Developer utilities, run locally
Tools that never phone home.
JSON formatting, diffing, encoding, generators — the everyday utilities you reach for ten times a day, built to run entirely in your browser tab. No accounts, no uploads, no tracking pixels reading your data.
{
"name": "nullpath",
"requests_sent": 0,
"runs": "entirely-in-browser",
"tools": [
"json-formatter",
"json-diff"
]
}Available now
Start with these
JSON
JSON Formatter & Validator
Format, minify, validate, and browse JSON as a collapsible tree.
JSON
JSON Diff
Compare two JSON documents and see what was added, removed, or changed.
JSON
JSON to CSV
Convert a JSON array of objects to a CSV table.
JSON
JSON to YAML
Convert JSON to block-style YAML.
JSON
JSON to TypeScript
Generate TypeScript interfaces from JSON examples.
JSON
JSON to Schema
Generate JSON Schema (draft 2020-12) from JSON examples.
JSON
JSON Schema Validator
Validate a JSON document against a JSON Schema.
JSON
CSV Viewer
View and convert CSV to JSON in your browser.
Encoding
Base64 Encode / Decode
Convert text and files to and from Base64.
Encoding
URL Encode / Decode
Percent-encode or decode a URL or query string.
Encoding
HTML Encode / Decode
Escape or unescape HTML entities.
Formatting
XML Formatter
Pretty-print and validate XML documents.
Formatting
XML Diff
Compare two XML documents and see what was added, removed, or changed.
Formatting
Regex Tester
Test regular expressions with live highlighting and capture groups.
Formatting
YAML Formatter & Validator
Pretty-print, minify, and validate YAML documents.
Encoding
ASCII / Text Converter
Convert between text, ASCII codes, and hex.
Generators
UUID Generator
Generate v4 UUIDs in bulk, in your browser.
Generators
Unix Timestamp Converter
Convert Unix epoch timestamps to dates and back.
Security
JWT Decoder
Decode JWT header and payload locally, in your browser.
Security
Hash Generator
Generate MD5, SHA-1, SHA-256, SHA-384, and SHA-512 hashes.
Why local-only
Your input never leaves this tab.
01 · No server round-trip
Parsing and formatting run in JavaScript, on your device. There's no API call to wait on, and no backend that could log what you pasted.
02 · Verifiable, not just claimed
Every tool page shows a live count of outgoing network requests. Watch it stay at zero while you work.
03 · Fast by default
No frameworks to hydrate, no analytics beacons to wait on. Pages ship as near-static HTML.