Privacy‑first JSON tools for developers
Format, validate, compare, repair, and convert JSON in seconds — with local, in‑browser processing (no uploads).
- No uploads: your input stays on your device
- Fast: optimized for API responses and large payloads
- Developer UX: validation, diffs, tree views, exports
JSON Formatter Preview
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"name": "DataFormatter Pro",
"version": "1.0.0",
"features": [
"JSON formatting",
"Validation",
"Conversion"
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"stats": {
"users": 12500,
"rating": 4.9
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}- 30+ structured data utilities
- Format, diff, repair, and convert JSON
- Works in‑browser — no backend required
- No uploads required to process your input
- Runs client‑side in your browser
- Offline‑ready (PWA/service worker)
- Opens instantly, zero setup
- No sign‑up, no API keys
- Use what you need, when you need it
Explore tool-specific pages:
Start here
The fastest path from “broken payload” to “shippable data.” Pick a tool and get back to building.
JSON Formatter
Professional JSON formatter with real-time validation, syntax highlighting, tree view, and multi-format conversion. Format JSON online free, validate JSON syntax, and convert to XML/CSV/YAML instantly.
- Real-time validation
- Convert to XML/CSV/YAML
- Interactive tree view
JSON Compare
Advanced side-by-side JSON comparison with visual diff highlighting, change tracking, and export options. Perfect for debugging and version control.
- Visual diff view
- Array comparison modes
- Export HTML/JSON Patch
JSON Repair
Fix broken JSON automatically: quotes, commas, brackets, comments, JSONP wrappers, and common dev formats. Perfect for malformed API responses and LLM outputs. Runs locally in your browser—no uploads.
- One-click repair + confidence score
- Before/after diff + repair log
- Paste / upload / URL / sample input
JSON Editor
Visual JSON editor with tree view and Monaco editor. Inline editing, drag-and-drop reordering, type conversion, and context menu operations.
- Tree & Monaco editor modes
- Drag & drop reordering
- Inline editing & validation
JWT Decoder
Decode JWT tokens to view header, payload, signature, and claims. Check expiration and algorithm details.
- Token breakdown
- Expiration checker
Excel to JSON Converter
Convert Excel spreadsheets (.xls, .xlsx) into clean JSON instantly. Multi-sheet support, preview, multiple JSON formats, and private client-side conversion.
- .xls + .xlsx support
- Multi-sheet selection + preview
- Copy + download + share
Explore 30+ JSON tools and converters — free, fast, and browser-based.
Built like a developer tool
Local processing, fast workflows, and clean output — so you can spend less time fighting data.
No uploads
Your JSON is processed in your browser. Great for sensitive payloads and confidential configs.
Local-first workflow
Paste, validate, repair, compare, convert, export — without sending your input to a processing server.
Use what you need
No registration required. Use the tools you need, when you need them.
Workflow features (the stuff you actually need)
Designed for API engineers, analysts, and developers — validate, transform, inspect, and ship.
Validate & pinpoint errors
Clear error messages with line/column focus so you can fix broken payloads quickly.
Repair malformed JSON
One-click fixes for common issues (quotes, commas, wrappers, comments) — great for logs and LLM outputs.
Compare changes
Side-by-side diffs for config edits, API regressions, and contract changes.
Convert between formats
JSON ↔ CSV / XML / YAML / Excel — with clean output and sensible defaults.
Inspect structure
Tree views, syntax highlighting, search, and navigation for nested objects and arrays.
Tunable output
Indentation, sorting, wrapping, minify/beautify, and export options that match team conventions.
Ship cleaner JSON in minutes
Start with the JSON Formatter, then use Compare, Repair, and converters as you go.
Frequently Asked Questions
Quick answers about privacy, limits, and workflows.
Simply paste your JSON into our JSON Formatter tool and click the "Format" button. The tool will automatically beautify your JSON with proper indentation and syntax highlighting. You can adjust the indentation size in the settings.
Yes. Use the JSON Validator for strict syntax checks and clear error locations. For messy inputs (logs, comments, LLM output), try JSON Repair first.
Most tools handle large files in-browser (often up to ~10MB depending on device). For very large payloads, splitting the file or focusing on a subset is usually fastest.
We support conversions (e.g. JSON ↔ XML/YAML) in several tools. Dedicated formatters/validators are on the roadmap — if you have a specific workflow, send it via the Contact page.
Yes! All our current tools are completely free with no signup required. We may offer premium features in the future, but core formatting functionality will remain free.
Data Formatter Pro offers the most comprehensive JSON formatting tools with real-time syntax validation, customizable indentation, and support for large files up to 10MB. Perfect for API development, configuration management, and data analysis workflows.
Use our JSON to CSV converter to transform JSON arrays into Excel-compatible CSV files. Supports nested objects, custom delimiters, and automatic header generation. No registration required, completely free.
Yes — formatting/validation/conversion run locally in your browser (no upload required to process your input). If you’re extra cautious, you can also use the site offline after the first load.