100% private — zero uploads, ever
Developer tools that work
in your browser
Every tool runs entirely client-side. Your JSON, JWTs, keys, and code never touch a server. Fast, free, and works offline after first visit.
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JSON
JSON FormatterFormat, beautify, and minify JSON instantly in your browser. Syntax highlighting, error detection, sort keys, and one-click Fix. Your data never leaves your device.JSON ValidatorValidate JSON with precise error location and human-friendly explanations. Supports JSON5 and JSONC with comments and trailing commas. 100% client-side.JSON ViewerExplore JSON as a collapsible tree with virtualized rendering for 100k+ nodes. Search keys and values, copy JSONPath, and navigate large structures instantly.JSON DiffCompare two JSON objects semantically — key-order insensitive. Side-by-side color-coded diff with added, removed, and changed values highlighted clearly.
Converters
JSON to CSVConvert JSON arrays to CSV instantly. Handles nested objects with dot-notation flattening, custom delimiters, and large files via Web Worker. No data uploaded.CSV to JSONConvert CSV files to JSON arrays instantly in your browser. Auto-detects headers and delimiters, handles quotes and escaping correctly. Your data stays private.JSON to YAMLConvert JSON to YAML format instantly in your browser. Clean, readable output with proper indentation. No upload, no account — 100% private.YAML to JSONConvert YAML to JSON instantly in your browser. Handles multi-document YAML, anchors, and aliases. Your configuration data stays completely private.JSON to XMLConvert JSON to XML in your browser. Choose root element name, handle arrays with configurable element names. Zero uploads, zero tracking.XML to JSONConvert XML to JSON instantly in your browser. Handles attributes, namespaces, and CDATA sections. Fast, private, and works offline.
Encoders
JWT DecoderDecode JWT headers and payloads instantly. Human-readable claim table, expiry countdown, and optional signature verification via WebCrypto. Token never uploaded.Base64 EncodeEncode text or files to Base64 in your browser. URL-safe variant, data URI generator, image preview for encoded images. Nothing is uploaded or stored.Base64 DecodeDecode Base64 strings to text or files in your browser. Auto-detects image data and shows a preview. URL-safe variant supported. Completely private.Hash GeneratorGenerate MD5, SHA-1, SHA-256, SHA-384, SHA-512, and HMAC hashes for text or files (including files over 1GB). Streaming, private, and 100% browser-based.
Text
Regex TesterTest regular expressions live with match highlighting, capture group tables, and replace preview. Includes a cheatsheet of common patterns. 100% in-browser.Diff CheckerCompare two texts side-by-side or inline. Word, character, and line diff modes, ignore-whitespace and ignore-case toggles. Your content never leaves your browser.
Web
SVG OptimizerOptimize SVG files with SVGO in your browser. Per-plugin checkboxes, before/after size comparison, live visual preview, export as SVG or PNG. No upload.Timestamp ConverterConvert Unix timestamps to human-readable dates and back. Live current timestamp, auto-detect seconds/milliseconds, timezone selector, ISO 8601 output.Cron ParserParse cron expressions into plain English, see the next 10 run times, and build expressions with an interactive field-by-field UI. Works offline.Color ConverterConvert colors between HEX, RGB, HSL, OKLCH, and LAB. Live swatch preview, EyeDropper API, and WCAG contrast checker. All in your browser, no upload.
No tools match your search.
Zero uploads
Processing happens in your browser using JavaScript. Data never touches our servers — we don't have any.
Instant results
No round trips, no spinners. Heavy operations use Web Workers so the UI stays snappy even on large files.
Works offline
Installable as a PWA. After first visit, every tool works without an internet connection.