Lowercase to Uppercase Converter

Every letter that has a capital form is replaced by it, across the whole box at once. Digits, punctuation, spaces, line breaks and emoji stay as they are. A product label typed quickly as sku: ab-12x / size m comes out as SKU: AB-12X / SIZE M.

It works on any script with letter case, so accented Latin letters (café crème to CAFÉ CRÈME), Greek and Cyrillic all convert. Scripts without capitals, like Devanagari or Chinese, are left unchanged.

A few lowercase characters have no single capital, so Unicode's rules replace them with two letters. The output can then be longer than what you typed:

This matters if the result goes into a field with a fixed length, such as a label printer template or a database column. Compare the “characters out” figure with your limit before pasting.

Turkish needs its own check. The conversion isn't language-aware, so both the dotted i and the dotless ı become a plain I: istanbul becomes ISTANBUL, not the Turkish İSTANBUL. Fix those letters by hand.

Some strings only work in their original case, and converting them silently breaks them:

• Passwords, API keys and access codes. These are almost always case-sensitive.
• Web addresses after the domain. example.com/Page and example.com/PAGE can be different pages, or one can be missing.
• Base64 strings, hashes and file names on systems that tell cases apart.
• Code. Variable names and keywords in most programming languages are case-sensitive.

If a block mixes ordinary words with one of these, convert the words separately and paste the code or link back in as it was.

Capitals suit short text that has to stand out or match a convention: headings on a sign, column headers, form labels, postcodes and reference numbers, or a single warning word such as CAUTION. For anything longer than a line, capitals remove the shape that ascenders and descenders give to words, so save them for the parts that need emphasis and keep the rest in normal case.