and array item tag names are configurable, and arrays become repeated same-name elements. Runs locally.

Convert XML to a JSON object. Attributes are kept as @_-prefixed fields by default, text alongside attributes uses a #text key, and attributes can be ignored. Validated first, runs locally.

Convert an array of objects into CSV you can open in Excel or WPS. Columns are the union of all keys, nested objects flatten to dot-separated names, and comma, semicolon, pipe or tab delimiters are supported.

Convert CSV exported from Excel or WPS into an array of objects. The first row becomes the field names, numbers, booleans and null are inferred, and the delimiter is auto-detected. Runs locally.

Convert JSON to Java .properties key-value config. Nested objects flatten to dotted paths, values are escaped to the java.util.Properties rules, and non-ASCII text is written as UTF-8. Runs locally.

Convert Java .properties / i18n resource files into nested JSON. Line continuations, # and ! comments, \uXXXX escapes and = / : / whitespace separators are all supported. Runs locally.

Convert Java .properties / i18n files straight into nested YAML. Continuations, comments, \uXXXX escapes and all separators are supported, with dotted paths restored to nested maps. Runs locally in a Web Worker.

Merge line-delimited JSON (NDJSON / JSON Lines) into a single JSON array, ready for JSON.parse. Indentation and key sorting are configurable.

Split a JSON array into line-delimited NDJSON (JSON Lines) — one record per line — for logs, streaming APIs and bulk imports.

Convert standard JSON to relaxed JSON5 with single quotes, unquoted keys and trailing commas. Quote style and indentation are configurable.

Parse JSON5 — single quotes, unquoted keys, trailing commas and comments — and convert it back to strict, standards-compliant JSON.

Convert JSON into a JavaScript object literal with an optional const, export const, module.exports or bare-literal wrapper and a configurable variable name.

Turn a JSON array into SQL INSERT statements, with column names taken from the union of all fields and a choice of standard, MySQL or Postgres dialects.

Turn a JSON array of objects into a GitHub-flavoured Markdown table, with fields becoming headers and numbers optionally right-aligned.

Convert a JSON object into .env KEY=value pairs, flattening nested fields into dot paths with an optional export prefix and UPPER_SNAKE_CASE keys.

Convert a JSON object into an INI configuration, turning nested objects into [section] blocks with a configurable = or : separator.

Generate Java POJOs from JSON with fields, getters/setters and type inference. Choose Jackson, Lombok + Jackson or a plain POJO, and set a custom package name. Runs locally in a Web Worker.

Generate C# model classes from JSON. Supports both System.Text.Json and Newtonsoft.Json attributes, a custom namespace and root class name, with PascalCase property naming. Runs locally.

Generate Go structs from JSON with json tags. Nested objects become well-named sub-structs, with a custom package name and configurable omitempty style. Runs locally in your browser.

Generate TypeScript interface or type definitions from a sample JSON payload.

Generate Python @dataclass classes from JSON. Choose Python 3.6–3.10 syntax (annotations, built-in generics, PEP 604 unions) and get snake_case field names automatically. Runs locally.

Generate Kotlin data classes from JSON. Supports Jackson, kotlinx.serialization and Klaxon, with a custom package name and accurate nullable (?) type annotations. Runs locally.

Generate Rust structs from JSON with serde derives. Optional fields are wrapped in Option<T>, and nested objects and Vec<T> are expanded. Runs locally in your browser.

Generate Swift models from JSON that conform to Codable. CodingKeys handle snake_case mapping, and optional properties are inferred. Choose struct or class. Runs locally in your browser.

Generate Dart model classes for Flutter projects from JSON, including fields, a constructor and fromJson / toJson methods, with accurate nullable types and json_serializable or Freezed styles.

Infer a JSON Schema from a sample JSON document, merging similar fields and marking required properties.

Generate example data from a JSON Schema. Supports const / enum / default / examples, local $ref (definitions / $defs), allOf / oneOf / anyOf and semantic format placeholders such as email, date-time and UUID.

Validate JSON data against a JSON Schema (draft-07) in your browser. Each failure lists the violated keyword, the JSON Pointer path in the data and the line and column for quick debugging.