`res.sendFile()`

Streams a file to the client, inferring Content-Type and supporting ranges.

Since Express 4 Spec ↗

Syntax

res.sendFile(path[, options][, callback])

Parameters

Name	Type	Required	Description
`path`	`string`	Yes	The absolute file path (or relative with `options.root`).
`options`	`object`	No	`root`, `maxAge`, `headers`, `dotfiles`, `acceptRanges`.
`callback`	`function`	No	`(err)` invoked when the transfer finishes or fails.

Returns

void — Streams the file response.

Examples

app.get('/', (req, res) => {
  res.sendFile('index.html', { root: './public' });
});

Output

Content-Type: text/html; charset=UTF-8

import { join } from 'node:path';

app.get('/docs/:name', (req, res) => {
  res.sendFile(join(import.meta.dirname, 'docs', req.params.name), (err) => {
    if (err) res.sendStatus(404);
  });
});

Notes

The path must be absolute unless you pass `options.root`. Without `root`, Express rejects paths containing `..` to block traversal; still validate filenames from user input. Sets `Content-Type`, `Last-Modified`, and ETag and supports range requests.