Free JSON Toolkit
Every JSON Tool You Need — In One Private, In-Browser Suite
11 free JSON tools that run entirely in your browser. Paste once, move between tools, and never upload a byte.
- 11tools
- 0uploads
- 100%in-browser
- 0accounts
jsons.site is a complete suite of 11 JSON toolsfor developers: a formatter, validator, repair tool, diff, minifier, schema validator, JSONPath query engine and tree viewer, plus converters to CSV, YAML and TypeScript. Every tool shares the same editor and the same rule — your JSON never leaves your browser. There is no upload, no queue and no account, so sensitive payloads, production data and customer records stay on your device where they belong.
Because everything runs locally, the tools are as fast as your machine: formatting, validating or diffing a multi-megabyte document happens in milliseconds with no server round-trip. Use theOpen in menu to send the same document straight from one tool to the next without re-pasting it.
Which JSON tool do I need?
Start from your situation — each card goes straight to the tool that solves it.
- My JSON won't parse and I don't know whyvalidate it and see the exact line and column
- My JSON is broken and I want it fixed nowrepair broken JSON automatically
- I need unreadable JSON to be readableformat it with the JSON Formatter
- I need to understand a deeply nested responseexplore it in the JSON viewer
- Two versions of a document changed and I need to know whatdiff them side by side
- I need JSON in a spreadsheetconvert it to CSV
- I'm writing Kubernetes, Docker or CI configconvert it to YAML
- I need TypeScript types from sample datagenerate TypeScript interfaces
- I need to extract one value from a huge payloadquery it with the JSONPath finder
- I need a smaller payload for productionminify it and see the byte savings
- I must check data against a formal schemavalidate it against a JSON Schema
All 11 tools at a glance.
Every tool is free with no limits. Pick the one that matches your job — or start at the formatter and use Open in to hop between them.
- 01ToolJSON FormatterBeautify, sort, validate and explore JSON with syntax highlighting and exact error positions.Best forDaily reading & cleanup of API responses
- 02ToolJSON RepairRewrite broken JSON automatically — trailing commas, single quotes, comments and LLM output — with every change shown.Best forFixing truncated, quoted or LLM-generated JSON
- 03ToolJSON ValidatorCheck syntax against RFC 8259 and see the exact line and column of each error.Best forPre-flight checks before an API call
- 04ToolJSON Schema ValidatorValidate data structure against a JSON Schema draft, powered by Ajv, with clear error messages.Best forCI-style contract checks against a spec
- 05ToolJSON MinifierStrip all optional whitespace and see exact byte savings for API payloads.Best forShrinking payloads before production
- 06ToolJSON DiffCompare two documents semantically — reordering keys produces no false changes.Best forReviewing config or API changes between versions
- 07ConverterJSON Path FinderRun JSONPath expressions and click any node to copy its path.Best forExtracting one value from a huge payload
- 08ConverterJSON → YAMLConvert between JSON and YAML in both directions for Kubernetes, Docker and CI configs.Best forKubernetes, Docker and CI configuration
- 09ConverterJSON → CSVTurn an array of objects into spreadsheet-ready CSV with aligned columns.Best forSpreadsheets, Excel and Google Sheets
- 10ConverterJSON → TypeScriptGenerate TypeScript interfaces from real data with sensible optionality.Best forTyping sample data in a codebase
- 11ToolJSON ViewerExplore nested data as a collapsible tree with search and path copying.Best forExploring unfamiliar nested structures
How the suite works together.
Real JSON work is a chain, not a single action — this is the pipeline most documents travel:
Paste an API response once, then move it through the pipeline without ever uploading it:validate it to confirm it parses,repair it if it doesn't,format it for reading, diff itagainst the previous version, and convert it toCSV,YAMLor TypeScriptwhen the data moves downstream. Every page carries the same document forward withOpen in, so nothing is pasted twice.
Why client-side processing matters.
Most online JSON tools upload your document to a server before they touch it. That is fine for a public API response and unacceptable for anything else — customer records, tokens, internal configs, health or financial data. Every tool here parses and transforms JSON with JavaScript on your own device, so there is no third party in the middle, nothing queued on a server, and no file-size limit imposed by an upload. The details are documented on theprivacy policy page, including the single network request a tool can make: fetching a URL you explicitly provide.
Built for developers, by developers.
- StandardRFC 8259 JSON, strictlyNo lenient modes — malformed documents are reported with exact positions.
- QueryingJSONPath per RFC 9535Filters, slices and recursive descent implemented to the current spec.
- SchemaDrafts validated with AjvContract checks with readable error messages, the same engine CI pipelines use.
- InterfaceNo third-party scripts or fontsKeyboard shortcuts, dark mode, syntax highlighting — every asset self-hosted.
Want to know who builds it or how the site works? Read moreabout jsons.site.
FAQ.
What is jsons.site?
A suite of 11 free browser-based JSON tools — formatter, validator, repair, diff, minify, schema validation, JSONPath, tree viewer, and JSON to CSV, YAML and TypeScript converters — built for developers who want speed without sending data to a server.
Are all the JSON tools really free?
Yes. Every tool is completely free with no usage limits, no accounts, no watermarks and no paid tier. The same features are available to everyone, whether you format one document or a thousand.
Does my data ever leave my browser?
No. JSON is parsed, transformed and rendered by JavaScript running on your device — there is no upload step and no server-side processing. The only network request a tool can make is fetching a URL you explicitly ask it to load.
Do I need an account or installation?
Neither. The tools run in any modern browser straight from the page, with nothing to install and nothing to sign up for. Your theme choice and any local history stay in your own browser storage.
Which tool should I use for broken JSON?
Start with the JSON Validator to see the exact line and column of each syntax error, then use JSON Repair to rewrite the document automatically — the repair tool shows you every change it makes before you copy the result.