Developer Tools

10 free, browser-based developer utilities — JSON, JWT, Base64, Regex, SQL, and more. Zero installation, zero registration.

Browser-Based Developer Utilities

All developer tools on Calculent process data entirely in your browser. No data is sent to any server — making them suitable for working with sensitive tokens, private JSON payloads, and internal SQL queries without security concerns. No installation, no sign-up, no API keys.

10
Dev Tools
0ms
Server Latency
🔒
Privacy Safe

All Developer Tools

JSON Formatter & Validator Beautify, minify, and validate JSON with error highlighting JWT Decoder Decode JWT header, payload, and expiry instantly Base64 Encoder/Decoder Encode and decode Base64 strings and data URIs Regex Tester Real-time regex pattern matching with match highlighting URL Encoder/Decoder Percent-encode and decode URLs and query strings SQL Formatter Format and beautify SQL queries for readability CSS Minifier Remove whitespace and comments from CSS files HTML Minifier Compress HTML for production deployment JavaScript Minifier Minify JavaScript code for faster page loads Timestamp Converter Convert Unix timestamps to human-readable dates

Why Use Browser-Based Developer Tools?

When working with sensitive JWT tokens, internal API payloads, or production database queries, using online tools that send data to external servers creates security risks. Calculent's developer tools process everything locally using JavaScript — your sensitive data never leaves your device.

This makes Calculent appropriate for use in enterprise environments where data-handling policies prohibit third-party server transmission. All tools work offline after the first load (PWA), making them available even in air-gapped development environments.

Frequently Asked Questions

Is it safe to paste my JWT token into an online decoder?

Yes — when the tool processes data entirely in your browser (as Calculent does). JWT payloads are Base64-encoded, not encrypted. Any JWT decoder reads the same data your browser already has. The danger is tools that send your token to a server. Calculent's JWT Decoder uses only client-side JavaScript — your token is never transmitted.

What is the difference between JSON formatting and JSON validation?

JSON formatting (beautifying) adds whitespace and indentation to make JSON human-readable — it does not change the data. JSON validation checks that the JSON is syntactically correct (double quotes on keys, no trailing commas, valid value types). The JSON Formatter & Validator performs both simultaneously, highlighting the exact line and character of any syntax error.

How do I convert a Unix timestamp to IST (India Standard Time)?

Use the Timestamp Converter. Unix timestamps are always in UTC. IST = UTC + 5 hours 30 minutes. In JavaScript: new Date(timestamp * 1000).toLocaleString('en-IN', {timeZone:'Asia/Kolkata'}). The converter handles both seconds (Unix) and milliseconds (JS) automatically.