Case Converter

How this works

Each output is a fixed pipeline of one operation, applied to whatever you paste. There is no mode selector because there is no reason for one: showing all four costs nothing and saves you a click, and it also lets you SEE the difference between Title Case and Sentence case, which is the thing people are usually actually trying to work out. UPPERCASE and lowercase are straightforward character conversions. Title Case capitalises the first letter of every word and lowercases the rest. Sentence case lowercases everything and then capitalises two things: the first letter of the text, and the first letter after any . ! or ? that is followed by a space. Be aware that Title Case here is MECHANICAL - it capitalises every word without exception. Real title styles do not: most style guides leave short words like 'a', 'of', 'the' and 'in' lowercase unless they start the title, and they disagree with each other about which words qualify. No automatic converter can apply a style guide you have not named, so treat the output as a starting point for a headline rather than a finished one. Sentence case finds sentences with a simple rule - punctuation followed by a space - and that rule has one clear failure. An abbreviation ends in a full stop and is followed by a space, so it reads as the end of a sentence: 'approx. five apples' becomes 'Approx. Five apples'. The same happens after 'e.g.', 'Dr.', 'etc.' and any other abbreviation mid-sentence. The space requirement is what keeps it safe elsewhere: a decimal like 3.50 has no space after the point, so it is left alone, and so is a run like one.two.three. Detecting sentences properly means telling an abbreviation from a full stop, which needs to know the words - so the honest trade is a rule that is right most of the time and predictable when it is wrong. Both lowercase and Sentence case also lowercase proper nouns anywhere except the start of a sentence, because neither has any way to know that 'london' is a place or that 'march' is a month rather than a verb. Nothing you paste is transmitted. The conversion runs in your own browser through a fixed list of allowed operations, so there is no upload, no server and nothing stored. That matters more than it sounds for a tool people paste half-finished documents into.

Common questions

Why is there no mode dropdown?

Because showing all four at once costs nothing and saves you from choosing before you know what you want. It also puts Title Case and Sentence case side by side, which is genuinely the most common thing people come to a tool like this to work out - they look similar in description and completely different in practice.

Is my text sent anywhere?

No. The conversion happens in your own browser using a fixed list of allowed text operations - there is no upload, no server call and nothing stored. This matters more than it might sound, because the things people paste into case converters are frequently half-finished emails, draft contracts and other people's names.

Why did Title Case capitalise 'The' and 'Of'?

Because it applies the rule mechanically to every word. Real title styles do not - most leave short words like 'a', 'an', 'the', 'of', 'in' and 'on' lowercase unless they open the title, and the major style guides disagree with each other about exactly which words those are and how long a word has to be before it counts. A converter cannot apply a style guide you have not told it about, so use this as a starting point and fix the small words by eye.

Why did Sentence case capitalise a word in the middle of my sentence?

Almost certainly because an abbreviation came just before it. Sentence case finds sentence starts with a simple rule - a full stop, exclamation mark or question mark followed by a space - and an abbreviation matches that pattern exactly. So 'approx. five apples' comes back as 'Approx. Five apples', and the same happens after 'e.g.', 'Dr.' and 'etc.'. Telling an abbreviation from a real full stop means understanding the words, which no character transformation can do. Decimals are safe, though: 3.50 has no space after the point, so it is never treated as a boundary.

It lowercased a name. Can I stop that?

Not automatically. Both lowercase and Sentence case have no way to know that 'london' is a place or that 'March' is a month rather than a verb - that requires understanding the text, not transforming it. Proper nouns are the one thing you will always have to put back by hand, so scan for them before you paste the result anywhere that matters.

What about camelCase or snake_case?

Not here. Those are programming identifier conventions rather than text cases, and they need to break words apart and rejoin them differently rather than just changing letters. A URL slug is the closest thing this site offers to that shape.

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