Thai language support in PHP: encoding, localization, and practical tips

Thai language support in PHP

Thai text in PHP requires careful handling of encoding, locale, and database settings to preserve data integrity and provide correct display.

Why Thai text poses challenges

Thai uses its own script and word boundaries; there are no spaces between words in traditional Thai, and characters may combine. For software, the main issues are encoding, storage, and locale-based operations like case-insensitive comparisons or sorting.

Encoding and Unicode basics

Always use UTF-8 for source files, database connections, and data storage. Save PHP files as UTF-8 (without BOM if possible). In MySQL/MariaDB, use utf8mb4 character set and utf8mb4unicodeci or utf8mb4_bin for safety.

PHP tools for Thai text

Enable and configure mbstring, iconv, and intl extensions. Example code:

// Ensure UTF-8 handling
mb_internal_encoding('UTF-8');
mb_http_output('UTF-8');
ini_set('default_charset', 'UTF-8');

Working with Thai in databases

When storing Thai text, use a UTF-8 capable column (utf8mb4_...). In PDO, set charset in DSN: mysql:host=...;dbname=...;charset=utf8mb4.

Locales and sorting

Use the intl extension for locale-aware operations; set locale to Thai: setlocale(LCCOLLATE, 'thTH.UTF-8'); or use Collator:

$coll = new Collator('th_TH');
echo $coll->getSortKey('ภาษาไทย');

Common pitfalls and tips

• Mismatch between browser, PHP, and database encodings causes garbled text.
• Avoid BOM in PHP files and data sources.
• Normalize text if needed; Thai uses combining characters; use NFC/NFKC where appropriate.
• Always test with real Thai data.

Conclusion

With proper UTF-8 handling, mbstring, and locale support, PHP can robustly handle Thai text across input, storage, and display.