`fs.readFile()`

Asynchronously reads the entire contents of a file.

Since Node 10 (fs/promises) Spec ↗

Syntax

await readFile(path[, options])

Parameters

Name	Type	Required	Description
`path`	`string \| Buffer \| URL \| integer`	Yes	The filename or file descriptor to read.
`options`	`object \| string`	No	An encoding string (e.g. `'utf8'`) or an object with `encoding`, `flag`, and `signal` (an AbortSignal) properties. With no encoding a Buffer is returned.

Returns

Promise<string | Buffer> — Resolves with the file contents.

Examples

import { readFile } from 'node:fs/promises';

const text = await readFile('./config.json', 'utf8');
console.log(JSON.parse(text).port);

Output

import { readFile } from 'node:fs/promises';

const buf = await readFile('./logo.png');
console.log(buf.length, 'bytes');

Output

20480 bytes

Notes

Reads the whole file into memory; for large files use `createReadStream`. Always pass an encoding when you want a string, otherwise you get a Buffer. The callback API (`fs.readFile`) is the older form; prefer the promises API shown here.