Online tools · UK
4devskit
Generate and validate UK documents in seconds. Fast, free, and 100% in your browser — ideal for development and testing.
62 generators10 validators
About us
4devskit is a free online toolkit to generate and validate test data in the browser.
4devskit (4devs kit) gathers country-specific generators and validators plus text, math, date, and encoding utilities.
Generators
- NINO GeneratorGenerate UK National Insurance Numbers with valid format.
- BTW-nummer-generatorGenereer Belgische BTW-nummers.
- Postcode GeneratorGenerate UK-format postcodes for forms and mocks.
- Sort Code GeneratorGenerate 6-digit UK bank sort codes.
- Phone GeneratorPhone Generator.
- IBAN-generatorGenerera svenska IBAN-nummer.
- Driver's License GeneratorDriver's License Generator.
- NHS Number GeneratorNHS Number Generator.
- Person GeneratorPerson Generator.
- Credit Card GeneratorGenerate fictional cards that pass the Luhn check.
- Password GeneratorGenerate strong passwords with composition options.
- Random Number GeneratorDraw random numbers with range and quantity controls.
- Lorem Ipsum GeneratorGenerate placeholder text for layouts and mockups.
- Fancy Text GeneratorConvert text into Unicode fancy styles for bios, titles, and mock content.
- Symbols to CopyCopy arrows, currency signs, and special characters for UI and content work.
Validators
- NINO ValidatorValidate National Insurance Number format and prefix rules.
- BTW-nummer-validatorValideer Belgische BTW-nummers.
- Postcode ValidatorValidate common UK postcode patterns.
- Sort Code ValidatorValidate 6-digit UK sort codes.
- Phone ValidatorPhone Validator.
- IBAN-validatorValidera svenska IBAN-nummer.
- Driver's License ValidatorDriver's License Validator.
- NHS Number ValidatorNHS Number Validator.
- Credit Card ValidatorValidate card numbers with the Luhn algorithm and detect the card brand.
- Password Strength CheckerRate password strength as weak, medium, or strong for signup and QA flows.
String functions
- Spell CheckerCheck spelling with the browser’s built-in dictionary.
- Sort AlphabeticallySort lines of text alphabetically.
- Character CounterCount characters, words, and lines.
- Word Occurrence CounterCount how often a word appears.
- Text to HTMLEscape text to HTML in the browser.
- Truncate TextLimit text length with an ellipsis.
- Split StringSplit text by a separator.
- Character InfoUnicode, decimal, hex, and UTF-8 for a character.
- Reverse TextReverse character order.
- Case ConverterConvert upper, lower, title, and sentence case.
- Number to WordsWrite integers in English words.
- Remove AccentsStrip accents and diacritics.
- Replace NewlinesRemove or replace line breaks.
Mathematics
- Roman Numeral ConverterConvert decimals and roman numerals.
- Factor NumberFactorize into primes.
- GCD CalculatorCompute the greatest common divisor.
- LCM CalculatorCompute the least common multiple.
- Percentage CalculatorCalculate percentages quickly.
- Rule of ThreeSolve simple proportions.
- Division RemainderCompute quotient and remainder.
Area calculation
- Circle AreaCalculate the area of a circle.
- Square AreaCalculate the area of a square.
- Rectangle AreaCalculate the area of a rectangle.
- Triangle AreaCalculate the area of a triangle.
- Pentagon AreaCalculate regular pentagon area.
- Hexagon AreaCalculate regular hexagon area.
- Regular Polygon AreaCalculate regular polygon area.
- Rhombus AreaCalculate rhombus area from diagonals.
- Trapezoid AreaCalculate trapezoid area.
- Parallelogram AreaCalculate parallelogram area.
- Ellipse AreaCalculate ellipse area.
- Annulus AreaCalculate circular ring area.
- Circular Sector AreaCalculate circular sector area.