req.acceptsCharsets() Function

req.acceptsCharsets() checks whether a given character set is acceptable to the client, based on the Accept-Charset header. It returns the first match, or false.

Note: Accept-Charset is largely obsolete now that UTF-8 is universal, but the method remains available for legacy or specific use cases.

Syntax

req.acceptsCharsets(charset)

Example

const express = require("express");
const app = express();
const PORT = 4700;

app.get("/legacy-export", (req, res) => {
    const charset = req.acceptsCharsets("ISO-8859-1", "UTF-8");
    res.send(`Using charset: ${charset}`);
});

app.listen(PORT, () => console.log(`Listening on ${PORT}`));

Use cases

• Supporting older clients with specific character-encoding requirements.
• Negotiating character sets for exported files (e.g. CSV downloads).
• Maintaining compatibility with legacy systems.