Text to uppercase, including the letters that misbehave

Sometimes, and always upwards. The German ß has no single capital in the default mapping, so it opens out into two letters: straße is six characters and STRASSE is seven. The typographic ligatures that PDFs leave in copied text do the same thing — fi becomes FI and ffl becomes FFL, turning one character into two or three. That matters whenever a limit is involved, because a 60-character page title or a database field sized to the original can overflow on a conversion that looks purely cosmetic.

There are two correct answers, and this page offers both. The traditional one is SS, which is what every browser produces by default and what most German prose still uses. The other is ẞ, the capital sharp s, which became an official variant in the 2017 revision of the German spelling rules and is now used on identity documents so that a surname is not altered by being set in capitals. Switch it on with the checkbox that appears whenever your text contains a ß; it keeps the length of the line unchanged, which SS does not.

Because Turkish has two separate letter i, and the pairing is not the one English uses. The dotted i rises to a dotted İ, and the dotless ı rises to a plain I, so istanbul becomes İSTANBUL and ışık becomes IŞIK. Convert Turkish text with the default English mapping and you get ISTANBUL, which is a different word to a Turkish reader. The return journey is worse: an İ lowercased without the Turkish setting leaves the dot behind as a separate mark hovering over an ordinary i.

Because that is how Greek capitals are written — an accent is dropped when a word is set in capitals, so Ελλάδα becomes ΕΛΛΑΔΑ and not ΕΛΛΆΔΑ. The default mapping in every browser keeps the accent, which is technically a faithful letter-for-letter conversion and typographically wrong. Choosing Greek in the language selector applies the convention. The dieresis is the exception and stays put, because it separates two vowels rather than marking a stress.

Yes, and this page keeps them: ÉTÉ, À BIENTÔT, ÇA VA. The habit of dropping them is a legacy of mechanical typewriters and early typesetting, where accented capitals were awkward or missing, and the Académie française has been explicit that the accent is part of the spelling in capitals as much as in lower case. Dropping it can change the word — a UN ÉLÈVE that loses its accents reads differently — so a converter that strips accents from French is losing information, not tidying it.

Because capitals are physically wider than small letters, quite apart from any change in the character count. Every capital is drawn to the full height of the line with no narrow ascender or descender to save space, so a line in capitals typically runs ten to fifteen per cent wider than the same line in sentence case in the same font and size. Combine that with a ß or a ligature that also adds characters and a button label, a table header or a navigation item that fitted comfortably will overflow. The panel above sets your own line in both cases so you can judge it before it breaks a layout.

No — small caps is a property of the font, not a change to your letters, and the difference matters. Setting text in small caps leaves the underlying words exactly as written and asks the typeface to draw the lower-case letters as small capitals, so the text can still be searched, read aloud correctly and later un-styled. Converting to capitals rewrites the words themselves, throws away the record of which letters were capitals, and is read by some screen readers as an abbreviation to be spelled out. Use capitals when the text must genuinely be capitals; use small caps when you only want the look.