Developer Tools
Developer Tools
Format, encode, decode and generate — the everyday dev toolbox.
JSON Formatter & Validator
Format, validate, beautify and minify JSON with a real editor and tree view. Instant error line/column. Try it free.
DeveloperBase64 Encode / Decode
Encode text or any file to Base64, or decode it back — with UTF-8 and URL-safe options. Try it now, all in your browser.
DeveloperURL Encoder / Decoder
Encode and decode URLs and query strings, in component, full-URL or form (x-www-form-urlencoded) mode. Also parses a URL into its components. Private, instant.
DeveloperJWT Decoder
Decode a JWT to inspect its header and payload claims, with relative expiry time and warnings for alg:none, missing exp and other risky claims. Client-side only.
DeveloperUUID Generator
Generate cryptographically strong v4 (random) or v7 (time-ordered) UUIDs online, one or many at a time. Copy or download instantly. Runs in your browser.
DeveloperHash Generator (SHA)
Generate SHA-256, SHA-1, SHA-384 and SHA-512 hashes of text or a local file, and verify a file against an expected checksum. Nothing leaves your device.
DeveloperJSON Validator
Validate JSON online for free. Check your JSON for syntax errors with the exact character position of any problem, entirely in your browser.
DeveloperJSON Minifier
Minify JSON online for free. Strip all whitespace from JSON to produce a compact, single-line payload, generated locally in your browser.
DeveloperXML Formatter
Format XML online for free. Pretty-print minified or messy XML markup into clean, indented output locally in your browser.
DeveloperHTML Formatter
Format HTML online for free. Pretty-print minified or messy HTML markup into clean, indented output locally in your browser.
DeveloperCSS Formatter
Format CSS online for free. Pretty-print a minified stylesheet into clean, indented CSS with one rule per line, in your browser.
DeveloperJavaScript Formatter
Format JavaScript online for free. Pretty-print minified or messy JavaScript source into clean, readable code in your browser.
DeveloperSQL Formatter
Format SQL online for free. Pretty-print a dense SQL query into clean, readable SQL — see this page for current browser support.
DeveloperYAML Formatter
Format YAML online. Pretty-print a YAML document — see this page for what's reliably possible in a browser today.
DeveloperXML Validator
Validate XML online for free. Check your XML markup for parser errors and confirm it's well-formed, entirely in your browser.
DeveloperJSON to XML
Convert JSON to XML online for free. Turn a JSON object into XML markup locally in your browser, no upload or sign-up needed.
DeveloperXML to JSON
Convert XML to JSON online for free. Turn simple XML markup into a JSON object locally in your browser, no upload or sign-up needed.
DeveloperJSON to CSV
Convert JSON to CSV online for free. Turn an array of JSON objects into a downloadable CSV spreadsheet, generated in your browser.
DeveloperCSV to JSON
Convert CSV to JSON online for free. Turn spreadsheet rows into a JSON array locally in your browser, no upload or sign-up needed.
DeveloperYAML to JSON
Convert YAML to JSON online for free. Turn a simple YAML mapping into JSON locally in your browser, no upload or sign-up needed.
DeveloperJSON to YAML
Convert JSON to YAML online for free. Turn a JSON object into readable YAML locally in your browser, no upload or sign-up needed.
DeveloperUUID Validator
Validate a UUID online for free. Check that a string matches the standard UUID/GUID format, entirely in your browser.
DeveloperCron Expression Generator
Build a basic cron expression online for free, for scheduling recurring jobs, generated locally in your browser.
DeveloperTimestamp Generator
Generate the current Unix timestamp online for free, in seconds since the epoch, calculated locally in your browser.
DeveloperURL Decoder
Decode a URL online for free. Turn percent-encoded characters in a URL or query string back into readable text, in your browser.
DeveloperBase64 Decoder
Decode Base64 online for free. Turn a Base64-encoded string back into readable, UTF-8 safe text locally in your browser.
About developer tools
Formatters, validators, encoders and generators for everyday development work — JSON, XML, YAML, Base64, URL encoding, hashes, UUIDs, JWT decoding and more. Everything runs client-side: paste your code or data, get the result, nothing is transmitted. That's deliberate — you should be able to format a config file or decode a token without wondering whether it was logged somewhere. For anything involving a real secret, local processing is the only safe option, and it's what these tools do by default.
Frequently asked questions
Is it safe to paste sensitive data into these tools?
The processing happens entirely in your browser — nothing is sent to a server. That said, avoid pasting production secrets on a shared or public computer, since the risk there is the machine itself, not the tool.
Do these tools work offline?
Once a tool page has loaded, most of the developer tools continue to work without a connection, since the logic is all client-side JavaScript.
Why does the JSON formatter reject my file when it looks valid?
JSON is strict: trailing commas, single quotes, unquoted keys and comments are all invalid even though other languages allow them. The formatter points to the exact line and column of the first error.