Free Online JSON & Developer Tools

Format, convert, decode, and encode — right in your browser.

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Working with data means constantly translating between formats: JSON from an API needs to become a spreadsheet, a token needs inspecting, a URL needs encoding before it survives a query string. These four developer tools handle those translations without ceremony. The JSON Formatter validates pasted JSON and pinpoints syntax errors, then beautifies or minifies it. The JSON to CSV Converter flattens arrays of objects — including nested ones — into spreadsheet-ready CSV for Excel or Google Sheets. The JWT Decoder reads a token’s header and payload so you can check algorithms, issuers, and expiry times. The URL Encoder & Decoder percent-encodes text for links or decodes mangled URLs back to readable form. Everything runs entirely in your browser: paste, convert, copy, done. No accounts, no uploads, no waiting on a server — your data never leaves the page.

Tools in this collection

{ }JSON FormatterValidate JSON and pinpoint syntax errors, or beautify it with clean indentation. Minify payloads to a single line when size matters. CSVJSON to CSVTurn JSON arrays into spreadsheet-ready CSV for Excel or Google Sheets. Nested objects flatten into clean columns automatically. JWTJWT DecoderRead a token’s header and payload — algorithm, issuer, expiry, claims — without the token ever leaving your browser. URLURL Encoder & DecoderPercent-encode text for query strings and links, or decode mangled URLs back to readable form.

Other collections

AaText & Writing ToolsBrowse the text & writing tools collection. %CalculatorsBrowse the calculators collection. ↔Converters & GeneratorsBrowse the converters & generators collection.