Free Developer tools
Inspect structured data, translate encodings, test a pattern or prepare compact source files. All 15 developer tools process input locally, with examples and syntax checks where applicable.
Choose from all developer tools
JSON Formatter & Validator
Validate, format, or minify JSON with helpful error feedback.
Open tool →Base64 Encoder/Decoder
Encode Unicode text as Base64 or decode it back to text.
Open tool →URL Encoder/Decoder
Safely encode or decode a URL component.
Open tool →JSON to CSV Converter
Turn JSON objects into properly escaped CSV, with spreadsheet formula protection and a local download.
Open tool →CSV to JSON Converter
Convert quoted CSV rows into readable JSON while preserving empty cells, Unicode, and leading zeros.
Open tool →HTML Encoder/Decoder
Encode special HTML characters or decode named and numeric entities safely as plain text.
Open tool →JWT Decoder
Read a JWT header, payload, signature section, and claim timestamps locally without claiming verification.
Open tool →UUID Generator
Generate secure random UUID v4 identifiers in batches, then copy individual values or download the list.
Open tool →Regex Tester
Test JavaScript regular expressions with highlighted matches, positions, and capturing groups in a time-limited worker.
Open tool →Unix Timestamp Converter
Convert seconds or milliseconds to UTC, local time, and ISO dates, or turn a date into a timestamp.
Open tool →Color Converter
Preview a color and convert HEX, RGB, HSL, and alpha formats with individual copy controls.
Open tool →Markdown Previewer
Write Markdown with a live, sanitized preview of headings, lists, links, code blocks, and tables.
Open tool →HTML Minifier
Reduce HTML comments and tag formatting conservatively while preserving meaningful text spacing.
Open tool →CSS Minifier
Remove CSS formatting with a real parser while preserving rule order and custom property values.
Open tool →JavaScript Minifier
Minify modern JavaScript locally with Terser, without executing code or renaming your variables.
Open tool →Match the tool to your data format
JSON Formatter checks JSON syntax. JSON-to-CSV and CSV-to-JSON turn records into rows and back, with explicit headers. Base64 handles UTF-8 text, while URL encoding escapes one URL component. The minifiers parse source without running it.
Before you start
JWT decoding does not verify a signature. Regex runs with a time limit. Markdown preview removes unsafe HTML. Formatting JSON uses JavaScript number precision; keep exact large identifiers as strings.