Free Developer Tools — Base64, SQL, Regex, JSON & More
Developer utilities for encoding, formatting, converting, and testing. All client-side, no signup required.
Percentage Difference Calculator
Calculate percentage increase or decrease between two values instantly. Color-coded results — green for increase, red for decrease. Shows formula with your numbers. Free, no signup.
Use Tool →UUID Generator
Generate random UUID v4 values in bulk — up to 500 at once. Uppercase or lowercase, with or without hyphens. Copy all or download as .txt. Cryptographically secure, client-side only.
Use Tool →Base64 Encoder & Decoder
Encode text or images to Base64 strings — or decode Base64 back to text. Supports file upload for image encoding. All processing is done in your browser. Free, no signup.
Use Tool →SQL Formatter & Beautifier
Format and beautify SQL queries instantly. Supports MySQL, PostgreSQL, SQL Server, and generic SQL. Uppercase keywords, minify option, dark mode output. Free, no signup.
Use Tool →HTML Entity Encoder
Encode or decode HTML entities and special characters in real time. Includes a reference table of common entities. Free, no signup.
Use Tool →Text Diff Checker
Compare two blocks of text and highlight differences instantly. Shows additions in green, deletions in red. Line-by-line and word-by-word modes. Free diff checker, no signup.
Use Tool →Number Base Converter
Convert between binary, octal, decimal, and hexadecimal instantly. Shows all four bases simultaneously with one-click copy buttons. Free, no signup.
Use Tool →Markdown to HTML Converter
Convert Markdown to HTML with a live rendered preview. Supports headings, bold, italic, lists, links, code blocks, tables, and blockquotes. Copy raw HTML instantly. Free, no signup.
Use Tool →JSON to CSV Converter
Convert JSON arrays to CSV format instantly. Supports comma, semicolon, and tab delimiters. Download as .csv. Free JSON to CSV converter, no signup.
Use Tool →CSV to JSON Converter
Convert CSV files to JSON arrays instantly. Auto-detects delimiter. Download as .json. Free CSV to JSON converter, no signup required.
Use Tool →RegEx Tester
Test and debug regular expressions with live match highlighting. Includes common pattern library for email, URL, phone, and more. Free regex tester, no signup.
Use Tool →Crontab Generator
Generate cron expressions with a visual UI. See human-readable description and next 5 run times. Includes common presets. Free crontab generator, no signup.
Use Tool →HTML Table Generator
Generate HTML table code with editable cells up to 20x20. Supports headers, borders, Bootstrap striped rows, and responsive wrapper. Free, no signup.
Use Tool →IP Subnet Calculator
Calculate network address, broadcast address, subnet mask, wildcard mask, and host range for any IPv4/CIDR. Shows binary representation and IP class. Free, no signup.
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