Format JSON
Beautify and pretty-print JSON with custom indentation.
— Paste JSON
Input
Formatted Output
Output will appear here
Validate JSON
Check JSON syntax and see the exact line and position of any error.
— Paste JSON
Input
Validation Report
Output will appear here
JSON Repair
Fix broken JSON — trailing commas, single quotes, unquoted keys, comments, and more.
— Paste broken JSON
Broken JSON
Repaired JSON
Output will appear here
Minify JSON
Remove all whitespace and compact JSON to a single line.
— Paste JSON
Input
Minified Output
Output will appear here
JSON Tree Viewer
Visualize JSON as an interactive collapsible tree. Click any node to expand or collapse.
— Paste JSON
JSON Input
Tree View
Tree will appear here
JSONPath
Extract values from JSON using JSONPath expressions like $.store.books[*].title or $..price.
— Enter path and JSON
JSON Input
Matches
Results will appear here
JSON → CSV
Convert a JSON array of objects to a CSV file. Column headers are extracted automatically.
— Paste JSON array
JSON Array Input
CSV Output
Output will appear here
JSON → YAML
Convert JSON to clean YAML format, browser-based with no server required.
— Paste JSON
JSON Input
YAML Output
Output will appear here
Schema → JSON
Generate sample JSON data from a JSON Schema. Supports type, properties, items, enum, default, and more.
— Paste JSON Schema
JSON Schema Input
Generated JSON
Output will appear here
JSON / Text Diff
Compare two JSON or text documents line by line. Highlights added, removed, and changed lines.
Original (A)
Modified (B)
Diff Output
Diff will appear here
JWT Decoder / Encoder
Decode JWT tokens instantly or encode a header + payload into a JWT. Processing is 100% client-side.
JWT Token
— Paste JWT
Header
Header will appear here
Payload
Payload will appear here
Signature
Signature (not verified)
Header JSON
Payload JSON
Encoded JWT (unsigned)
Encoded JWT will appear here

Note: This creates an unsigned JWT (no signature). Use your backend to sign with a secret.

Base64 Encoder / Decoder
Encode text to Base64 or decode Base64 to text. Supports UTF-8 characters.
— Paste text
Text Input
Base64 Output
Output will appear here
RegEx Tester
Test regular expressions live. See all matches highlighted and capture groups listed.
Flags:
— Enter a pattern
Test String
Highlighted Matches
Matches highlighted here
Hash Generator
Generate SHA-1, SHA-256, SHA-384, SHA-512 hashes from text or files. All computed locally — nothing is uploaded.
— Enter text or pick a file
Input
All Hashes
Results will appear here
Timezone Overlap
Find overlapping working hours across timezones. Add your team's timezones and see the green overlap window.
:00 to :00
Working hours Overlap (all available) Current UTC hour
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FAQ

Frequently Asked Questions

Is NotchLint free?
Yes, NotchLint is completely free with no account required. All 15 tools are free forever.
Is my data sent to a server?
No. All processing happens entirely in your browser using JavaScript. Your JSON, JWT tokens, and other data never leave your device.
What tools does NotchLint include?
NotchLint includes 15 tools: Format JSON, Validate JSON, JSON Repair, Minify JSON, JSON Tree Viewer, JSONPath extractor, JSON to CSV, JSON to YAML, JSON Schema to JSON, JSON/Text Diff, JWT Decoder/Encoder, Base64 Decoder/Encoder, RegEx Tester, Hash Generator, and Timezone Overlap Finder.
How do I decode a JWT token?
Open the JWT Decoder tool, paste your JWT token, and click Decode. The header and payload will be decoded and displayed as formatted JSON instantly.
Can NotchLint repair broken JSON?
Yes. The JSON Repair tool fixes common issues like trailing commas, single quotes instead of double quotes, unquoted keys, and JavaScript-style comments.
What is JSONPath and how do I use it?
JSONPath is a query language for JSON, similar to XPath for XML. Use expressions like $.users[*].email to extract all emails, or $..price to recursively find all price fields.