Free Online Developer Tools
Formatters, encoders, converters, generators and playgrounds for everyday development work. Your code and data stay in your browser.
JSON FormatterValidate, pretty-print, minify and sort JSONJSON ValidatorCheck JSON syntax and find the exact error lineJSON MinifierCompress JSON by removing all whitespaceBase64 Encode/DecodeText, files and images to and from Base64Base64 EncoderConvert text to Base64, UTF-8 safeBase64 DecoderDecode Base64 to readable textImage to Base64Convert images to Base64 data URIsBase64 to ImageDecode Base64 or a data URI to an image fileURL Encoder & ParserEncode, decode and break down URLs and query stringsURL DecoderDecode %20 and other percent-encoded URLsURL ParserSplit a URL into parts and list its query parametersJWT DecoderDecode JWT header and claims, check expiry, verify signatureJWT GeneratorCreate and sign HS256/384/512 JSON Web TokensUUID & ID GeneratorUUID v4/v7, ULID and Nano ID in bulk, plus inspectorUUID v4 GeneratorRandom version 4 UUIDs, one or thousandsUUID v7 GeneratorTime-ordered UUIDs for database keys (RFC 9562)GUID GeneratorRandom GUIDs for .NET, SQL Server and WindowsULID GeneratorSortable 26-character ULIDs with timestamp decoderNano ID GeneratorShort, URL-safe random IDs of any lengthHash GeneratorMD5, SHA-1, SHA-256, SHA-512 and CRC32 for text and filesMD5 Hash GeneratorMD5 hash of any text or fileSHA-1 Hash GeneratorSHA-1 hash of text or filesSHA-256 Hash GeneratorSHA-256 hash and checksum of text or filesSHA-512 Hash GeneratorSHA-512 and SHA-384 hashes of text or filesHMAC GeneratorHMAC-SHA256, SHA-512, SHA-1 and MD5 with a secret keyFile Checksum CalculatorVerify a download with SHA-256, SHA-1 or MD5CRC32 Checksum CalculatorCRC-32 of text or files (ZIP, PNG, Ethernet)Regex TesterLive match highlighting, capture groups and replaceDiff CheckerCompare two texts line by line and word by wordUnix Timestamp ConverterEpoch time to dates and back, in any time zoneCurrent Unix TimestampThe current epoch time in seconds and milliseconds, liveEpoch to Date ConverterTurn a Unix timestamp into a readable date and timeEpoch Milliseconds ConverterConvert JavaScript millisecond timestamps to datesCron Expression ExplainerExplain cron schedules in plain English and list next runsCrontab GeneratorBuild a cron schedule with menus, no syntax neededChmod CalculatorUnix permissions between octal, rwx and checkboxesJSON ⇄ CSV ConverterConvert between JSON arrays and CSV tablesCSV to JSON ConverterTurn CSV or spreadsheet exports into JSONJSON to CSV ConverterTurn a JSON array into a CSV for Excel or SheetsYAML ⇄ JSON ConverterConvert YAML and JSON both ways with error linesYAML to JSON ConverterConvert YAML config files to JSONJSON to YAML ConverterConvert JSON to clean, readable YAMLJSON to TypesGenerate TypeScript, Go, Python, Rust and C# types from JSONJSON to TypeScriptGenerate TypeScript interfaces from JSONJSON to Go StructGenerate Go structs with json tags from JSONJSON to Python ClassGenerate Python dataclasses or Pydantic models from JSONJSON Schema GeneratorInfer a JSON Schema from a sample documentSubnet CalculatorIPv4 CIDR ranges, masks, host counts and subnettingHTML/CSS/JS PlaygroundLive front-end sandbox with preview and consoleSQL PlaygroundA real SQLite database in your browser; import CSVPython RunnerRun Python 3 in the browser, with NumPy and pandasMarkdown PreviewWrite Markdown with live preview, export HTMLMarkdown to HTML ConverterConvert Markdown to clean, safe HTMLCode MinifierMinify CSS, JavaScript, HTML and JSONCSS MinifierCompress CSS by removing comments and whitespaceJavaScript MinifierMinify and compress JavaScript with TerserHTML MinifierCompress HTML while keeping pre and script blocksHTTP Status CodesSearchable reference of HTTP status codesHTML Entity EncoderEncode and decode HTML entities, with a symbol referenceString Escape & UnescapeEscape strings for JSON, JS, Python, SQL, CSV, regex, shellJSON Escape & UnescapeEscape text as a JSON string, or unescape \n and \"Code BeautifierFormat minified CSS, HTML and JavaScriptCSS FormatterBeautify minified CSS into readable rulesHTML FormatterIndent and beautify HTML markupJavaScript FormatterBeautify minified JavaScript codeXML FormatterValidate, pretty-print and minify XML, with XPathSQL FormatterBeautify SQL queries with clause-per-line layout.gitignore GeneratorBuild a .gitignore for your languages, OS and editorcurl to Code ConverterConvert curl commands to fetch, axios, Python, Go, PHPJSONPath TesterQuery JSON with JSONPath expressions, liveUser Agent ParserIdentify browser, OS, device and bots from a User-AgentMIME Type LookupFind the MIME type for any file extension, or detect a fileJavaScript Key Code FinderPress a key to see event.key, code and keyCodeNumber FormatterFormat numbers and currencies for any locale with IntlText to Binary ConverterText to binary, hex, octal and decimal bytes and backBinary to Text ConverterDecode binary 0s and 1s into readable textText to Hex ConverterConvert text to hexadecimal bytes and backHTML to Markdown ConverterConvert HTML or copied web content into MarkdownXML ⇄ JSON ConverterConvert XML to JSON and JSON to XMLXML to JSON ConverterTurn XML documents into JSONJSON to XML ConverterTurn JSON into well-formed XMLJSON DiffCompare two JSON documents by structure, not textMermaid Diagram EditorFlowcharts, sequence, Gantt and ER diagrams from textFlowchart MakerMake flowcharts from simple text and export PNG or SVGCode to ImageTurn code into a beautiful, shareable PNGBarcode GeneratorCode 128, EAN-13, UPC-A and EAN-8 barcodes as PNG or SVGEAN-13 Barcode GeneratorCreate EAN-13 product barcodes with check digitDiscord Timestamp GeneratorMake <t:…> timestamps that show in everyone’s time zoneMarkdown Table GeneratorBuild Markdown tables visually or from CSVDummy File GeneratorCreate test files of an exact size: 1 MB, 10 MB, 1 GB…Fake Data GeneratorMock test data as JSON, CSV or SQL: names, emails, orders…