Developer Tools

Utilities for everyday development work: formatting, decoding, encoding, inspecting and network addressing. Nothing you paste is ever sent to a server — the one exception is the public IP lookup, which by its nature has to ask something outside your browser, and says so on the page.

• JSON Formatter

  Paste JSON to pretty-print it with consistent indentation, or minify it back down. Invalid JSON is reported with the exact line and column so you can find the problem.

• JSON Minifier

  Strip every unnecessary character from JSON to make it as small as possible for transmission or storage. The result is byte-for-byte equivalent data.

• JSON Validator

  Check whether your JSON is valid. If it is not, you get the exact line and column of the first error rather than a vague parser message.

• Base64 Encoder

  Encode any text to Base64, including emoji and non-Latin scripts. Switch to the URL-safe alphabet when the result has to travel in a URL.

• Base64 Decoder

  Decode Base64 back to readable text. Standard and URL-safe alphabets both work, padded or not, and line breaks in pasted input are ignored.

• URL Encoder

  Percent-encode text so it can travel safely in a URL. Encode a single query value, or fix only the illegal characters in a complete address.

• URL Decoder

  Decode a percent-encoded URL back to readable text. If the result is a full URL, its query parameters are broken out so you can see what it carries.

• JWT Decoder

  Paste a JSON Web Token to read its header and payload. Timestamp claims are expanded into readable dates, and the token never leaves your browser.

• UUID Generator

  Generate UUIDs in bulk. Version 4 is fully random; version 7 begins with a timestamp so the values sort chronologically. Both use your browser's secure random source.

• UUID Validator

  Check whether a UUID is well-formed and identify its version. For v1 and v7 the embedded creation timestamp is extracted and shown.

• Password Generator

  Generate a strong random password using your browser's cryptographic random source. Nothing is transmitted, logged or stored — the password exists only on your device.

• Unix Timestamp Converter

  Convert a Unix timestamp to a readable date in every common format, or go the other way. Seconds and milliseconds are detected automatically.

• Timestamp Generator

  The current moment in every format you are likely to need: Unix seconds and milliseconds, ISO 8601, UTC, SQL datetime and RFC 2822.

• Regex Tester

  Test a regular expression against sample text and see matches highlighted as you type, with capture groups broken out for every match.

• Lorem Ipsum Generator

  Generate placeholder text by paragraph, sentence or exact word count. The output is deterministic, so the same settings give the same text every time.

• Word Unscrambler

  Enter your tiles and see every word they can make, best score first — including the shorter words that fit when the seven-letter play will not.

• Hash Generator

  Generate MD5, SHA-1, SHA-256, SHA-384 and SHA-512 digests of any text simultaneously. Everything is computed in your browser.

• HTML Formatter

  Re-indent HTML so its nesting is readable. Fragments work as well as whole documents, and the contents of pre, script and style blocks are left exactly as written.

• CSS Formatter

  Re-indent CSS so it is readable, or minify it for production. Nested at-rules, comments and quoted values are all handled correctly.

• XML Formatter

  Re-indent XML so its structure is readable, and find out immediately if it is not well-formed. CDATA sections and declarations are preserved exactly.

• YAML to JSON

  Convert YAML into JSON. Parse errors are reported with a line and column so you can find the problem, which in YAML is usually indentation.

• JSON to YAML

  Convert JSON into YAML. Strings are quoted only where quoting is necessary to stop them being read back as a number, boolean or null.

• What Is My IP

  Your public IP address as the rest of the internet sees it, plus the details your browser reveals to every site you visit.

• Subnet Calculator

  Enter an address and a prefix to get the network, broadcast, mask, wildcard, host range and host count — and split the block into equal subnets.

• CIDR to Subnet Mask

  Convert a prefix length such as /24 into its subnet mask and back again, with the full reference table for every prefix from /0 to /32.

• IP Address Converter

  Convert an IPv4 address between dotted decimal, its 32-bit integer value, binary and hexadecimal. Paste any notation and the rest are derived.

• Chmod Calculator

  Tick the permissions you want and get the command to run. Converts between octal modes such as 755 and symbolic ones such as rwxr-xr-x, in both directions.