Every JSON tool you need, in one place
Format, diagram, diff, query, validate and convert JSON — into CSV, YAML, XML, SQL or typed classes for seven languages. No account, no uploads, no waiting on a server.
Everything you need to work with JSON
Grouped by what you are trying to do. Every tool runs client-side, needs no account, and works offline once loaded — or press ⌘K anywhere on the site to jump straight to one.
Inspect & debug
Read, clean and interrogate a payload you were just handed.
Formatter & validator
Beautify, minify, sort and escape JSON, with parse errors pinned to the exact line and column.
JSON to diagram
Turn any payload into a collapsible, searchable node graph. Export as PNG or SVG.
JSON diff
Compare two payloads structurally — key order ignored — and export an RFC 6902 JSON Patch.
JSONPath tester
Write a path and watch matches update live. Filters, slices and recursive descent.
JWT decoder
Read a token’s header, claims and expiry, and verify HS256 signatures locally.
Schema & test data
Describe the shape of your data, then check and fake it.
JSON Schema generator
Infer a schema straight from a sample payload — draft 2020-12 or draft-07.
JSON Schema validator
Check a payload against a schema and get every failure with its instance path.
Mock data generator
Turn a schema into realistic fake records. Seeded, so the same seed gives the same data.
Convert & export
Move a payload into whatever format the next system speaks.
JSON to code
Generate C# classes, TypeScript interfaces, Dart, Kotlin, Java, Python or Go types.
JSON ⇄ CSV
Convert to spreadsheet-ready CSV and back, with nested objects flattened to dot columns.
YAML ⇄ JSON
Convert either direction with live validation and multi-document YAML support.
JSON ⇄ XML
Convert either direction with attributes preserved, using the browser’s own parser.
JSONL ⇄ JSON
Convert NDJSON logs and LLM datasets to an array and back, with bad lines flagged.
JSON to SQL
Generate CREATE TABLE and INSERT statements for Postgres, MySQL, SQL Server or SQLite.
Built to be shown, not just used
Every tool goes full screen with one keystroke: navigation, headers and options disappear, type scales up for the back of the room, and a presenter toolbar gives you zoom, fit, panel toggles and a laser pointer. Diagrams are SVG, so they stay sharp on any projector.
Open any tool and press ShiftP.
Keep it one click away
Install JSON Studio as an app and it opens in its own window, launches from your dock or start menu, and keeps working with no connection at all. Or add the browser extension to send whatever you have selected on any page straight into a tool.
On iPhone or iPad: tap Share, then Add to Home Screen.
- Offline first. Every tool is cached on install — payload wrangling on a plane works fine.
- Own window. No tab hunting; it behaves like a native app.
- Right-click anywhere. The extension sends selected text into the formatter, diagram or JSONPath tester.
- Still zero backend. Installing changes nothing about privacy — the code is the same, just local.
Built for people who live in payloads
MSDEVBUILD focuses on Azure, AI and mobile architecture — this exists because reading raw API responses and config files all day gets old, and because most free JSON tools want your data on their server first.
Private by construction
No backend exists, so there is nothing to leak, log or subpoena. Watch the network tab — it stays empty.
Instant
No round trip to a server means results appear as you type, even on a 20 MB payload.
Keyboard-first
⌘K jumps between tools, ⌘↵ re-runs the current one.
Light & dark
A proper dark theme, not an inverted filter, remembered across every page.
No sign-up wall
No account, no email capture, no "free tier". Open the page and use it.
Open source
Plain HTML, CSS and JavaScript with no build step. Read it, fork it, add a tool.
Frequently asked
Is JSON Studio really free?
Yes — every tool, no account, no trial, no usage cap. It is a static site with no backend, so there is nothing to meter and nothing to charge for.
Is my data sent anywhere?
No. Every tool runs as JavaScript inside your own browser tab. Nothing you paste, upload or drag in is transmitted to any server. The one exception is opt-in and clearly marked: the diagram page can call OpenAI with your own API key if you choose to use its "explain with AI" panel.
Can I use it offline?
Yes. Install it as an app (the Install button in the header, or your browser’s install option) and every tool is cached for offline use. Even without installing, a page keeps working once loaded.
Is it safe for confidential payloads?
The code never transmits your data, and you can verify that: the source is on GitHub, there is no build step, and you can open DevTools’ network tab and watch it stay quiet. For maximum assurance, install the app or download the repo and open index.html from your own disk.
Which JSON Schema drafts are supported?
The generator emits draft 2020-12 or draft-07. The validator implements the keywords that appear in real-world schemas — types, required, enum, const, numeric and string bounds, items, uniqueItems, contains, additionalProperties, patternProperties, dependentRequired, anyOf/oneOf/allOf/not and local $ref. It is not a full draft implementation.
Can I contribute a tool?
Please do. The project is plain HTML, CSS and JavaScript with no build step, and there is a shared toolkit that handles the boilerplate — see the contributing guide on GitHub.