🚧 This document is a work in progress.
Internationalization (i18n) and localization (l10n) involve numerous intricate details. This checklist serves as a reference for planning during the software design phase. However, it provides only a high-level overview. Since different countries and regions have unique requirements and standards, this document does not cover specific implementation details. Instead, it highlights key considerations to keep in mind when designing for international audiences.
Although UTF-8 is widely adopted, some platforms may not support it by default and instead use their own encoding schemes, such as ISO 8859-1, GBK, or Big5. Have you accounted for this in your application's character processing? Does your platform support displaying the required character sets, including Latin, ideographic, Cyrillic, Thai, and others?
In cases where certain character sets are unsupported, do you need a transcription system? For example, some Unix-based systems only support the ASCII character set and cannot display Cyrillic characters, requiring transliteration into Latin script.
A country or region may have multiple official languages or dialects. For example, Singapore recognizes English, Chinese, and Malay, while Hong Kong uses both Cantonese and English. Have you accounted for these linguistic variations?
Additionally, a single language may have multiple regional variations. For instance, Arabic as spoken in Saudi Arabia differs significantly from that used in the United Arab Emirates. Likewise, spelling and pronunciation vary between British English, Australian English, and American English.
Certain expressions or phrases may have region-specific variations that need careful translation to avoid sounding unnatural or inappropriate. For example, in Arabic-speaking regions, formal texts often include religious phrases like "Allahu Akbar" ("Allah is great"). In Japan and South Korea, appropriate honorifics should be used based on social and contextual factors.
Have you ensured that your UI properly supports RTL languages such as Arabic and Hebrew?
Different languages have different line-breaking rules. For example, Chinese and Japanese do not use spaces to separate words, while Thai requires special segmentation rules. Does your layout handle these differences correctly without causing layout thrashing?
Does your application support various input methods, such as on-screen keyboards and IMEs for Chinese, Japanese, and Korean text entry?
Keyboard layouts vary by region. Common layouts include QWERTY, QWERTZ, and AZERTY, and even within the same language, there may be differences. For example, the U.S. uses a standard QWERTY layout, while the U.K. has a slightly different variation. See more details.
When designing shortcut keys, ensure they remain accessible and intuitive across different keyboard layouts.
Sorting rules vary between regions. English-speaking countries typically use dictionary order based on item titles, while in mainland China, sorting by Pinyin is common. Hong Kong sorts by stroke count, whereas Taiwan follows Bopomofo order.
Moreover, alphabetical orders differ across languages, affecting sorting logic. Ensure your sorting algorithm accounts for these regional differences.
Which date format is used in your target regions? Is it DD/MM/YYYY, YYYY/MM/DD, or MM/DD/YYYY?
Are month names written as numbers or spelled out? Do you need to account for daylight saving time adjustments?
Different regions have unique numerical formatting and measurement units.
- The U.S. and U.K. use a comma (
1,000,000) as a thousand separator and a dot (1.5) for decimals, whereas Germany and France reverse this notation (1.000.000and1,5). - India groups numbers differently, using a 2-2-3 format:
10,00,000instead of1,000,000. - Measurement units vary: the U.S. uses inches, feet, and pounds, while most of the world follows the metric system.
Ensure your application can handle these variations dynamically.
If your application involves NLP features such as search, spell checking, or text analysis, are these adapted for different languages?
Have you prepared subtitles and translated resources for different languages? If your product supports live streaming or real-time interactions, do you provide interpretation services?
Have you accounted for cultural taboos and regional sensitivities?
- In monarchies like Thailand and Iran, criticism of the royal family is strictly prohibited.
- In Muslim-majority countries, certain animal symbols (e.g., pigs, donkeys) are considered inappropriate.
- Some regions restrict religious imagery; for example, Christmas-related elements are not permitted in Saudi Arabia and Yemen.
- Symbols can have vastly different meanings:
- The “OK” gesture (
👌) is positive in the U.S. but offensive in France, Germany, and Brazil. - The thumbs-up sign (
👍) may be considered sarcastic in Greece and parts of Latin America.
- The “OK” gesture (
To avoid unintended offense, research regional interpretations before including symbols in your UI.
What is the smallest currency unit in the target market? In China, it's 0.1 yuan, whereas in the U.S., it's 0.01 dollars.
Are currency exchange rates, transaction policies, and regional banking regulations accounted for?
How are large amounts displayed? In China, amounts may be written in uppercase Chinese characters, whereas English uses full word spelling.
Have you optimized content delivery networks (CDNs) for different regions to ensure low-latency performance?
Are there specific compliance or data protection laws that need to be followed, such as GDPR in Europe or PIPL in China?
Have you considered regional legal requirements related to software distribution, content moderation, and user privacy? For example, the European Union has very strict privacy legislation.
Have you accounted for accessibility standards?
- Different countries use different Braille systems and sign languages.
- Screen readers and assistive technologies should be tested across various locales.