🔤 Proper Case (Name) Converter
By ToolNimba Editorial Team · Updated 2026-06-19
Enter one name per line to convert it to proper case.
This proper case converter fixes the capitalization of personal names. Paste a list of names, one per line, and it capitalizes each word the way names are actually written, not just blindly upper-casing the first letter. It keeps particles like van, de and von lowercase mid-name, handles Mc and Mac prefixes (McDonald, MacArthur), Irish O' surnames (O'Brien), hyphenated names (Smith-Jones) and Roman numeral suffixes (III, IV). Everything runs in your browser, so your data never leaves your device.
What is the Proper Case Converter?
Proper case (also called name case) means writing a name so each significant part starts with a capital letter, while small connecting words inside the name stay lowercase. It is the convention you see in print and on official documents: Mary O'Brien, Ludwig van Beethoven, Henry VIII. A naive capitalizer that simply upper-cases the first letter of every word gets the common cases right but mangles the interesting ones, turning "mcdonald" into "Mcdonald" instead of "McDonald", or forcing "van" to "Van" where it should stay lowercase.
Real names follow patterns that come from different languages and traditions. Dutch, German, French, Spanish and Italian surnames use particles such as van, von, de, della and du that are normally lowercase when they sit between the first and last name, but capitalized when they begin the name (for example, the surname Van Gogh at the start of a sentence). Scottish and Irish names use the Mc and Mac prefixes, where the letter after the prefix is capitalized: McDonald, MacArthur. Irish names also use the O' prefix, as in O'Connor and O'Brien. Hyphenated names capitalize each side of the hyphen, and generational suffixes written as Roman numerals (II, III, IV) stay in capitals.
No automatic tool can be perfect, because the same letters can be a particle in one name and a real syllable in another, and personal preference always wins (some families deliberately write Macdonald or de la Cruz a fixed way). This converter applies the most common rules and lets you toggle each one on or off, so you get a fast, sensible first pass that you can then eyeball and tweak. It is built for cleaning up lists: data imported in ALL CAPS, sign-up forms typed in lowercase, or a spreadsheet of mixed-case names that needs to look consistent.
When to use it
- Cleaning up a contact list or CRM export where names were entered in ALL CAPS or all lowercase.
- Standardizing names on certificates, name badges, invitations or membership cards before printing.
- Fixing names typed without capitals in a sign-up or checkout form before sending an email.
- Tidying a spreadsheet column of customer or student names so they display consistently.
How to use the Proper Case Converter
- Type or paste your names into the box, one name per line.
- Leave the options on for the rules you want (particles, Mc/Mac, Roman numerals, Irish O prefixes), or untick any you do not need.
- Read the corrected names in the result box, which updates as you type.
- Check the output by eye for any unusual names, then press Copy to grab the cleaned list.
Formula & method
Worked examples
Converting "JOHN MCDONALD" with the Mc/Mac rule on.
- Split into words: JOHN, MCDONALD.
- JOHN is a plain word: capitalize first letter, lowercase the rest, giving John.
- MCDONALD starts with "mc" and is longer than 2 letters, so apply the Mc rule.
- Keep the prefix as Mc, then capitalize the remainder "donald" to Donald.
- Join: John McDonald.
Result: John McDonald
Converting "ludwig van beethoven" with the particle rule on.
- Split into words: ludwig (first), van (middle), beethoven (last).
- ludwig is the first word, so capitalize normally to Ludwig.
- van is in the particle list and is neither first nor last, so it stays lowercase as van.
- beethoven is the last word, so capitalize normally to Beethoven.
- Join: Ludwig van Beethoven.
Result: Ludwig van Beethoven
Converting "mary o'brien-smith iii" with all rules on.
- Split into words: mary, o'brien-smith, iii.
- mary capitalizes to Mary.
- o'brien-smith contains a hyphen, so split into o'brien and smith.
- o'brien matches the Irish O rule, giving O'Brien; smith capitalizes to Smith; rejoin with the hyphen as O'Brien-Smith.
- iii is a Roman numeral, so it becomes upper-case III.
- Join: Mary O'Brien-Smith III.
Result: Mary O'Brien-Smith III
Common name-casing rules this tool applies
| Rule | Input | Output |
|---|---|---|
| Plain word | jOHN | John |
| Mc prefix | mcdonald | McDonald |
| Mac prefix | macarthur | MacArthur |
| Irish O' prefix | o'connor | O'Connor |
| Lowercase particle (mid-name) | ludwig van gogh | Ludwig van Gogh |
| Hyphenated surname | smith-jones | Smith-Jones |
| Roman numeral suffix | henry viii | Henry VIII |
Particles kept lowercase when they fall mid-name
| Origin | Example particles |
|---|---|
| Dutch | van, van der, den, ter, ten |
| German | von, von der, der |
| French | de, du, la, le, des |
| Spanish / Portuguese | de, del, da, dos, la |
| Italian | di, da, della, del |
| Arabic (transliterated) | al, bin, ibn |
Common mistakes to avoid
- Expecting every particle to stay lowercase. A particle like van or de is only lowercased when it sits between the first and last name. When it starts the name (for instance Van Gogh at the beginning of a list entry) it is capitalized, and this tool follows that rule by always capitalizing the first and last words.
- Trusting the tool with unusual or chosen spellings. Some families deliberately write Macdonald, MacKenzie, de la Cruz or DeAngelo in a fixed way. Automatic rules cannot know personal preference, so always scan the output and correct names a person spells their own way.
- Confusing name case with title case. Title case for headings lowercases short words like "of" and "the" everywhere. Name case is different: it focuses on surname particles and prefixes, and capitalizes the first and last parts. Do not use this tool to title-case article headlines.
- Running it on text that is not a list of names. The converter assumes each line is one name and applies surname rules to every word. Pasting ordinary sentences can wrongly capitalize words like "Mac" or "Van" inside them. Use a sentence-case tool for prose instead.
Glossary
- Proper case (name case)
- Capitalizing a personal name so each significant part begins with a capital while small connecting particles stay lowercase.
- Particle
- A small word inside a surname such as van, de or von that links name parts and is usually lowercase mid-name.
- Mc / Mac prefix
- A Scottish or Irish surname prefix meaning "son of", where the letter after the prefix is capitalized, as in McDonald and MacArthur.
- O' prefix
- An Irish surname prefix meaning "descendant of", written with a capital O, an apostrophe and a capitalized stem, as in O'Brien.
- Roman numeral suffix
- A generational marker such as II, III or IV written after a name and kept fully capitalized.
- Title case
- A heading style that capitalizes major words and lowercases minor words like "of" and "the"; different from name case.
Frequently asked questions
What is proper case for a name?
Proper case (or name case) capitalizes each meaningful part of a personal name while keeping small surname particles lowercase. For example, "ludwig van beethoven" becomes "Ludwig van Beethoven" and "mcdonald" becomes "McDonald", which a plain capitalizer would not get right.
How does the tool handle McDonald and MacArthur?
When the Mc/Mac option is on, a word starting with "mc" is written as Mc followed by a capitalized stem (McDonald), and a word starting with "mac" becomes Mac followed by a capitalized stem (MacArthur). You can turn this off if a name should not use the prefix rule.
Why does "van" stay lowercase in some names?
Particles such as van, de and von are conventionally lowercase when they sit between the first and last name, as in Ludwig van Beethoven. The tool keeps them lowercase only in the middle and capitalizes them when they are the first or last word of the line.
Does it handle hyphenated and Irish names?
Yes. Hyphenated names are capitalized on both sides of the hyphen (Smith-Jones, Anne-Marie), and Irish O' surnames become O'Brien or O'Connor with the O option on. Apostrophe names like D'Angelo are capitalized on each side of the apostrophe too.
What about Roman numeral suffixes like III?
With the Roman numerals option on, a word that is a valid Roman numeral (such as II, III, IV or VIII) is kept fully capitalized, so "henry viii" becomes "Henry VIII" rather than "Henry Viii".
Is my data private?
Yes. The conversion happens entirely in your browser using plain JavaScript. Nothing you type is uploaded or stored anywhere, so you can safely paste lists of real customer or contact names.