What is a right-to-left language (RTL)?

Right-to-left languages are written and read from right-to-left, and localization for billions of these native speakers is a must for any business intending to truly go global.

Localization for RTL languages should definitely be planned for in the early stages of product design and kept in mind that it involves more than just text translation. Spatial design changes are necessary when localizing for RTL languages (including navigation, visuals, general layout, numerics, etc).

Enabling Unicode Bidi (or bidirectional script support) should be on your to-do list at the very beginning of the product development process.

Basic information about RTL languages

Script or writing systems of languages can have a different direction of writing, reading and interpreting. While languages such as English, German and Spanish have the left-to-right direction, others are written and read from right to left or in different variants of vertical writing.

There are 12 languages with RTL writing systems, and most prominent examples include:

1. Urdu - official language in Pakistan and India, more than 101 million speakers

2. Hebrew - official language in Israel, 9 million speakers

3. Arabic - official language in 26 countries, with 310 million speakers

Just considering the sheer number of language speakers, it is obvious that localization into RTL languages provides exceptional opportunities for market expansion.

How to localize for right-to-left languages?

When it comes to RTL languages, it is important to take into account that they take up more horizontal space than left-to-right languages.

Additionally, although the characters are written right-to-left, numbers are still written in a left-to-right system - this is called bi-directional text. If you are considering to include a RTL language localization of your product, or languages such as Mandarin, Japanese or Korean in the future; be sure to enable bi-directional text.

Keep in mind that localization for RTL languages is not just a localization for writing, it is a localization that affects visual components as well. Make sure the sequence of your pictures, navigation, animations and illustrations is localized properly and adapted to the reader.

Bidi Unicode support

Bidirectional script support means that both writing scripts with different directions (left-to-right and right-to-left) are supported. Unicode’s bidirectional (or Bidi) support includes not just letters, but also numbers, formatting characters, special characters, paragraph and heading levels.

Unicode encoding standard differentiates 4 general types of characters:

1. Strong - strong characters have definite direction.

2. Weak - weak characters have a vague direction.

3. Neutral - neutral characters have direction depending on the full context of the content.

4. Explicit formatting - explicit formatting characters are special Unicode sequences that direct the algorithm to modify its default behavior. They are further divided into: marks, embeddings, isolates and overrides.