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 ↓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.
Regex tester and replacerTest regular expressions, inspect matches and preview replacements locally in your browser.100% local→SHA hash generatorCalculate SHA-1, SHA-256, SHA-384 and SHA-512 hashes for text or files with Web Crypto.100% local→SimplePostmanA reduced HTTP client to build requests, generate cURL and inspect responses in the browser.External API→UUID and random key generatorGenerate UUID v4 values and random strings with Web Crypto, fully local in the browser.100% local→Password and passphrase generatorCreate passwords and secure passphrases without storing data or making network calls.100% local→YAML formatter and validatorValidate, format and convert YAML and JSON locally in your browser.100% local→Base64 encoder & decoderEncode plain text to Base64 and decode it locally in your browser.100% local→HTML/CSS/JS formatterFormat and minify code snippets locally.100% local→CSV parser & converterPreview CSV and convert it to JSON, Markdown or HTML.100% local→cURL builderGenerate HTTP requests and code snippets.100% local→CSS color converterConvert HEX, RGB, HSL, HWB and CSS color names.100% local→Visual text diff checkerCompare two texts locally with line and word-level visual differences.100% local→JSON viewer & formatterView, validate and format JSON locally.100% local→JWT decoderDecode JWT tokens locally in your browser.100% local→MD5 generatorGenerate MD5 hashes in the browser.100% local→SQL formatterFormat, minify and export SQL queries locally.100% local→Timestamp & timezone converterConvert Unix timestamps, ISO dates and time zones.100% local→URL encoder & decoderEncode URLs and query parameters.100% local→URL inspectorAnalyze URLs for developers.100% local→XML formatter & validatorFormat, validate and minify XML locally.100% local→HTML entity encoder and decoderEncode reserved HTML characters or decode entities locally.100% local→JSON to TypeScript converterGenerate readable TypeScript interfaces from JSON objects and arrays.100% local→Number base converterConvert integers between binary, octal, decimal and hexadecimal.100% local→Unix chmod calculatorBuild Unix file permissions visually and copy numeric or symbolic values.100% local→Cron expression builderBuild standard five-field cron expressions from readable schedule controls.100% local→Text to binaryText to binary locally in your browser, with a clear result you can copy.100% local→Binary to textBinary to text locally in your browser, with a clear result you can copy.100% local→JSON to CSVJSON to CSV locally in your browser, with a clear result you can copy.100% local→JSON path extractorJSON path extractor locally in your browser, with a clear result you can copy.100% local→Query string parserQuery string parser locally in your browser, with a clear result you can copy.100% local→Query string builderQuery string builder locally in your browser, with a clear result you can copy.100% local→Unicode escape converterUnicode escape converter locally in your browser, with a clear result you can copy.100% local→ASCII table lookupASCII table lookup locally in your browser, with a clear result you can copy.100% local→Hex to textHex to text locally in your browser, with a clear result you can copy.100% local→Text to hexText to hex locally in your browser, with a clear result you can copy.100% local→HTTP status lookupHTTP status lookup locally in your browser, with a clear result you can copy.100% local→MIME type lookupMIME type lookup locally in your browser, with a clear result you can copy.100% local→Port number lookupPort number lookup locally in your browser, with a clear result you can copy.100% local→User-agent parserUser-agent parser locally in your browser, with a clear result you can copy.100% local→Gitignore generatorGitignore generator locally in your browser, with a clear result you can copy.100% local→Docker run builderDocker run builder locally in your browser, with a clear result you can copy.100% local→SSH command builderSSH command builder locally in your browser, with a clear result you can copy.100% local→Regex escape toolRegex escape tool locally in your browser, with a clear result you can copy.100% local→Regex flags explainerRegex flags explainer locally in your browser, with a clear result you can copy.100% local→JSON key sorterJSON key sorter locally in your browser, with a clear result you can copy.100% local→JSON flattenerJSON flattener locally in your browser, with a clear result you can copy.100% local→JSON unflattenerJSON unflattener locally in your browser, with a clear result you can copy.100% local→JSON Schema generatorJSON Schema generator locally in your browser, with a clear result you can copy.100% local→XML escape and unescapeXML escape and unescape locally in your browser, with a clear result you can copy.100% local→SQL IN list builderSQL IN list builder locally in your browser, with a clear result you can copy.100% local→Environment variable parserEnvironment variable parser locally in your browser, with a clear result you can copy.100% local→INI to JSON converterINI to JSON converter locally in your browser, with a clear result you can copy.100% local→Semantic version comparatorSemantic version comparator locally in your browser, with a clear result you can copy.100% local→Semantic version bumperSemantic version bumper locally in your browser, with a clear result you can copy.100% local→Color contrast checkerColor contrast checker locally in your browser, with a clear result you can copy.100% local→CSS clamp calculatorCSS clamp calculator locally in your browser, with a clear result you can copy.100% local→Text data URI generatorText data URI generator locally in your browser, with a clear result you can copy.100% local→Checksum comparatorChecksum comparator locally in your browser, with a clear result you can copy.100% local→Random test data generatorRandom test data generator locally in your browser, with a clear result you can copy.100% local→Fake user generatorFake user generator locally in your browser, with a clear result you can copy.100% local→API response mockerAPI response mocker locally in your browser, with a clear result you can copy.100% local→GraphQL query minifierGraphQL query minifier locally in your browser, with a clear result you can copy.100% local→ULID generatorULID generator instantly and privately in your browser.100% local→Nano ID generatorNano ID generator instantly and privately in your browser.100% local→One-time code generatorOne-time code generator instantly and privately in your browser.100% local→Random PIN generatorRandom PIN generator instantly and privately in your browser.100% local→Random HEX color generatorRandom HEX color generator instantly and privately in your browser.100% local→CSS gradient generatorCSS gradient generator instantly and privately in your browser.100% local→CSS shadow generatorCSS shadow generator instantly and privately in your browser.100% local→Border radius generatorBorder radius generator instantly and privately in your browser.100% local→CSS grid generatorCSS grid generator instantly and privately in your browser.100% local→Flexbox CSS generatorFlexbox CSS generator instantly and privately in your browser.100% local→Media query generatorMedia query generator instantly and privately in your browser.100% local→Placeholder avatar SVGPlaceholder avatar SVG instantly and privately in your browser.100% local→Initials avatar SVGInitials avatar SVG instantly and privately in your browser.100% local→SVG pattern generatorSVG pattern generator instantly and privately in your browser.100% local→SVG blob generatorSVG blob generator instantly and privately in your browser.100% local→SVG wave generatorSVG wave generator instantly and privately in your browser.100% local→Chart data generatorChart data generator instantly and privately in your browser.100% local→CSV test data generatorCSV test data generator instantly and privately in your browser.100% local→Code placeholder generatorCode placeholder generator instantly and privately in your browser.100% local→Git branch name generatorGit branch name generator instantly and privately in your browser.100% local→Commit message helperCommit message helper instantly and privately in your browser.100% local→Package name generatorPackage name generator instantly and privately in your browser.100% local→Docker Compose generatorDocker Compose generator instantly and privately in your browser.100% local→Nginx redirect generatorNginx redirect generator instantly and privately in your browser.100% local→.htaccess redirect generator.htaccess redirect generator instantly and privately in your browser.100% local→Content Security Policy builderContent Security Policy builder instantly and privately in your browser.100% local→Permissions Policy builderPermissions Policy builder instantly and privately in your browser.100% local→Cache-Control builderCache-Control builder instantly and privately in your browser.100% local→CORS header builderCORS header builder instantly and privately in your browser.100% local→Cron expression explainerCron expression explainer instantly and privately in your browser.100% local→Unix signal referenceUnix signal reference instantly and privately in your browser.100% local→Keyboard key referenceKeyboard key reference instantly and privately in your browser.100% local→CSS easing referenceCSS easing reference instantly and privately in your browser.100% local→HTML doctype generatorHTML doctype generator instantly and privately in your browser.100% local→Regex cheatsheetRegex cheatsheet instantly and privately in your browser.100% local→HTTP header referenceHTTP header reference instantly and privately in your browser.100% local→Country code lookupCountry code lookup instantly and privately in your browser.100% local→Language code lookupLanguage code lookup instantly and privately in your browser.100% local→Timezone finderTimezone finder instantly and privately in your browser.100% local→File signature referenceFile signature reference instantly and privately in your browser.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.