Developer tools
Free developer tools from NibCat. Open a tool, use it in your browser, and read the practical notes below each tool.
URL Encoder / Decoder
Encode or decode URLs online for free. Instantly percent-encode special characters or decode %XX sequences in your browser — no data sent to servers.
JSON Formatter & Validator
Format, validate, and minify JSON instantly in your browser. Paste messy JSON and get beautifully indented output with error highlighting. No data sent to servers.
IP Address & Network Info
Check your current IPv4/IPv6 addresses, reverse DNS, location, ISP, ASN, TLS, and browser/device info.
Base64 Encoder / Decoder
Encode text or files to Base64, or decode Base64 strings back to text. Supports data URI output. All processing in your browser.
Regex Tester
Test JavaScript regular expressions in real time with match highlighting, g/i/m/s flags, capture details, and common presets.
Unix Timestamp Converter
Convert Unix timestamps to readable dates, convert dates back to Unix time, and copy the current Unix timestamp. Supports seconds, milliseconds, UTC, and local time.
chmod Calculator
Visualize Unix and Linux chmod permissions like 755, 644, and 600. Understand owner, group, others, rwx notation, and risky writable settings.