Reading and Writing Files

Read a file

Prefer promise-based fs/promises with async/await.

import { readFile } from "fs/promises";

const text = await readFile("notes.txt", "utf8");
console.log(text);

Write a file

Creates the file if missing, or overwrites by default.

import { writeFile } from "fs/promises";

await writeFile("out.txt", "Hello from Node\n", "utf8");

Check existence carefully

Use access or handle errors from read/write. Avoid race-prone exists patterns in servers.

import { access } from "fs/promises";

try {
  await access("notes.txt");
  console.log("Found");
} catch {
  console.log("Missing");
}

Paths matter

Relative paths are relative to the current working directory (where you ran node), not always the script file.