Free developer tools.$ devtools --no-upload --instant
22 client-side developer utilities. Everything runs in your browser.
tools=22categories=5
zshnodegit
term ── ~/makemydev ── 80×24
$ mmd json --format < sample.json
{ "user": "ada", "id": 7 }
$ mmd uuid --v7
01936a2f-4c1e-7b8e-a1d9-8e4c2fc091a3
$ mmd base64 --decode 'SGVsbG8h'
Hello!
$ mmd regex --test
555-1234 match[0]="555-1234"
abc-1234 no match
$
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Tools — 22 total · 5 categories
grouped by categoryFormattersPretty-print and minify.§01 · 3 tools
- JSON FormatterFormat, validate, and minify JSON with syntax highlighting and error reporting.Formatters
- SQL FormatterPretty-print or minify SQL queries with tunable keyword case, indent, and comma placement. Works across Postgres, MySQL, and SQL Server.Formatters
- HTML / CSS / JS FormatterBeautify or minify HTML, CSS, and JavaScript in your browser. Configurable indentation, nothing uploaded.Formatters
EncodersText ↔ Base64, URL, HTML.§02 · 3 tools
TestersDiff, regex, JWT, syntax.§05 · 4 tools
- Diff CheckerCompare two blocks of text side by side with color-coded additions and removals.Testers
- Regex TesterTest regular expressions with live match highlighting, capture groups, and a cheatsheet.Testers
- JWT DecoderDecode JWT tokens to inspect the header, payload, and expiry status.Testers
- Syntax CheckerValidate syntax for JSON, YAML, JavaScript, HTML, CSS, and SQL.Testers
GeneratorsUUIDs, cron, hashes, passwords.§03 · 7 tools
- UUID GeneratorGenerate RFC 4122 v4 and v7 UUIDs in bulk with one-click copy.Generators
- Cron Expression BuilderBuild and parse cron expressions with a visual editor and next-run preview.Generators
- Test Card GeneratorGenerate Luhn-valid test credit card numbers for Visa, Mastercard, Amex, and Discover.Generators
- QR Code GeneratorGenerate QR codes for text, URLs, WiFi credentials, and vCards. Download as PNG.Generators
- Hash GeneratorGenerate MD5, SHA-1, SHA-256, SHA-384, and SHA-512 hashes from text or files.Generators
- Lorem Ipsum GeneratorGenerate placeholder text by paragraphs, sentences, words, or UTF-8 byte budget.Generators
- Password GeneratorGenerate crypto-secure random passwords or diceware-style passphrases with tunable length and character classes.Generators
ConvertersBetween formats and shapes.§04 · 5 tools
- YAML ↔ JSON ConverterConvert between YAML and JSON formats with syntax highlighting.Converters
- Timestamp ConverterConvert between Unix timestamps, ISO 8601, and human-readable dates across timezones.Converters
- Color ConverterConvert colors between HEX, RGB, HSL, and OKLCH with alpha support and WCAG contrast checks.Converters
- Text Case ConverterConvert identifiers and prose between camelCase, snake_case, kebab-case, Title Case, SCREAMING_SNAKE, and more.Converters
- JSON to TypeScriptConvert any JSON sample into TypeScript interfaces or type aliases with inferred optional fields and nested types.Converters