Text
Case Converter
Paste any text and switch it between UPPERCASE, lowercase, Title Case and Sentence case. Title Case and Sentence case keep words you typed with capitals, such as iPhone and PDF.
Written by Jay Sudha · Published · Last updated
Press ⌘ Enter to run
21 words · 3 lines
Common uses
- Format headings and article titles
- Standardise spreadsheet columns
- Normalise email addresses and tags before comparing them
- Clean up shouty all-caps text before publishing
Limitations
- UPPERCASE capitalises every letter, including brand names, code and web addresses
- Title Case: names typed in lowercase get the general rule; check ones like McDonald or O'Brien
- Sentence case: ordinary names such as London are lowercased mid-sentence; abbreviations like e.g. read as sentence ends
Which case to choose
UPPERCASE suits headings and spreadsheet columns that must look uniform. lowercase normalises email addresses, tags and IDs, so values that differ only by case match when you compare or de-duplicate them. Title Case is for article titles and product names, and Sentence case turns shouty all-caps notes into readable prose before you publish them.
Every mode changes letter case only: spaces, punctuation, numbers, emoji and line breaks stay as they were. Choosing another mode converts the same text again, so you can compare the four results without pasting twice.
UPPERCASE: ß, Turkish i, and brand names
Every letter becomes its capital form using the standard Unicode case mapping, so accented letters convert too (é becomes É) and the German ß becomes SS. Spaces, punctuation, numbers, emoji and line breaks stay exactly as they were.
The mapping is the same whatever language your browser is set to, so a Turkish i becomes I rather than İ. Anything that should keep its lowercase (brand names like iPhone, code, web addresses) is capitalised along with everything else, so skim the result before you use it.
lowercase: where it surprises people
Every capital letter becomes lowercase using the standard Unicode case mapping, and nothing else changes: spacing, punctuation, numbers and line breaks stay as they were. That makes it useful for normalising email addresses, tags or IDs before you compare or de-duplicate them.
The mapping ignores your language settings. A Turkish capital İ lowercases to i followed by a combining dot, which can look odd, and deliberate capitals (acronyms, names, brand names) are lowercased too.
Title Case: where the rules slip
Each line is treated as its own title. The first and last word of a line are always capitalised, and so is the first word after a colon, a full stop, a question or exclamation mark, or a dash, where a subtitle usually starts. Short words (a, an, and, as, at, but, by, for, if, in, nor, of, on, or, per, so, the, to, up, via, vs, yet) are lowercase everywhere else, and hyphenated words are handled part by part, so step-by-step becomes Step-by-Step.
Words you typed with capitals are left as they are, so iPhone, FormatOS, PDF and NASA survive; only text written entirely in capitals is treated as shouting and lowered first. Contractions and accented words are handled properly (don't becomes Don't, naïve becomes Naïve), but a name you typed in lowercase gets the general rule, so o'brien comes back as O'brien, not O'Brien. Check names and non-English words by hand.
Sentence case: what it cannot know
The converter lowercases everything except words you wrote in capitals or with a capital inside them, then capitalises the first letter of your text, of every line, and of each sentence after a full stop, question mark or exclamation mark, looking past closing quotes and brackets. The pronoun I, including I'm and I'll, is capitalised too. Text written entirely in capitals is lowered completely, so shouting becomes readable.
It has no dictionary, so ordinary names and places end up lowercase mid-sentence and need fixing by hand, while a word you typed in capitals for emphasis stays in capitals, which is how acronyms survive. Abbreviations such as e.g. or Dr. are treated as sentence ends, so whatever follows them is capitalised as if a new sentence had begun.
Frequently asked questions
No. Every mode changes letter case only; spacing, punctuation, numbers and line breaks are preserved exactly.
Yes. It uses the standard Unicode case mapping, so accented Latin letters and other cased scripts such as Greek and Cyrillic convert correctly. The mapping does not change with your language settings, so in UPPERCASE a Turkish i becomes I, not İ, and in lowercase İ becomes i with a combining dot.
Articles, short conjunctions and short prepositions (a, an, the, and, but, or, for, of, on, in, to, by, at, as, via, vs and a few others) stay lowercase inside a title. They are capitalised when they start or end a line, or start a subtitle after a colon.
Title Case and Sentence case keep every word you typed with a capital inside it or in all capitals, so iPhone, FormatOS, PDF and NASA come through unchanged (unless the whole text is in capitals). There is no dictionary, though: a name typed in lowercase gets the general rule in Title Case (check mcdonald or o'brien), and Sentence case lowercases ordinary names such as London mid-sentence. UPPERCASE and lowercase change every letter, brand names included.
Lowercasing normalises values like email addresses or tags so duplicates that differ only by case match up during comparison or deduplication.
Yes. Sentence case turns shouty, all-caps text into clean sentence-cased prose, and Title Case does the same for headings: text written entirely in capitals is lowered first in both modes.
No. Every mode runs entirely in your browser and nothing is stored.
Related text tools
Tool last reviewed: September 27, 2026 · Report a problem