Developer tools
Formatters, encoders, validators and the small stuff you script twice.
61 of the 77 run entirely in your browser — nothing uploaded, working offline — and every page says which before you pick a file.
77 tools
- JSON FormatterFormat, validate, and minify JSON — entirely in your browser.
- YAML FormatterPretty-print YAML and convert to/from JSON.
- XML FormatterPretty-print and validate XML.
- Text DiffSide-by-side and inline diff for any two texts.
- Regex TesterTest regular expressions with live highlighting.
- JWT DecoderDecode and inspect JSON Web Tokens.
- Base64 Encode / DecodeRound-trip text or files through Base64.
- Hash GeneratorMD5, SHA-1, SHA-256, SHA-512 of any text or file.
- QR Code GeneratorTurn any URL or text into a QR code. Download PNG or print-ready SVG.
- QR Code ReaderDecode QR codes from an image.
- Barcode ScannerRead any barcode or QR code from an image — 1D and 2D.
- Markdown to PDFRender Markdown into a clean PDF.
- URL Encode / DecodePercent-encode or decode URLs and query strings.
- HTML ↔ MarkdownConvert between HTML and Markdown — both directions, in your browser.
- Summarize TextSummarize long documents with a self-hosted LLM.
- Translate TextTranslate between 30+ languages without uploading to OpenAI.
- Rewrite TextTone, grammar, and clarity rewrites — locally hosted.
- CSV to JSONParse CSV and emit JSON, with header detection and type inference.
- JSON to CSVFlatten an array of objects into CSV.
- SQL FormatterPretty-print SQL with configurable dialect.
- HTML Formatter / MinifierFormat or minify HTML.
- CSS Formatter / MinifierFormat or minify CSS.
- JavaScript / TypeScript FormatterPrettier-driven formatting for JS, TS, JSX, TSX.
- ZIP CreatorBundle multiple files into a single ZIP — entirely in your browser.
- ZIP ExtractorExtract a ZIP into individual files.
- Credit Card ValidatorLuhn check + brand detection (Visa / Mastercard / Amex / Discover / etc).
- IBAN ValidatorValidate IBAN by country format and mod-97 checksum.
- SWIFT / BIC ValidatorValidate SWIFT/BIC bank identifier codes (ISO 9362).
- US Routing Number ValidatorABA routing number checksum validator.
- VIN DecoderDecode 17-character Vehicle Identification Number — year, region, manufacturer.
- ISBN ValidatorValidate ISBN-10 and ISBN-13 with checksum.
- ISSN ValidatorValidate International Standard Serial Number checksum.
- UPC / EAN ValidatorValidate UPC-A, UPC-E, EAN-8, EAN-13 barcode checksums.
- Email Address ValidatorSyntax check + disposable detection + suggested correction.
- Phone Number ValidatorE.164 format + country detection + national format.
- SSN Format ValidatorValidate US Social Security Number format (no actual lookup).
- MAC Address ValidatorValidate + normalize MAC address (multiple formats supported).
- IP Address ValidatorValidate IPv4 / IPv6 + classify (public/private/loopback/multicast).
- Password Strength MeterEntropy-based strength + crack-time estimate + zxcvbn-style feedback.
- Luhn-Valid Test Number GeneratorGenerate Luhn-valid card numbers for testing (Visa, MC, Amex prefixes).
- Data URI BuilderEncode/decode data: URIs with proper MIME and base64 handling.
- Color Format ValidatorValidate hex / rgb / hsl / oklch and convert between them.
- URL Parser & ValidatorParse URL into protocol/host/path/query/hash + validate.
- UUID ValidatorValidate + identify UUID version (1/3/4/5/7).
- SemVer Version ValidatorParse + compare semantic versions, check ranges (^, ~, >=, <).
- Mock Data / Fake JSON GeneratorGenerate fake users, products, orders — JSON, CSV, or SQL output.
- JSON → TypeScript / Zod / Pydantic / SQLGenerate TypeScript interfaces, Zod schemas, Pydantic models, SQL CREATE, JSON Schema, Avro, Java POJO from a JSON sample.
- API Request Inspector / Mini PostmanInspect, format, and document a captured HTTP request (cURL, fetch, Postman).
- Regex Visualizer & Cheat SheetBreak a regex into tokens with explanations + match preview.
- Cubic Bezier Easing EditorVisualize cubic-bezier(x1, y1, x2, y2) easing curves.
- CSS clip-path GeneratorGenerate polygon, circle, ellipse, inset clip-path values.
- CSS Animation Keyframes BuilderBuild @keyframes from from/to declarations.
- CORS Header BuilderCompose Access-Control-* headers and validate against a request.
- Content Security Policy BuilderBuild a CSP header from drop-down policies for each directive.
- Cache-Control Header BuilderCompose Cache-Control with presets for static / API / dynamic content.
- HTTP Signature DebuggerDebug HMAC / Stripe / GitHub-style request signatures.
- TOTP / 2FA Code GeneratorGenerate live TOTP codes from a base32 secret (RFC 6238).
- otpauth:// URI & QR BuilderBuild the otpauth:// URI for Google Authenticator / 1Password / Authy.
- HTTP Request → cURL / fetch / axios / PythonBuild an HTTP request and export to cURL, fetch, axios, Python requests.
- User-Agent String BuilderBuild / parse / spoof User-Agent strings.
- WebSocket Connection TesterConnect to a WS endpoint, send/receive messages, view frames.
- GraphQL Schema → TypeScriptGenerate TypeScript interfaces from a GraphQL SDL schema.
- SQL Schema → TypeScript / ZodParse CREATE TABLE statements and emit TS types or Zod schemas.
- .env File Parser & ValidatorParse / format / sort / validate .env files; export to JSON or YAML.
- Minify / Beautify CodeMinify or pretty-print HTML / CSS / JS / JSON / SQL in one tool.
- Wei / Gwei / Ether ConverterConvert between Ethereum units: wei, gwei, ether.
- Ethereum Gas Cost CalculatorEstimate transaction cost from gas price + gas used.
- Bitcoin / Ethereum Address ValidatorValidate BTC (P2PKH/P2SH/Bech32) and ETH (EIP-55 checksum) addresses.
- BIP39 Mnemonic GeneratorGenerate a secure 12/15/18/21/24-word seed phrase. Educational only.
- Hash Function Suite (SHA / Keccak / BLAKE)Compute SHA-256/512, SHA-3, Keccak-256, BLAKE2, RIPEMD-160 simultaneously.
- HMAC PlaygroundCompute HMAC-SHA1/SHA256/SHA384/SHA512 with a secret + message.
- Ed25519 / ECDSA Sign + VerifyGenerate keypair, sign messages, verify signatures with Web Crypto.
- Crypto Wallet Address Generator (Educational)Generate a new keypair + address for BTC or ETH (testing only).
- Webpage Screenshot GeneratorCapture a full-page or above-the-fold screenshot of any URL via headless Chromium.
- YouTube Thumbnail DownloaderDownload high-res YouTube thumbnails (max-res, HD, SD, default) from a URL or ID.
- YouTube Transcript DownloaderDownload captions / transcript for any public YouTube video.
- Full Page Screenshot ToolLong scrolling screenshot of any URL — useful for SEO audits and design review.