Uppercase to lowercase without losing your acronyms

Select the text and press Shift+F3 in Microsoft Word, which cycles the selection through small letters, capitals and a capital on every word each time you press it. Google Docs hides the same thing under Format, then Text, then Capitalization, where lowercase is one of three options. Both are quicker than this page for a sentence or two; neither will protect an acronym, which is what brings people here with a document full of them.

Only the ones you have not protected — twenty common ones are already on the list when the page loads. A press release with NASA, NHS and VAT in it comes back with all three intact, while every other capital falls. The list is yours to edit: tap a word to drop it, type any word to add it, and turn the whole thing off with the checkbox if you genuinely want everything down, including the acronyms.

Type it into the box beside the protected words, spelled exactly as you want it to come out. Matching ignores capitals but the output does not: list it as McKinsey and every MCKINSEY, mckinsey and McKINSEY in the text comes back as McKinsey, which turns the keep-list into a quiet way of normalising a supplier name that has been typed six different ways. The same trick fixes iPhone, eBay and PhD, none of which survive a plain lowercase pass.

It becomes i, because this page does exactly one thing and does not guess at grammar. That is the right answer for a search term or a file name and the wrong one for prose, so if you are rescuing a paragraph rather than a fragment, run it through the sentence case tool instead: that page rebuilds the capital on I, on each sentence opening and on the names it can identify. You can also simply add I to the keep-list here, which works but leaves the sentence openings flat.

Because Greek uses a different lowercase sigma at the end of a word, and the converter knows it. ΟΔΟΣ becomes οδος rather than οδοσ: the capital Σ maps to ς in final position and σ everywhere else, a rule built into the character standard itself rather than into this page. It is the one corner where the alphabet does not simply mirror itself, and a surprising number of tools get it wrong.

Yes — É becomes é, Ø becomes ø, Ł becomes ł, Ç becomes ç and Ş becomes ş, with the accent kept exactly where it was. Cyrillic and Armenian behave the same way. What does not change is anything in a script with no capital letters: Arabic, Hebrew, Chinese, Japanese, Korean, Thai and Hindi have no small letters to fall to, so those characters pass through the converter untouched.

Sometimes decisively, which is worth knowing before you lowercase something that has to work. Passwords are case-sensitive everywhere and must not be run through this page. The part of a web address after the domain usually is too, so /About and /about can be two different pages, while the domain itself never is. Email addresses are treated as case-insensitive by every mail provider you are likely to meet, so lowercasing a list of addresses is safe and is the usual first step before removing the duplicates.