Jace - JSON Editor
JSON files, finally friendly
Only for Mac
Free
Mac
New in 1.1: semantic compare shows which keys and values actually changed — plus multi-node selection, drag-to-reorder tree editing, and a faster launch screen.
Explore JSON as a tree, edit the source beside it, and compare two documents to see exactly what changed — with search, formatting, parse feedback and Quick Look.
Jace makes JSON viewing and editing a breeze. An interactive tree and a syntax-highlighted source editor stay side by side, so you can understand a document, make changes, and keep your place without switching views.
COMPARE, SEMANTICALLY • Compare the open document with a file, your clipboard, or pasted text • Differences are matched by key and value, so you see real changes rather than shifted lines • Counts and filters for added, removed and changed, with a navigator for the whole hierarchy • Inspect both sides of a difference together, with the JSON path ready to copy • Decide whether object property order counts; arrays are always compared by position • Start a comparison from the launch screen without opening a document first
EXPLORE AND EDIT • Expand and collapse objects and arrays • Edit keys, strings and numbers directly in the tree, and toggle booleans with a click • Duplicate, sort or remove any node, and drag nodes to reorder them or move them elsewhere • Select several nodes with ⇧-click or ⌘-click and remove them together, as one undo step • Select a tree node to jump to its source, or place the cursor in the source to highlight the matching node
FIND AND FORMAT • Search across keys and values, with matches highlighted and a count you can step through • Prettify or minify from the toolbar or with keyboard shortcuts • Choose your indentation width and editor font size • See line numbers, syntax highlighting, document size, line count and JSON parse status
BUILT FOR REAL-WORLD FILES • Use familiar macOS document workflows for opening, editing, saving and undoing changes • For documents 50 MB and larger, Jace switches to a dedicated large-file mode for smooth interactions • Keep recent files and in-progress drafts within reach • Preview .json files from Finder with the included Quick Look extension
Jace stays focused on one job: helping you read, change and compare JSON without losing sight of its structure. Open a file and get to work — no account or workspace setup required.
Ratings & Reviews
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Jace 1.1 adds semantic comparison, hands-on tree restructuring, and a faster way to start.
SEMANTIC COMPARE • Compare the open document against a file, your clipboard, or pasted text • See which keys and values actually differ — not which lines moved • Added, removed and changed counts, with a filter for each • Step through differences or jump straight to one in the navigator • Inspect both sides of any difference, with its JSON path ready to copy • Duplicate keys are matched by occurrence, so nothing is silently merged • Choose whether object property order counts; arrays are always compared by position • Compare two inputs from the launch screen, without opening a document first
RESTRUCTURE IN THE TREE • Select several nodes with ⇧-click or ⌘-click, then remove them in a single undo step • Selecting a container takes its whole subtree with it, so nothing is half-deleted • Drag a whole selection into a new position • Duplicate, sort or remove any node from its context menu • Sort children by key or by value, ascending or descending — or recursively • Drag nodes to reorder them, or to move them into another object or array • Every change is a normal undo step, and the source updates with it
A FASTER START • New launch screen: start a draft, turn the clipboard into one, open a file, or compare • Search now lives in the tree pane, with a match count and quick stepping between hits
REFINEMENTS • Liquid Glass materials on macOS 26, with the earlier appearance on older systems • Smoother transitions moving between editing, comparing and searching • Jace now requires macOS 15 or later
The developer, Shao-Yu Liang, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Linked to You
The following data may be collected but it is not linked to your identity:
- Location
- Identifiers
- Usage Data
- Diagnostics
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Shao-Yu Liang
- Size
- 2.9 MB
- Category
- Developer Tools
- Compatibility
Requires macOS 15.0 or later.
- Mac
Requires macOS 15.0 or later.
- Mac
- Age Rating
4+
- 4+
- Copyright
- © 2026 Andy Liang
