Last updated: August 28, 2026.
UTF-8 is the appropriate default for modern web pages because it represents all Unicode characters. ASCII is a compatible subset. ISO-8859-1 and Windows-1252 are older single-byte encodings that are often confused.
Quick comparison
ASCII covers 128 basic characters. ISO-8859-1 defines 256 code positions. Windows-1252 uses printable characters in the 0x80-0x9F range where ISO-8859-1 defines controls. UTF-8 uses one to four bytes and covers all Unicode code points.
| Encoding | Coverage | Best use |
|---|---|---|
| ASCII | Basic English and controls | Restricted protocols |
| ISO-8859-1 | Legacy Western European set | Known legacy imports |
| Windows-1252 | Legacy Windows Western text | Known legacy imports |
| UTF-8 | All Unicode | New pages, APIs, files, and databases |
Declare UTF-8 consistently
Save the file as UTF-8 and make the HTTP header, HTML declaration, database connection, and stored data agree. A declaration cannot repair bytes already saved in another encoding.
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>UTF-8 page</title>
</head>
<body>Unicode text belongs here.</body>
</html>Convert legacy data once
Identify the actual source encoding, keep a backup, and convert at the import boundary. Do not repeatedly guess and reconvert data at display time; that can turn a reversible mismatch into permanent corruption.
Reference: WHATWG Encoding Standard.
