Free Online Developer Tools and Formatters
Most of these tools exist for one particular moment: something came back from an API and it does not look right. Formatters and validators for JSON, YAML and XML, converters between them, a diff, a regex tester, base64, cURL translation, a JWT decoder. That last one is worth calling out — the token is decoded by JavaScript on your machine and never transmitted, which matters when the token on your clipboard is a live one.
Tools in this category
- JSON Formatter Format and beautify your JSON data with proper indentation.
- JSON Validator Validate your JSON data and get detailed error messages.
- Base64 Encoder/Decoder Encode text to Base64 or decode Base64 back to plain text.
- URL Encoder/Decoder Percent-encode text for URLs or decode encoded URL components.
- JWT Decoder Decode and inspect the header and payload of a JWT token.
- JSON Minifier Minify and compress JSON to the smallest possible size.
- JSON Diff Compare two JSON documents and see exactly what changed.
- JSON to CSV Convert a JSON array of objects into CSV for Excel or Sheets.
- JSON to YAML Convert JSON into clean, readable YAML for config files.
- JSON to XML Convert JSON into well-formed, indented XML in one click.
- JSON to TypeScript Generate TypeScript interfaces from a JSON sample instantly.
- JSON to JavaScript Convert JSON into a clean JavaScript object literal.
- JSON to Table Turn a JSON array of objects into an HTML table.
- JSON Flattener Flatten nested JSON into single-level dot-notation keys.
- JSON Unflattener Rebuild nested JSON from flat dot-notation keys.
- JSON Escape Escape text so it can be used safely as a JSON string.
- JSON Unescape Turn an escaped JSON string back into plain text.
- JSON Sort Keys Alphabetically sort the keys of a JSON object, recursively.
- JSON Path Tester Test JSONPath expressions against JSON and see the matches.
- CSV to JSON Convert CSV into a JSON array of objects with type parsing.
- CSV to YAML Convert CSV into a clean YAML list of mappings.
- CSV to Markdown Convert CSV into an aligned Markdown table for GitHub and docs.
- CSV Viewer View CSV as a searchable, sortable table in your browser.
- CSV Column Extractor Keep or reorder only the CSV columns you choose by name.
- CSV Delimiter Converter Change a CSV delimiter between comma, semicolon, and tab.
- XML Formatter Format, beautify, and minify XML with one click.
- XML Validator Check whether XML is well-formed and pinpoint errors.
- XML to JSON Convert XML into structured JSON with attributes and arrays.
- YAML Formatter Clean up and re-indent YAML with consistent formatting.
- YAML Validator Check whether YAML is well-formed and pinpoint syntax errors.
- YAML to JSON Convert YAML into clean, structured JSON instantly.
- HTML Encoder/Decoder Encode special characters to HTML entities or decode HTML entities back to text.
- Unicode Encoder/Decoder Encode text to \uXXXX Unicode escape sequences or decode escapes back to text.
- ASCII Converter Convert text to ASCII codes and ASCII codes back to text.
- Hex Encoder Encode text to hexadecimal and decode hex back to text.
- Hex Decoder Decode a hexadecimal string back into readable text.
- Binary Converter Convert text to binary and binary back to text.
- UUID Generator Generate random RFC 4122 UUIDs (v4) instantly in your browser.
- Bcrypt Generator Generate and verify bcrypt password hashes online, right in your browser.
- SHA-256 Generator Generate a SHA-256 hash from any text online, right in your browser.
- SHA-1 Generator Generate a SHA-1 hash from any text online, right in your browser.
- MD5 Generator Generate an MD5 hash from any text online, right in your browser.
- Timestamp Converter Convert Unix timestamps to human-readable dates and back, in your browser.
- Unix Time Converter Convert Unix time (epoch) to a human date and back, with a live current epoch clock.
- Cron Expression Generator Build and understand cron schedule expressions with presets and a plain-English description.
- Cron Expression Parser Paste a cron expression and instantly read what it means in plain English, with a field-by-field breakdown.
- Regex Tester Test and debug regular expressions against your text, with live matches and capture groups.
- Regex Escape Escape special regex characters so any text can be matched literally, or unescape them back.
- Markdown Preview Write Markdown and see the rendered HTML update live in your browser.
- Markdown to HTML Convert Markdown to clean HTML source code you can copy or download.
- HTML to Markdown Convert HTML into clean Markdown you can copy or download.
- Diff Checker Compare two blocks of text and see added and removed lines.
- Text Compare Compare two texts side by side and find the differences with word-level highlighting.
- SQL Formatter Format, beautify, and minify SQL queries with clean indentation.
- SQL Minifier Minify and compress SQL queries by removing whitespace and comments.
- JWT Generator Create and sign a JSON Web Token (JWT) with HS256, HS384, or HS512.
- User Agent Parser Parse a User-Agent string into browser, engine, operating system, and device.