Random Case Converter, Free and Private
Give every letter a random upper or lower case in your browser, or alternate the case from a random start. Draw again until it looks right, then copy it. Nothing is uploaded.
0 characters, 0 bytes
0 characters, 0 bytes
About the random case converter
This page gives every letter in your text a random case, upper or lower, in your browser. Type or paste a sentence and the output shows it with a mix of capitals and small letters, such as hELlo WoRLd. Press Randomise again for a new mix, and repeat until the result looks the way you want. Turn on Strictly alternate when you want the familiar up-and-down pattern instead, where the case changes on every letter and only the case of the first letter is left to chance. Nothing is uploaded: the letters are shuffled on your device and the text never leaves it.
How to randomise the case of text
Steps
- Type or paste your text into the Input box. Random case is already selected under Case when you open this page.
- Read the result in Output. Every letter has been given an upper or lower case of its own.
- Press Randomise again to draw a new pattern for the same text. The letters stay the same; only their case changes.
- Switch on Strictly alternate for an alternating pattern that starts with a random case.
- Press Copy to copy the result, or Clear to start again.
Privacy
The conversion runs entirely in your browser. Your text is never sent to our servers, and it is forgotten when you close or reload the tab.
How the randomness works
Each letter needs a single yes-or-no decision: upper case or lower case. The tool asks the browser's cryptographic random number generator, the Web Crypto getRandomValues function, for random bits and uses one bit per letter. Every letter therefore has an even, independent chance of each case, and earlier letters do not influence later ones. Because the choices are independent, runs of three or four capitals in a row happen now and then, exactly as runs of heads happen when you toss a coin.
The random source is only used to pick case. Characters that are not letters, such as digits, punctuation, spaces, emoji and line breaks, are copied to the output unchanged, and they do not use up a random bit. Letters in any script that has case are handled, so straße, ÉCOLE and Greek or Cyrillic words are randomised too. Scripts without case, such as Chinese or Japanese, pass through as they are.
Random case and alternating case
Fully random
Each letter is decided on its own. The result looks irregular, which is what most people mean by random capitalisation. The same text gives a different result each time you press Randomise again.
Strictly alternate
The case flips on every letter, counting letters only, so a space or a comma does not break the pattern. Only the first letter is random, which means there are exactly two possible results: one starting with a capital and one starting with a small letter. The main text case converter also has a fixed aLtErNaTiNg case that always starts in lower case.
Things to know
- The output changes as you type. Each edit draws a fresh pattern for the whole text, so finish typing first and then press Randomise again until you are happy.
- It is not a password generator. The randomness only decides upper or lower case of letters you supplied, so the result is as guessable as the original words.
- Case rules follow your browser. Letters are converted with your browser's locale rules. A browser set to Turkish turns
iinto a dotted capitalİ. - Some letters change length. In upper case
ßbecomesSS, so the output can be a character longer than the input.
When people use random case
Random capitalisation is mostly playful. It is the style of the mocking meme text that repeats someone's words back in an exaggerated voice, and it turns up in chat messages, captions and stickers. Designers use it for a hand-made or ransom-note look in posters, and testers use it to check that search boxes, user name checks and database lookups ignore case as they should. If you need a predictable result instead, choose a fixed case such as UPPER CASE or Title Case on the text case converter.
Open-source credits
The random case logic is implemented in-house. It draws its random bits from the Web Crypto API (crypto.getRandomValues) and uses the case mappings built into JavaScript (toLocaleUpperCase and toLocaleLowerCase), which follow the Unicode Standard's case mapping data. No third-party library is involved.
Related tools
Flip the order of the letters with Reverse Text, tidy spacing with the Whitespace Remover, or encode the result for a web address with the URL encoder.
Frequently asked questions
Why do I sometimes get several capitals in a row?
Each letter gets its own independent coin toss, so runs of three or four capitals or small letters happen by chance, just as a coin can land heads several times running. Press Randomise again for a new draw, or switch on Strictly alternate for a pattern that changes on every letter.
What is the difference between random case and alternating case?
Random case decides upper or lower for every letter separately, so the pattern is irregular. With Strictly alternate on, the case flips on every letter and only the first letter is random, which leaves just two possible results for any text, one starting with a capital and one without.
Do digits, punctuation and emoji change in random case?
No. Only letters from scripts that have upper and lower case are changed. Digits, punctuation, spaces, emoji, line breaks and letters from caseless scripts such as Chinese are copied to the output exactly as you typed them, and they do not shift the alternating pattern either.
Where does the randomness in the random case converter come from?
It comes from your browser's cryptographic random number generator, the Web Crypto getRandomValues function, which supplies one random bit for every letter. The bits are produced on your device, so your text and the pattern applied to it are never sent anywhere.
Can I use random case text as a password?
It is a poor choice. Randomising case only adds one guessable choice per letter to words you picked yourself, and attackers routinely try case variations of common words. Use a dedicated password generator that creates long random strings from a large character set instead.