By the end of this tutorial, you’ll capitalize the first letter of any string while keeping the rest unchanged using Lodash’s _.capitalize().
Call _.capitalize(string) with any text value.
Only index 0 changes; the remainder stays as-is.
Polish headings, names, and dynamic messages for display.
Understand when _.upperFirst is equivalent.
Handle empty strings and non-string edge cases safely.
Do not confuse with title case or full uppercasing.
_.capitalize()?_.capitalize() uppercases the first character of a string and leaves every other character exactly as it was. It does not lowercase the rest of the string or capitalize each word—that is the job of _.startCase().
Think of _.capitalize('hello, world!') as “make the first letter uppercase for display,” not “fix the entire sentence.”
Use it for greeting messages, form field previews, toast notifications, and anywhere you want a quick polish without restructuring the whole string.
Pass the string whose first character should be uppercased:
_.capitalize(string)string — the input text. Coerced to string if needed.import capitalize from "lodash/capitalize";
const original = "hello, world!";
const result = capitalize(original);
// -> "Hello, world!"| Task | Code pattern | Result |
|---|---|---|
| Basic capitalize | _.capitalize('hello') | Hello |
| Preserve rest | _.capitalize('iPhone rules') | IPhone rules |
| Empty input | _.capitalize('') | '' |
| First char only | _.upperFirst(str) | Same as capitalize for strings |
| Title every word | _.startCase(str) | Foo Bar style |
| All uppercase | _.toUpper(str) | ENTIRE STRING |
NoReturns a new string
Index 0First character only
_.upperFirst()Equivalent behavior
_.startCase()Capitalizes each word
Arguments to _.capitalize() and what they control:
string RequiredThe string to capitalize. Non-string values are coerced with String().
_.capitalize('hello')return value New stringA copy with the first character uppercased. The original string is unchanged.
// -> 'Hello'rest unchanged ImportantCharacters after index 0 keep their original casing and punctuation.
_.capitalize('hello WORLD')empty input Edge caseAn empty string returns '' without throwing.
_.capitalize('')For capitalizing every word in a phrase, use _.startCase(). For identifier-style names, use _.camelCase().
Practical _.capitalize() patterns with copy-ready code, sample output, and interactive Try It Yourself labs.
Capitalize the first letter while preserving the rest of the string.
Uppercase the first character of a casual greeting string.
import capitalize from "lodash/capitalize";
const original = "hello, world!";
const capitalized = capitalize(original);
console.log(capitalized);
// -> "Hello, world!"Only the h at index 0 becomes H. The comma, space, and lowercase world! stay the same.
Brand names and acronyms inside the string are not altered.
import capitalize from "lodash/capitalize";
const brand = "apple iPhone";
const display = capitalize(brand);
console.log(display);
// -> "Apple iPhone"Lodash does not lowercase or re-case words after the first character.
Show a polished label from raw user input in a dashboard header.
import capitalize from "lodash/capitalize";
const userName = "john_doe";
const heading = capitalize(userName);
console.log(heading);
// -> "John_doe"Great for quick display polish; pair with _.startCase if you need title-style formatting.
Safely call capitalize on empty input without errors.
import capitalize from "lodash/capitalize";
console.log(capitalize(""));
// -> ""Lodash returns early with an empty string—no error is thrown, which makes capitalize safe to call after optional user input.
Running capitalize on an already-uppercase first letter is harmless.
import capitalize from "lodash/capitalize";
const title = "Hello";
console.log(capitalize(title));
// -> "Hello"Uppercasing an already-uppercase first letter is a no-op for that character, so the output matches the input.
Compare with related string case helpers.
Pick the right helper for greetings, titles, or shout-case.
import capitalize from "lodash/capitalize";
import startCase from "lodash/startCase";
import toUpper from "lodash/toUpper";
const input = "hello world";
console.log(capitalize(input)); // -> "Hello world"
console.log(startCase(input)); // -> "Hello World"
console.log(toUpper(input)); // -> "HELLO WORLD"capitalize touches one character; startCase restructures words; toUpper uppercases everything.
_.capitalize() WorksLodash converts the input to a string if needed.
The character at index 0 is isolated for transformation.
That single character is converted to uppercase.
The rest of the string (index 1+) is appended unchanged.
A display-ready string with only the first letter uppercased.
_.capitalize() is equivalent to _.upperFirst() for strings._.startCase() for that.'' without throwing.lodash/capitalize for minimal bundle size._.capitalize() is a small but handy helper for polishing text in UI copy, notifications, and dynamic messages. One call, one character changed, zero surprises for the rest of the string.
When you need every word capitalized, switch to _.startCase(). For identifier-style names, use _.camelCase() instead.
_.capitalize()Use these points whenever you need a quick first-letter uppercase.
Only index 0 changes.
BasicsGreat for labels and toasts.
PatternFunctionally equivalent alias.
RelatedUse startCase for words.
CaveatImport lodash/capitalize.
Bundle_.capitalize() and _.upperFirst() are aliases in Lodash—same behavior, different name. For multi-word titles like “Jane Smith”, use _.startCase() instead of expecting capitalize to fix every word.
Open the Try It editor, run the examples, and experiment with your own strings.
6 people found this page helpful