Developer tools

Browse developer tools that run locally in your browser.

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JSON FormatterFormat, validate, and compact JSON directly in your browser.
URL Encoder and DecoderEncode and decode URLs safely using browser APIs.
Base64 Encoder and DecoderConvert text and files to or from Base64 locally.
UUID and Random String GeneratorGenerate UUIDs and random strings for development workflows.
Password and Token GeneratorGenerate strong passwords, passphrases, and random tokens locally with Web Crypto. Nothing is sent to a server.
Hash and Checksum GeneratorCalculate SHA checksums for text or local files in your browser and compare expected hashes without uploading data.
HTML Entity Encoder and DecoderEscape and unescape HTML entities locally for snippets, templates, and CMS content.
QR Code GeneratorCreate QR codes for URLs, text, Wi-Fi, and contact details in your browser.
Color Converter and Palette GeneratorConvert CSS colors, check contrast, and generate palettes in your browser.
CSV JSON Converter and Table CleanerConvert CSV, TSV, and JSON locally with table preview and safe export.
Unix Timestamp Converter and Time Zone PlannerConvert Unix timestamps, dates, and time zones locally in your browser.
JWT Decoder and Claims InspectorDecode JWT header and payload locally with claim timeline and diagnostics.
Text Diff Checker and Patch ViewerCompare text locally with side-by-side diff, summary, and patch output.
Markdown Preview Editor and HTML ExporterWrite Markdown locally with live preview, sanitized HTML, copy, and downloads.
Code Formatter and JavaScript MinifierFormat code locally and minify JavaScript without uploading or running it.
ASCII and Unicode Character TableLook up ASCII codes, Unicode code points, and copyable symbols locally.
JavaScript Regex Tester and Replace PreviewTest JavaScript regex matches, capture groups, and replacements locally.
URL Parser and Query InspectorParse URLs into protocol, host, path, query parameters, and hash, then rebuild query strings locally.
Mermaid Viewer and EditorPreview Mermaid diagrams locally, inspect syntax errors, switch themes, and export Mermaid diagrams as SVG or PNG in your browser.
Cron Expression ParserParse five-field Unix cron expressions, explain schedules, and preview upcoming runs with timezone-aware display.
Cron Expression GeneratorBuild standard five-field Unix cron expressions with presets, validation, explanations, and timezone-aware next-run previews.
YAML JSON TOML XML ConverterConvert JSON, YAML, TOML, and XML locally with formatting controls and warnings for lossy XML mapping.
JSONPath TesterEvaluate JSONPath queries against local JSON and inspect matched values, paths, and capped result arrays.
JSON to TypeScriptGenerate TypeScript interfaces or type aliases from sample JSON locally with warnings for nullable fields, arrays, and mixed shapes.
Meta Tag Previewer and GeneratorBuild title, description, Open Graph, and Twitter card tags locally with live SERP and social previews.