Alon Tools
25 tools · Development

Online developer tools

Work with JSON, XML, YAML, SQL, hashes, regular expressions, JWTs and HTTP requests without installing software. Most operations run locally to keep your data private.

Browse tools ↓
01Format and validate structured data
02Generate hashes, UUIDs and secure keys
03Test APIs, regex and cron expressions
No accounts or friction

All development tools

Open any utility and start working. Each card tells you whether processing is local or requires a public API.

REGEXRegex tester and replacerTest regular expressions, inspect matches and preview replacements locally in your browser.100% localHASHSHA hash generatorCalculate SHA-1, SHA-256, SHA-384 and SHA-512 hashes for text or files with Web Crypto.100% localHTTPSimplePostmanA reduced HTTP client to build requests, generate cURL and inspect responses in the browser.External APIUUIDUUID and random key generatorGenerate UUID v4 values and random strings with Web Crypto, fully local in the browser.100% localPASSPassword and passphrase generatorCreate passwords and secure passphrases without storing data or making network calls.100% localYAMLYAML formatter and validatorValidate, format and convert YAML and JSON locally in your browser.100% local64Base64 encoder & decoderEncode plain text to Base64 and decode it locally in your browser.100% localCODEHTML/CSS/JS formatterFormat and minify code snippets locally.100% localCSVCSV parser & converterPreview CSV and convert it to JSON, Markdown or HTML.100% localAPIcURL builderGenerate HTTP requests and code snippets.100% localCOLORCSS color converterConvert HEX, RGB, HSL, HWB and CSS color names.100% localDIFFVisual text diff checkerCompare two texts locally with line and word-level visual differences.100% local{}JSON viewer & formatterView, validate and format JSON locally.100% localJWTJWT decoderDecode JWT tokens locally in your browser.100% localMD5MD5 generatorGenerate MD5 hashes in the browser.100% localSQLSQL formatterFormat, minify and export SQL queries locally.100% localTIMETimestamp & timezone converterConvert Unix timestamps, ISO dates and time zones.100% localENCURL encoder & decoderEncode URLs and query parameters.100% localURLURL inspectorAnalyze URLs for developers.100% localXMLXML formatter & validatorFormat, validate and minify XML locally.100% local&;HTML entity encoder and decoderEncode reserved HTML characters or decode entities locally.100% localTSJSON to TypeScript converterGenerate readable TypeScript interfaces from JSON objects and arrays.100% localBASENumber base converterConvert integers between binary, octal, decimal and hexadecimal.100% local755Unix chmod calculatorBuild Unix file permissions visually and copy numeric or symbolic values.100% localCRONCron expression builderBuild standard five-field cron expressions from readable schedule controls.100% local

Simple tools for real tasks

Free utilities to format, validate, convert and test code, APIs and data directly in your browser.

Each tool focuses on one task, with a visible primary action, useful examples and results you can copy or download. There are no unnecessary dashboards or registration flows.

Frequently asked questions

Are these tools free?

Yes. You can use them without creating an account or artificial usage limits.

Are my data or files uploaded?

Tools marked 100% local process everything in your browser. If a utility needs an external API, it is clearly identified before you open it.

Do they work on mobile and in dark mode?

Yes. The interface is mobile first, keyboard accessible and supports both light and dark modes.