Bidirectional Languages, Everything You Need To Know

Why Localization Matters and How to Implement It?

Ever heard or read “Bidi languages” term? It refers to “Bi-directional Languages”,
which contains both right-to-left (RTL) and left-to-right (LTR) writing orders.
This leads to a mixed direction of text segments described as “Bidirectional.”

Mistakenly, people always think that only Arabic and Hebrew languages are bidirectional.
However, it is not about the language, it is about the script/alphabet the language uses.
A bidi language is any language written using:

• Arabic (Perso-Arabic) script such as Arabic, Persian (Farsi), Urdu, Uyghur, Pashto, Kurdish (Sorani), Punjabi and Sindhi languages.
• Hebrew Script such as the Hebrew and Yiddish languages.

Common Features

• These languages are written from Right to Left.
• Supporting BiDi means supporting 10+ languages.

Bidi Support

It is not about Right alignment, full mirroring and definitely not translation.
It’s all about expected behavior; “Bidi support is the ability to input and display text layout
in either right-to-left (RTL) or left-to-right (LTR) order, considering the alignment.”

That’s why some computer programs or platforms fail to display bidirectional text correctly.
For example, some interfaces show:

• Wrong reading order (all text reads from Left to Right).
• Left aligned.

While proper bidi features include:

• Correct RTL and LTR reading order.
• Right alignment.

Flipping and Mirroring

Bidi users’ thinking, understanding and surrounding digestion often goes from right to left,
but that does not mean you have to flip or mirror everything.
Some icons, symbols and shapes stay as is.

To be flipped/mirrored:

• Back and Forward icons
• Arrows
• Images location (not the images themselves)
• Columns start from the right
• Start buttons
• Horizontal progress bar
• Rating
• Page number
• Circular progress indicators
• Percent symbol position

Not to be flipped/mirrored:

• Check marks
• Media Player control buttons
• Images themselves
• Clock digits or icons
• Mouse cursor direction
• Phone numbers

Numeral System

Mainly, there are two numbering systems for Arabic:

• Original Arabic digits (1, 2, 3, …) – used more in Gulf area.
• Hindi digits – used more in other Middle East countries.

Arabic numbers are also used in Hebrew.
In all cases, numerals are written and read from left to right.

Punctuation

Arabic punctuation has slightly different shapes that follow RTL writing.
Functions are similar to English, but mistakes often happen.

Calendars

• Hijri Calendar
• Gregorian Calendar (widely used)
• Hebrew Calendar

Editing Tips

• Arabic/Hebrew keyboards allow toggling typing direction.
• Cursor movement and text selection should respect logical and physical order.

Localization Tips

• Arabic text expands ~30% compared to English.
• Arabic words cannot be split across lines; Kashida is used for justification.
• Persian has 4 more letters than Arabic.
• MSA is the standard written Arabic; spoken dialects vary by region.

Arabic Translation Tips:

• Translate according to subject gender.
• Highlight words with quotation marks (no capitalization).
• Dual form differs from plural and should be handled carefully.
• Regular QA tools don’t spot bidi issues for neutrals.

At Saudisoft, we have developed a quality check tool to easily detect and fix bidi issues,
ensuring top-quality localization.

Tips for I18n

• Test on modern bidi-enabled platforms (OS).
• Assess localizability: concatenated text, images, etc.
• Create pseudo-builds.
• Invite native experts early in the process for validation.

Why Text Editor Internationalization (i18n) Matters

Modern software development demands robust text editor internationalization (i18n) RTL bidirectional text support to serve a truly global user base. As applications reach users worldwide, editors must adapt not just their language strings, but their entire text-handling behavior to different scripts and reading directions.

The Challenge of RTL Support

One of the most difficult aspects of this process is proper RTL (right-to-left) support. Languages such as Arabic, Hebrew, and Persian require more than simple mirroring of the interface — the editor must correctly handle bidirectional text (bidi) rendering, where RTL script and embedded LTR elements (like code snippets, numbers, or English terms) coexist within the same line.

What Happens Without Proper Bidi Support

Without accurate bidirectional text support, several core functions can break down:

• Cursor movement becomes unpredictable
• Text selection behaves inconsistently
• Line-wrapping fails to follow natural reading order

These failures lead to a frustrating, error-prone editing experience for RTL-language users.

What a Well-Internationalized Editor Looks Like

A properly internationalized text editor should:

• Implement the Unicode Bidirectional Algorithm to correctly reorder mixed-script content
• Support RTL-aware UI layouts — menus, scrollbars, and toolbars that flip contextually
• Allow seamless switching between LTR and RTL input without corrupting text structure

The Bottom Line

For developers building multilingual applications, investing early in comprehensive text editor internationalization i18n RTL bidirectional text support — rather than retrofitting it later — is essential to delivering an editor that feels native and intuitive to users, regardless of their language or script direction.

Conclusion

Bidirectional languages localization can be tricky, from UI/UX to grammar and writing.
To be fully prepared for bidi clients, Saudisoft can guide and support with both
technical tools and linguistic expertise to meet audience expectations.