Free online tools that just work

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.

Convert between metric and imperial units instantly. Each converter uses the exact internationally defined factor, so results match official conversion tables.

• KG to LBS

  Convert kilograms to pounds quickly and accurately. Type a value in kilograms and the equivalent in pounds appears instantly.

• LBS to KG

  Convert pounds to kilograms quickly and accurately. Type a value in pounds and the equivalent in kilograms appears instantly.

• Grams to Ounces

  Convert grams to ounces quickly and accurately. Type a weight in grams and the equivalent in ounces appears instantly.

• Ounces to Grams

  Convert ounces to grams quickly and accurately. Type a weight in ounces and the equivalent in grams appears instantly.

• KM to Miles

  Convert kilometres to miles quickly and accurately. Type a distance in kilometres and the equivalent in miles appears instantly.

• Miles to KM

  Convert miles to kilometres quickly and accurately. Type a distance in miles and the equivalent in kilometres appears instantly.

• Meters to Feet

  Convert metres to feet quickly and accurately. Type a length in metres and the equivalent in feet appears instantly.

• Feet to Meters

  Convert feet to metres quickly and accurately. Type a length in feet and the equivalent in metres appears instantly.

• CM to Inches

  Convert centimetres to inches quickly and accurately. Type a length in centimetres and the equivalent in inches appears instantly.

• Inches to CM

  Convert inches to centimetres quickly and accurately. Type a length in inches and the equivalent in centimetres appears instantly.

• Meters to Inches

  Convert metres to inches quickly and accurately. Type a length in metres and the equivalent in inches appears instantly.

• Inches to Meters

  Convert inches to metres quickly and accurately. Type a length in inches and the equivalent in metres appears instantly.

• Celsius to Fahrenheit

  Convert Celsius to Fahrenheit quickly and accurately. Type a temperature in °C and the Fahrenheit equivalent appears instantly.

• Fahrenheit to Celsius

  Convert Fahrenheit to Celsius quickly and accurately. Type a temperature in °F and the Celsius equivalent appears instantly.

• Liters to Gallons

  Convert litres to US gallons quickly and accurately. Type a volume in litres and the equivalent in gallons appears instantly.

• Gallons to Liters

  Convert US gallons to litres quickly and accurately. Type a volume in gallons and the equivalent in litres appears instantly.

• Square Meters to Square Feet

  Convert square metres to square feet quickly and accurately. Type an area in m² and the equivalent in ft² appears instantly.

• Square Feet to Square Meters

  Convert square feet to square metres quickly and accurately. Type an area in ft² and the equivalent in m² appears instantly.

Everyday maths without the spreadsheet. Every calculator shows the formula it used, so you can check the working rather than trusting a black box.

• Percentage Calculator

  Answer the three questions people actually ask about percentages: what is X% of Y, X is what percent of Y, and how much did a value change. Each answer shows its working.

• Percentage Increase Calculator

  Find the percentage increase between two values, or apply an increase to a starting figure. The working is shown so you can check the result.

• Percentage Decrease Calculator

  Find the percentage decrease between two values, or reduce a starting figure by a percentage. The working is shown so you can check the result.

• VAT Calculator

  Add VAT to a net price, or work backwards from a gross price to find the tax it contains. Both directions show the net, VAT and gross amounts.

• Discount Calculator

  Find the final price after a discount and how much you save. The stacked mode handles "extra 10% off sale prices", where the second cut applies to the reduced figure.

• Age Calculator

  Work out an exact age in years, months and days from a date of birth — plus the totals in weeks and days, and how long until the next birthday.

• Date Difference Calculator

  Count the time between two dates in days, weeks and months, with a separate weekday-only total for working out business days.

• Compound Interest Calculator

  See how an investment grows over time with compound interest. Add a monthly contribution and choose how often interest compounds to model a real savings plan.

• Loan Payment Calculator

  Work out the monthly payment on a loan or mortgage, and see how much of the total goes on interest over the life of the loan.

• Salary Calculator

  Convert pay between hourly, daily, weekly, monthly and yearly figures. Set your own hours per week and working weeks per year for an accurate comparison.