Open a messy JSON dump or a whole NDJSON log and read it as a sortable, filterable grid. Query it, flatten it, export to Excel. No jq, no online formatters, nothing leaves your machine.
| Specifications | |
|---|---|
| Formats | JSON · JSON Lines / NDJSON · log files · XML & TOON (read-only). TOON: macOS and browser demo. |
| Files | Up to 50 MB, several at once as tabs |
| Views | Nested grid · tree · flat (every leaf a column) |
| Query | JSONPath subset, e.g. $.rows[?(@.status=="ERROR")], composes with sort, filters and editing |
| Ask | Plain-English queries, opt-in, with your own Anthropic key; the request is shown before it is sent |
| Filters | Excel-style per-column value checklist, funnel indicators, column profiling |
| Export | CSV · XLSX with typed cells · Markdown · JSON subtree, exactly the filtered view |
| Editing | In place with type auto-detection and undo; saves are byte-minimal |
| Validation | JSON Schema with inline errors; infer a TypeScript type or JSON Schema |
| Network | None. No sign-up, no cloud, no analytics |
So you paste it into an online formatter you shouldn't trust with prod data, or wrestle jq until the array finally lines up. JSON Analyzer skips all of it: open the file, and arrays of objects are a spreadsheet, one you can sort, filter, query, flatten, and hand to Excel.
Files up to 50 MB open instantly as a dense nested grid, several at once as tabs. JSON Lines, NDJSON and log files open as one table, one row per line. Open XML and TOON files as a grid or tree, with read-only viewing. TOON is available on macOS and in the browser demo.
Press ⌘⇧F and type $.rows[?(@.status=="ERROR")]. Or just ask “rows where status is ERROR” in plain English. Stack Excel-style column filters on top.
Right-click, export the exact visible view to CSV, XLSX, or Markdown. Newlines, commas and quotes inside cells stay intact, which a clipboard copy can't do.
![The JSONPath the app wrote from that question, $.employees[?(@.profile.projects[*].tasks[*].assignedTo.skills.experience.years > 8)], with its 54 matching rows highlighted in the grid.](/assets/query-Cm8iqNIs.webp)
Structure shows through cell containment, not runaway indentation. Expand any node in place; 1k-row chunking keeps huge arrays fluid.
One click flattens any nesting into a single spreadsheet: every leaf becomes a column (user.address.city), arrays expand to rows. Query it like any table.
![JSON Analyzer's flat view: every nested leaf has become its own column, with dotted header names like employees[].name and profile.contact.email, and an export menu offering CSV and XLSX.](/assets/flatcard-Uay_U3Vc.webp)
A documented JSONPath subset. $.rows[?(@.id>3)] filters a table to matching rows in place, and composes with sort, filters and editing.
![JSON Analyzer's query bar running $.employees[*].profile.contact.email, with every matching email cell highlighted in the grid below.](/assets/query-card-ZM6gFR2R.webp)
Type what you want; the app writes the query. “Explain this JSON” summarizes an unfamiliar file's shape. Optional, uses your own Anthropic key, and you preview every request before it's sent.
Per-column value checklist with live counts, funnel indicators, and visible/total tallies. Column profiling on header hover: distinct, min, max, null share.
A real .xlsx with typed numeric cells. No dependency, no upload: what you see filtered on screen is exactly what lands in the file.
Edit scalars in place with type auto-detection and undo/redo. Save is byte-minimal: untouched bytes stay byte-identical to the original.
Check a document against a JSON Schema with inline errors on the exact cells. Going the other way, copy an inferred TypeScript type or JSON Schema from any file.
Compare an API response against yesterday's fixture side by side. Each tab keeps its own view, filters, query, and undo history.
For developers debugging API dumps · QA reading fixtures · support engineers · data analysts
14-day trialEvery download starts with full Pro for 14 days: no account, no card, it just quietly becomes Free.
|
Free
€0
free forever, no account
|
Pro — one-time
€19 then €29 from 15 Sep 2026
pay once, yours forever · not a subscription
|
|
|---|---|---|
| Open & view any JSON as grid or tree | Included | Included |
| JSON Lines / NDJSON / logs as one table | Included | Included |
| Open XML & TOON (read-only; TOON on macOS and browser demo) | Included | Included |
| Sort, flip, resize, expand & collapse | Included | Included |
| Text search · copy value, subtree or path | Included | Included |
| Structural queries + plain-English ask | Not included | Included |
| Column filters & profiling | Not included | Included |
| Flat view | Not included | Included |
| Export CSV, XLSX, Markdown & subtree JSON | Not included | Included |
| Byte-fidelity editing & saves | Not included | Included |
| Multi-file tabs | Not included | Included |
| Schema validation · TS type / JSON Schema inference | Not included | Included |
| Updates within the major version | Included | Included |
|
Download for macOS
On Windows? Read this first
|
Buy Pro — €19
pay once, yours forever
|
The Windows installers aren't code-signed yet, so Windows greets them with a blue “Windows protected your PC” screen. That's expected: click More info, then Run anyway. It's the same app as the macOS build, from the same source. We'll buy a signing certificate once Windows demand covers the yearly cost; until then we'd rather ship it than make you wait.
No sign-up, no cloud, no analytics. Just a fast native app reading files on your own disk.
The two AI features are strictly opt-in: they use your own Anthropic API key, stored in the macOS Keychain or Windows Credential Manager, and show you the exact request (a capped outline of the file's structure) for approval before anything is sent. Skip them and the app never makes a network call at all.
Open it as a spreadsheet, filter to what broke, and export the proof, all in about ten seconds.