Developer Tools
Formatters, validators and utilities for developers and data work.
JSON FormatterFormat, beautify, minify and validate JSON instantly — right in your browser.JSON ValidatorValidate JSON instantly and find syntax errors with the exact line, column and position — right in your browser.Base64 Encoder/DecoderEncode text to Base64 and decode Base64 back to text with full Unicode and emoji support — 100% in your browser.URL Encoder / DecoderEncode text for URLs with encodeURIComponent or encodeURI, and decode percent-encoded strings.Unix Timestamp ConverterConvert Unix timestamps to readable dates and back, with seconds and milliseconds support.Hash GeneratorCompute MD5, SHA-1, SHA-256 and SHA-512 hashes of any text, entirely in your browser.JWT DecoderDecode JSON Web Tokens to inspect the header, payload and expiration — without sending the token anywhere.Diff CheckerCompare two blocks of text line by line and see exactly what was added, removed or left unchanged.Regex TesterTest a regular expression against your own text, highlight every match and inspect capture groups.JSON to CSV ConverterTurn a JSON array of objects into clean CSV, ready for Excel, Google Sheets or a database import.Number Base ConverterConvert between binary, octal, decimal and hexadecimal with exact BigInt precision.HTML Entity EncoderEscape or decode HTML entities, with a minimal mode for code and a full mode for every special character.CSS Box Shadow GeneratorDesign a CSS box-shadow with live sliders, presets and a preview, then copy the ready-to-paste rule.Border Radius GeneratorShape four corners independently, link them together and copy the CSS border-radius rule.JSON to TypeScriptTurn any JSON payload into clean TypeScript interfaces or type aliases, generated in your browser.Cron Expression ParserExplain a cron expression in plain language and preview the next run times, right in your browser.Markdown to HTMLConvert Markdown into clean HTML, preview it in a sandbox and copy or download the result.HTML to MarkdownConvert HTML into tidy Markdown — headings, lists, tables, links and code blocks included.QR Code ScannerDecode a QR code from an image and read the link, Wi-Fi details or contact card it contains.JSON to Go StructGenerate Go structs with JSON tags from a JSON sample.JSON to Python ModelGenerate Python dataclasses or Pydantic models from a JSON sample.CIDR CalculatorExpand a CIDR block into its network, mask, wildcard and host range.JSON to YAMLConvert JSON into clean, readable YAML with configurable indent and key sorting.YAML to JSONConvert YAML into JSON, including multi-document files and key sorting.cURL to CodeTurn a curl command into JavaScript, Python, Go or PHP code.LLM Token CounterCount tokens for GPT, Claude and Gemini models, check the context window left, and see how one Chinese character can cost 0.6 or 1.2 tokens depending on the model.Browser Info & Screen Resolution DetectorRead your screen resolution, viewport size, device pixel ratio, GPU, CPU cores, time zone and connection quality from one table — including the physical pixel count behind the scaling.What Is My IP?Show the public IP address your device presents to the internet, plus country, the Cloudflare data centre serving you, TLS version, protocol and VPN indicators.