Example 1 — Official: Lowercase Word
Uppercase only the first letter.
Lodash
console.log(_.upperFirst("fred"));
// 'Fred'How It Works
- First.
fbecomesF. - Rest.
redstays lowercase. - Result.
Fred. - Docs. Matches the official first example.
Lodash _.upperFirst() Method
Definition
Converts the first character of a string to uppercase and leaves everything else unchanged. Part of Lodash String (stable since 4.0.0 — not deprecated). Note: unlike _.capitalize, it does not lowercase the rest of the string.
Pass the string and options shown below. Check the return type before you chain another helper.
Syntax
Call _.upperFirst. Start with this line.
Lodash
_.upperFirst([string=''])| Call | What it does |
|---|---|
_.upperFirst([string='']) | Primary signature. |
_.upperFirst(string) | Transform or inspect a string. |
Prefer import upperFirst from "lodash/upperFirst" when you want a smaller bundle.
Library declarations
Lodash
_.upperFirst([string=''])Parameters
| Parameter | Description |
|---|---|
| string | Optional. Value to convert (default ''; non-strings are coerced) |
Return Value
| Return Value | Description |
|---|---|
| * | New string with first character uppercased |
Lodash Examples
Example 2 — Official: Already Uppercase
The rest of the string is not forced to lowercase.
Lodash
console.log(_.upperFirst("FRED"));
// 'FRED'How It Works
- First.
Fis already uppercase. - Rest.
REDis left alone. - Result. Still
FRED. - Docs. Matches the official second example.
Example 3 — vs _.capitalize
Same input, different rules for the remaining letters.
Lodash
var s = "fRED";
console.log(_.upperFirst(s)); // 'FRED'
console.log(_.capitalize(s)); // 'Fred'How It Works
- upperFirst. Only flips the first character →
FRED. - capitalize. First upper + rest lower →
Fred. - Pick. Use capitalize for title-style single words.
- Next. See
_.capitalize.
Example 4 — vs _.lowerFirst
Opposite helpers for the first character.
Lodash
console.log(_.upperFirst("fred")); // 'Fred'
console.log(_.lowerFirst("Fred")); // 'fred'How It Works
- upperFirst. Raises the first letter.
- lowerFirst. Lowers the first letter.
- Rest. Both leave the remaining characters alone.
- Next. See
_.lowerFirst.
Example 5 — Start a Sentence
Capitalize the first letter without touching later words.
Lodash
console.log(_.upperFirst("hello WORLD"));
// 'Hello WORLD'How It Works
- First.
h→H. - Rest.
ello WORLDis unchanged. - Use. Handy when later casing must stay intact.
- Tip. For title case words, try
_.startCase.
Compatibility
Browser & Runtime Support
_.upperFirst is a Lodash String helper available since 4.0.0. It runs anywhere Lodash runs — modern browsers (via CDN or bundle) and Node.js / Bun / Deno with npm install lodash.
Stable · Lodash 4.x
_.upperFirst()
Available in [email protected] full builds and the lodash/upperFirst modular import. Works in evergreen browsers and current Node LTS when Lodash is installed.
100% With Lodash 4.x
Google Chrome Supported · Desktop & Mobile
Full supportMozilla Firefox Supported · Desktop & Mobile
Full supportApple Safari Supported · macOS & iOS
Full supportMicrosoft Edge Supported · Chromium
Full supportInternet Explorer No native support · Use a polyfill
PolyfillOpera Supported · Modern versions
Full supportSamsung Internet Supported · Android
Full supportBun Supported · JavaScript runtime
SupportedDeno Supported · JavaScript runtime
SupportedNode.js Supported · Server runtime
SupportedAndroid WebView Supported · Modern WebView
Full support_.upperFirst Since 4.0.0
Bottom line: Safe for production once Lodash is on the page. Prefer import upperFirst from "lodash/upperFirst" for smaller builds. Native: string.charAt(0).toUpperCase() + string.slice(1).
Frequently Asked Questions
_.upperFirst([string='']) converts the first character of string to uppercase and leaves the rest unchanged. Official: _.upperFirst('fred') → 'Fred'.
_.upperFirst only uppercases the first character. _.capitalize uppercases the first character and lowercases the rest — so 'FRED' stays 'FRED' with upperFirst, but becomes 'Fred' with capitalize.
_.toUpper uppercases the whole string. _.upperFirst changes only the first character.
No. Strings are immutable. _.upperFirst always returns a new string.
_.upperFirst('') returns ''. Non-strings are coerced to strings first.
Use import upperFirst from "lodash/upperFirst" or require("lodash/upperFirst"). Full build: import _ from "lodash" then _.upperFirst.
Next: _.words()
Split a string into an array of words.
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