43 tools
Developer Tools
Format, validate and convert code and data.
Base64 Decoder
Decode Base64 back to readable text.
Base64 Encoder
Encode text or UTF-8 data as Base64, including URL-safe output.
Caesar Cipher and ROT13
Shift letters to encode or decode a Caesar cipher.
Chmod Calculator
Convert Unix permissions between 755 and rwxr-xr-x.
Cron Expression Explainer
Understand a cron schedule and see its next runs.
CSS Formatter
Expand compressed CSS into readable rules.
CSS Minifier
Shrink stylesheets by removing comments and whitespace.
CSV to JSON Converter
Convert CSV rows into structured JSON, with type detection.
CSV to Markdown Table
Turn spreadsheet data into a Markdown table.
Hash Generator (SHA-256, SHA-1, SHA-512)
Compute SHA checksums of text in your browser.
HMAC Generator
Sign a message with a secret key using HMAC-SHA256.
HTML Entity Encoder / Decoder
Escape and unescape HTML entities in both directions.
HTML Formatter
Indent nested HTML and make long templates readable.
HTML Minifier
Remove comments and redundant whitespace from HTML.
HTML to Markdown Converter
Convert HTML into clean Markdown.
IP Subnet Calculator (CIDR)
Network, broadcast, mask and host range of an IPv4 subnet.
JavaScript Minifier
Strip comments and blank lines from JavaScript safely.
JSON Formatter
Pretty-print compact or broken JSON with a readable indentation.
JSON Minifier
Strip whitespace from JSON to shrink payloads.
JSON String Escape and Unescape
Escape text for a JSON string, or read an escaped one.
JSON to CSV Converter
Turn an array of JSON objects into a spreadsheet-ready CSV.
JSON to TypeScript Interface Generator
Generate TypeScript interfaces from a JSON sample.
JSON to YAML Converter
Turn JSON into readable YAML for configuration files.
JSON Validator
Check JSON syntax and see exactly where it breaks.
JWT Decoder
Inspect the header and claims of a JSON Web Token.
Markdown Previewer
Write Markdown and see clean, sanitised HTML.
Number Base Converter
Convert between binary, octal, decimal and hexadecimal.
Password Generator
Strong passwords with a live entropy estimate.
Password Strength Checker
Estimate how long a password would resist guessing.
Random String Generator
Create random tokens, codes and IDs with a custom alphabet.
Regex Tester
Test patterns against sample text with live match highlighting.
SQL Formatter
Format SQL queries with consistent keywords and indentation.
Text Diff Checker
Compare two texts line by line and see what changed.
Text to Binary Converter
Convert text to binary, hex or decimal bytes and back.
Unix Timestamp Converter
Convert epoch seconds and milliseconds to dates and back.
URL Decoder
Turn percent-encoded URLs back into readable text.
URL Encoder
Percent-encode text for URLs and query strings.
URL Parser
Break a URL into protocol, host, path and query parameters.
User Agent Parser
Identify the browser, OS and device from a user agent.
UUID Generator
Generate cryptographically random UUID v4 and time-ordered v7.
XML Formatter
Indent XML documents while preserving their content.
XML Validator
Find unclosed tags and malformed markup.
YAML to JSON Converter
Convert a YAML document into JSON.
About Developer Tools
Everyday utilities for people who write code: JSON and XML formatting, minification, encoding, UUIDs, timestamps and parsing helpers. Most run entirely in your browser, so source code never leaves your machine.
Every tool on this page is free and requires no account. Where a tool can run entirely in the browser, it does: your input is not sent to a server, and no copy is stored.