Developer Tools
JSON formatting, encoding, and other small utilities developers reach for dozens of times a week — fast, offline-capable, and copy-paste friendly.
JSON Formatter
Format, validate, and beautify JSON instantly with clear error messages when something's wrong. Runs entirely client-side.
Base64 Encoder/Decoder
Encode plain text to Base64 or decode Base64 back to plain text, entirely in your browser.
URL Encoder/Decoder
Encode special characters for safe use in URLs, or decode a percent-encoded URL back to readable text.
UUID Generator
Generate one or many random version-4 UUIDs for use as unique identifiers in code, databases, or testing.
Markdown Previewer
Write Markdown and see a live rendered preview side by side, with HTML you can copy out.
Regex Tester
Test a regular expression against sample text with live match highlighting and flag support.
Timestamp Converter
Convert a Unix timestamp to a human-readable date, or a date to a Unix timestamp, with the current time shown live.
HTML Entity Encoder/Decoder
Encode special characters into HTML entities, or decode HTML entities back into plain text.
Cron Expression Explainer
Paste a 5-field cron expression and get a plain-English explanation of when it runs.
AI Prompt Token Counter
Estimate how many tokens a prompt will use and check it against common model context limits.
Meta Tag Generator
Generate title, description, Open Graph, and Twitter Card meta tags with a live social preview.
Mock JSON Data Generator
Generate realistic-looking fake JSON records for testing, prototyping, or populating a demo UI.
JWT Decoder
Decode a JSON Web Token's header and payload to inspect its contents, without verifying the signature.
IP Subnet Calculator
Calculate network address, broadcast address, subnet mask, and usable host range from an IP and CIDR prefix.
CSS Formatter
Beautify messy CSS into readable, indented code, or minify it down for production.