Genuinely native
An AppKit app built over a Rust core, not a browser in a window. It stays quick on big documents, where web based editors crawl.
Professional JSON Schema Authoring Environment
JSON Design Studio
Author and validate JSON, JSON Schema, YAML, and XML in a fast, native app. Work with JSON in the code editor, in an editable grid, or in the visual designer, and validate against every JSON Schema draft, completely offline.
Version 0.6.5 · macOS 13 Ventura or later · Apple Silicon · ~5 MB
Free for personal and commercial use under the End User License Agreement.
Every draft, offline
Validate against JSON Schema Draft 4, 6, 7, 2019-09, and 2020-12, auto detected from $schema, without touching the network.
Three ways to work
Switch a single document between a syntax highlighted Code editor, an editable Grid, and a visual schema Design canvas.
One document, three views
Edit JSON in the view that fits the task
Every view edits the same underlying document through the same engine, so they never disagree, and structural edits preserve your existing formatting, byte for byte.
Text, a real editor
Syntax highlighting for JSON and YAML, line numbers, code folding, inline error squiggles, and find and replace. The status bar shows well formedness, validation state, the detected schema draft, and the JSON Pointer under your caret as you move.
- Highlighting for JSON and YAML, with folding and find and replace
- Error squiggles at the exact line and column
- Live JSON Pointer for the caret; jump to any pointer or line
Grid, structure you can edit
See the document as an outline of keys, types, and values. Rename keys, edit values, change a node's type, and add, remove, or duplicate nodes, then copy the JSON Pointer to any node. Edits touch only the bytes that change, so the rest of your file's formatting survives untouched.
- Rename keys, edit values, change types in place
- Add, remove, and duplicate nodes; copy JSON Pointers
- Format preserving, so diffs stay small and reviewable
Design, a visual schema editor
Build and read JSON Schema the way you would in an XML schema tool. The Design view lays out properties, $defs, items and prefixItems, compositions (oneOf, anyOf, allOf, not), conditionals, and $ref targets, with an inspector for titles, descriptions, types, required flags, formats, patterns, enums, and ranges.
- Drag friendly palette of schema constructs and groups
- Follow
$reftargets and jump to definitions - Edits write clean schema, and the schema is meta validated as you go
Validation you can trust
Find every problem, with the path to fix it
The problems panel lists every failure, not just the first, each with a human readable message, the failing keyword, and the instance path. Double click to jump straight to it in any view.
Strict and offline by default
Relative $refs resolve against the schema's folder; remote URIs can be mapped to local files so validation never reaches the network. Lenient mode is an explicit opt in.
Schemas check themselves
Open a schema and it is automatically meta validated against its own draft's meta schema, so the schema you are writing is correct before you ever point data at it.
Batch and conformance testing
Validate whole folders or glob patterns against a schema with per file results, and run reusable test suites of known valid and known invalid fixtures.
Batteries included
The everyday JSON toolbox, built in
The conversions and generators you usually paste into a half trusted website, here, native and offline.
- JSON to and from YAML
- JSON to and from XML (BadgerFish)
- JSON to and from CBOR
- Pretty print and minify
- Sort properties and enum values
- Escape and unescape strings
- Infer a schema from samples
- Generate sample JSON from a schema
- Migrate a schema to draft 2020-12
- JSONPath queries
- Generate docs from schema
- Compare documents (text and structural)
- Code generation: TypeScript, Python, Java, Go
- Go to JSON Pointer
- Bundled OpenAPI 3.0, 3.1, and Swagger 2.0
Query, then jump to the match
Run a JSONPath expression and get every match with its line, JSON Pointer, type, and value, then click a result to land on it in the document. Pair it with Go to JSON Pointer and the live caret pointer in the status bar to navigate large files without scrolling blind.
Built for schema authors
Design it. Test it. Trust it.
Everything you need to evolve a schema with confidence: pattern driven test suites, flexible schema resolution, and the entire SchemaStore catalog at hand.
Test suites you define with patterns
Describe a suite once: a folder of fixtures, a regex for the valid cases and one for the invalid ones, and a schema template whose placeholders are filled from the pattern's capture groups. One definition can cover hundreds of fixtures across many schema versions, without listing a single file by hand.
- Valid and invalid cases selected by regex, with capture groups picking the schema
- One suite per schema, or a single suite spanning every version
- Definitions live in app preferences; nothing is written into your spec folders
Run them, and see exactly what passes
One click runs the whole suite and reports a live pass rate with a per fixture breakdown, so you always know which cases pass and which fail as a schema changes. The moment a once valid document stops validating, you will see it. Pictured: a CycloneDX 1.7 conformance suite, 90 fixtures, all green.
- Per fixture pass and fail, with jump to failure
- A running count and percentage for the whole suite
- Catch regressions before they ship
Point each file at the right schema
Associate any JSON or YAML file with a specific schema, so it validates the instant you open it. And map a schema's $id (typically a URL) to a local file, so you can validate against a schema that is not deployed yet, while it is still under development on your disk.
- Map a file to a specific schema, local or remote
- Map a schema
$idor URL (or a URL prefix) to a local file - Develop a schema and validate against it before it is ever published
The whole SchemaStore catalog
Validate against any of the roughly 1,300 schemas in the public SchemaStore catalog. A snapshot is bundled so it works offline; the live catalog refreshes in the background.
Automatic schema detection
Files whose names match a SchemaStore, OpenAPI, or Swagger pattern validate automatically, with no setup. Toggle it off whenever you want full manual control.
Tidy, reviewable schemas
Sort properties by name and sort enum values, keeping each value's meta:enum documentation aligned, so diffs stay clean and reviews stay sane.
Spell check, built for standards
Check the prose in titles, descriptions, and documentation against American, British, or Oxford English. Oxford spelling is what international standards bodies such as Ecma and ISO commonly require.
Also bundled: official OpenAPI 3.0, 3.1, and Swagger 2.0 schemas (documents declaring openapi or swagger validate automatically, offline), per value enum docs via meta:enum in generated documentation, per document draft overrides, and a lenient mode that ignores unresolvable $refs, which you can opt into per validation.
Version control, built in
Commit without leaving the editor
A real Git client lives right inside the workspace, so a schema and its test fixtures stay in lockstep without a context switch to a terminal or a separate app.
See what changed, then commit it
Review exactly what changed in an inline, colored diff, then stage and commit, switch or create branches, and update from origin, all from the panel and the status bar.
- Review changes with an inline, colored diff
- Stage, commit, and manage your
.gitignore, from the panel or the file tree - Switch or create branches and update from origin, right from the status bar
- Roll back changes, or shelve them to return to later
Make it yours
Themes, not just a dark mode
Default Light, Default Dark, and Match System out of the box, plus all four Catppuccin flavors. Themes are plain data, so the palette extends easily. Every control is themed; nothing falls back to a stock look.
Default Light Default Dark Catppuccin Latte Frappé Macchiato Mocha
Your documents stay on your Mac
No account, no sign in, no telemetry. Everything runs locally. The only network requests are optional downloads of remote schemas you reference, and you can map those to local files to stay fully offline.
Free, and free to use commercially
JSON Design Studio is freeware. Use it at home or at work, on as many of your Macs as you like, at no cost. It is not open source; the full terms are in the End User License Agreement.
Download
Get JSON Design Studio
A signed disk image for Apple Silicon Macs. Drag the app to your Applications folder and you are done.
First launch: if macOS says the app is from an unidentified developer, right click the app and choose Open, or clear the quarantine flag:
xattr -dr com.apple.quarantine "/Applications/JSON Design Studio.app" - Version0.6.5
- RequirementsmacOS 13 Ventura or later
- ArchitectureApple Silicon
- Download size~5 MB
- PriceFree
- FormatsJSON · YAML · XML
- Schema drafts4 · 6 · 7 · 2019-09 · 2020-12
- Version controlGit, built in
Questions
Good to know
Is it really free?
Yes. JSON Design Studio is freeware, free for personal, educational, professional, and commercial use, on as many of your Macs as you like. There is no account and no trial. It is distributed under a proprietary end user license (it is not open source), included with the download. See the license.
What do I need to run it?
An Apple Silicon Mac (M1 or later) running macOS 13 Ventura or newer.
macOS will not let me open it. Is something wrong?
No. Apps downloaded from the web are quarantined by Gatekeeper. On first launch, right click (or Control click) the app and choose Open, then confirm. Alternatively, run this in Terminal:
xattr -dr com.apple.quarantine "/Applications/JSON Design Studio.app"Which JSON Schema drafts are supported?
Draft 4, draft 6, draft 7, 2019-09, and 2020-12. The draft is auto detected from the schema's $schema keyword, and you can override it per document. Schemas are also meta validated against their draft's meta schema.
Does it send my data anywhere?
No. It is a native, local app with no telemetry and no account. Validation runs entirely on your Mac. The only time it reaches the network is to fetch a remote schema you explicitly reference by URL, and even that can be avoided by mapping remote URIs to local files for fully offline validation.
Can it handle large documents?
Yes. Parsing, validation, and structural edits live in a Rust core, and the Swift interface never parses the document itself. That keeps it responsive on large files where browser based tools tend to stall.
Do I need anything set up to use the Git features?
Just the standard git command, which comes with the Xcode Command Line Tools on macOS. JSON Design Studio drives your existing git install, so it works with the repositories and credentials you already have. The Git panel and branch control appear automatically when the file you are editing lives in a repository.
Which spell check dictionaries are included?
American, British, and Oxford English are included and run offline, like the rest of the app. Oxford English (Oxford spelling) is the variant international standards bodies such as Ecma and ISO commonly require, so you can check a specification against the spelling it mandates.
Will there be an Intel or older macOS build?
The current release targets Apple Silicon and macOS 13 or later. There is no Intel build today.
Get JSON Design Studio
Version 0.6.5 for Apple Silicon. Free to download and free to use, at home or at work. Your documents never leave your Mac.