Developer — free online tools

All Developer tools (23)

• JSON Formatter & Validator — Format, validate, and beautify JSON with syntax highlighting
• Base64 Encoder / Decoder — Encode and decode Base64 strings and files
• URL Encoder / Decoder — Encode and decode URLs and query parameters
• JWT Decoder & Inspector — Decode and inspect JWT tokens with claims validation
• UUID Generator — Generate UUIDs (v1 and v4) individually or in bulk
• Hash Generator — Generate MD5, SHA-1, SHA-256, SHA-512 hashes
• Regex Tester — Test and debug regular expressions with real-time match highlighting
• Timestamp Converter — Convert between Unix timestamps and human-readable dates
• Alternative Timestamps Converter — Convert Unix timestamps (seconds, ms, µs, ns) to readable dates, with LDAP, WebKit, NTP and Cocoa epoch offsets explained
• Color Picker & Converter — Pick colors and convert between HEX, RGB and HSL formats
• SQL Formatter — Format and beautify SQL queries with keyword highlighting
• Diff Checker & Merge — Compare two texts or code files side by side, then merge changes line by line
• Password Generator — Generate strong, secure passwords with custom rules
• Lorem Ipsum Generator — Generate Lorem Ipsum placeholder text of any length
• Gradient Generator — Create CSS gradients visually and copy the CSS code
• Cron Expression Builder — Build and validate cron expressions with human-readable descriptions
• Markdown Preview — Write and preview Markdown with live rendering
• HTML Entity Encoder/Decoder — Escape or unescape HTML entities safely in your browser
• JSON ⇄ CSV Converter — Convert JSON arrays to CSV and CSV back to JSON, with nested-key flattening
• Chmod Calculator — Build Unix file permissions visually — octal, symbolic and command output
• URL Parser — Break a URL into protocol, host, path, query params and hash
• JSON to TOON Converter — Convert JSON to TOON (Token-Oriented Object Notation) and back — cut LLM prompt tokens
• JSON Compare — Compare two JSON documents — ignores key order, lists every changed path, merge side by side

Why use Toolskyt Developer

• Instant Local Formatting — Parse, validate, and pretty-print raw JSON, SQL, or XML configurations instantly without lag.
• Secured Cryptography — Generate hashes (MD5, SHA-256) and cryptographically secure passwords completely offline.
• Zero Leak Guarantee — Never paste sensitive configuration strings, JWT tokens, or credentials into public APIs. Everything runs locally.

Frequently asked questions

Is it safe to paste JWT tokens or API configs here?

Yes. Unlike online tools that send payload data to backend servers, Toolskyt parses and formats all tokens and files inside your browser. No data ever leaves your device.

Does the JSON Formatter validate syntax errors?

Yes, our JSON formatter highlights exact syntax errors, missing commas, or unmatched brackets in real-time, helping you debug raw configurations.

Can I use these tools without an internet connection?

Yes, once loaded, all developer utilities operate fully offline. You can test regex, decode Base64, and generate passwords anywhere.