Where do I put the generated config?

Save it as .prettierrc, .prettierrc.json, or a "prettier" key inside package.json at your project root. Prettier picks up the nearest config file automatically.

What does trailingComma "all" do?

It adds a trailing comma after the last element in arrays, objects, and function arguments, including function calls. This is the modern Prettier default and produces cleaner diffs.

Should I use tabs or spaces?

Either works with Prettier. Spaces render identically everywhere and are the more common default; tabs let each developer set their own visual width in their editor.

What is printWidth actually enforcing?

printWidth is a target line length, not a hard limit. Prettier tries to keep lines under this width but will exceed it when breaking the line would make the code less readable.

Do I still need to install Prettier?

Yes. This tool only generates the config file. Install Prettier itself with "npm install --save-dev prettier" and run it via a script or your editor's format-on-save integration.

Prettier Config Generator

Toggle Prettier formatting options and get a ready-to-use .prettierrc JSON file, with copy and download.

Formatting Options

Semicolons (semi)

Single quotes (singleQuote)

Use tabs, not spaces (useTabs)

Bracket spacing (bracketSpacing)

Tab Width

Print Width

Trailing Comma

Arrow Function Parens

End of Line

.prettierrc

package.json Scripts (optional)

"scripts": {
  "format": "prettier --write .",
  "format:check": "prettier --check ."
}

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Summary

Build a Prettier configuration file without memorizing every option name. Toggle semicolons, quote style, tab width, print width, trailing commas, bracket spacing, arrow parens, and line endings, and watch the .prettierrc JSON update as you go. Copy it straight into your editor or download the file and drop it in your project root.

How it works

Toggle semicolons, single quotes, tab usage, and bracket spacing on or off.
Set tab width and print width with the number inputs.
Pick trailing comma style, arrow function parens, and end-of-line format.
The .prettierrc JSON on the right updates automatically as you change options.
Click "Copy" to copy the config, or "Download" to save it as .prettierrc.

Use cases

Bootstrap a .prettierrc for a new JavaScript or TypeScript project.
Match a team's existing formatting style without guessing option names.
Compare tab-based versus space-based indentation before committing.
Generate a config to paste into package.json under a "prettier" key.
Standardize print width and trailing commas across a monorepo package.
Quickly test how ES5 versus all trailing commas look in the JSON output.

Frequently Asked Questions

Last updated: 2026-09-09 · Reviewed by Nham Vu