Developer and data
The everyday desk tools: formatting, encoding, identifiers, networks.
Formatters, encoders, identifiers and network arithmetic: the small jobs a desk needs a dozen times a day. Each one keeps what other tools drop, long numbers, key order, emoji inside base64, and when a document is wrong it says where and why rather than only that it is.
JSON DiffCompare two documents structurallyXML FormatterIndent and check in the same momentSubnet CalculatorCIDR, masks, host ranges and splittingBase64 Encoder & DecoderEncode or decode, the direction is detectedUUID Generatorv4 and time-ordered v7, plus an inspectorSQL FormatterOne clause per line, subqueries nestedJSONL ViewerInspect newline-delimited JSON recordsJSON FormatterFormat and validate, with errors that name the causeLuhn Algorithm CheckerCheck digits without sending them anywhereIBAN ValidatorCheck a bank number's country, length and checksumJWT DecoderRead a token's claims and expiry, never transmittedMAC Address LookupVendor from the first three bytes, offlineNumber Base ConverterAny base from 2 to 36, exact at any sizeJSON to JSON SchemaInfer a draft 2020-12 schema from a sampleMeta Tag GeneratorTitle, description and social tags, ready to pasteUser Agent ParserBrowser, engine, OS and device from a UA stringFavicon GeneratorEvery size, and a real .ico fileRAID CalculatorUsable capacity for every RAID levelIP Address LookupWhich network an IP belongs to, datedList CompareCompare two lists line by lineHTML ViewerSee pasted HTML rendered with its sourceUTM BuilderCampaign links that keep their queryCSS Grid GeneratorBuild a grid, copy the CSS and the HTMLSVG ViewerSee any SVG rendered, measured and safeText to HexText to UTF-8 hex and back, byte for byteRedirect CheckerFollow a URL's redirect chain, hop by hopHTML FormatterIndent or minify, with the tags left aloneJSON to CSVObjects to a table, nesting and columns yoursHash IdentifierEvery format that fits, with the reasonASN LookupFrom an address to its AS number, and backHTML Table GeneratorFill a grid, copy escaped table markupMotorcycle VIN DecoderDecode a motorcycle VIN from the NHTSA recordHTML ValidatorLint HTML against a rule list you can readCSS Gradient GeneratorBuild a gradient, copy the exact CSSRegex TesterTest a pattern and see every match and groupCertificate DecoderRead a PEM certificate: names, dates, SANJSON String Escape and UnescapeOne literal in or out, quotes your choiceHTML Entity ConverterDecode HTML entities, or write themMarkdown Table GeneratorBuild a GFM pipe table, pipes escapedHTML to MarkdownPaste HTML, get GFM, with the drops listedCron Expression GeneratorFive fields, the sentence, the next ten runsRobots.txt TesterWhich rule wins for one URL, and whySQLite ViewerOpen a .db file: tables, rows and SELECTJSON Schema ValidatorDraft 2020-12, with the path of every failureJavaScript BeautifierRe-indent without rewriting a tokenHTML to TextStrip the tags, keep the wordsSchema Markup GeneratorJSON-LD for four types, escaped to pasteDomain ExtractorPull registrable domains out of pasted textXML to CSVPick the rows, pick the columns, get a CSVYAML ValidatorValidate YAML with the line and column namedText to HTMLEscape text into p, br or li markupJavaScript MinifierShrink JavaScript, checked token by tokenCSS Unit Converterpx, rem and em against the sizes you setParquet ViewerOpen a .parquet file: schema, rows, exportJavaScript ValidatorDoes it parse, and where does it stopLaTeX Table GeneratorEscaped tabular source from a grid or TSVRegex GeneratorBuild a pattern from examples and test itYAML to JSONConvert both ways, and yes stays a stringChmod CalculatorConvert Unix permissions between toggles, octal and symbolic stringsMAC Address GeneratorGenerate unique local-unicast MAC fixtures in four formatsRandom IP GeneratorGenerate reproducible IPv4 and IPv6 fixtures within declared rangesBulk URL OpenerReview, deduplicate and open links in explicit batchesPython PlaygroundRun Python 3.14 in your browser, with stdinJavaScript PlaygroundRun plain JavaScript in your browser, with stdinSQLite PlaygroundRun SQLite in your browser: joins, transactionsCSR DecoderRead a CSR: subject, key, SANs, signatureZIP Extractor and CreatorUnzip, zip and merge, unsafe paths caughtHex EditorEdit any file's bytes in hex, with undoKML, GPX and GeoJSON ViewerDraw and convert KML, GPX and GeoJSONXML Schema GeneratorDraft an XSD 1.0 schema from one XML sampleBcrypt GeneratorHash and verify bcrypt, 72-byte cut flaggedBatch File RenamerPreview new names, then zip the renamed copiesCurl to Code ConverterTurn curl into Fetch, Axios or Python, never runCSV to vCard ConverterContacts CSV to vCard, leading zeros keptPython FormatterRuff's own formatter, with a unified diffCSP InspectorSee which CSP directives actually applyHAR File AnalyzerInspect network logs and redact exportsSSL CheckerInspect a hostname’s TLS certificateEmail Header AnalyzerTrace declared hops and signed delaysBoolean SAT SolverSolve CNF with verified Boolean witnessesMermaid EditorRender Mermaid code to a sanitized SVG or PNGCSS Minifier and FormatterMinify or format CSS, checked against the inputJSON to Dart and TypeScriptDart classes and TypeScript types from JSONSAML DecoderRead a SAML request or response, layer by layerNBT EditorEdit binary NBT with exact 64-bit longsHTML to JSXPaste HTML, get JSX with every change listed