Right-to-Left Languages vs Reversed Text

Languages such as Arabic, Hebrew, Persian and Urdu are written from right to left (RTL). That is not the same as reversing text, and confusing the two causes broken layouts and unreadable words.

How computers store RTL text

Text is stored in logical order: the order in which it is read and typed. For Arabic, the first character stored is the rightmost one on screen. The software then applies the Unicode Bidirectional Algorithm to display it right to left.

If you reverse the stored characters, you do not get correct RTL text; you get scrambled text that reads backwards in its own language.

Mixed-direction text

A sentence can mix RTL words with left-to-right numbers or English brand names. The bidirectional algorithm handles this automatically, but punctuation and parentheses near the boundary can appear in surprising places.

Connected scripts

Arabic and Urdu letters change shape depending on their position in a word. Reversing the characters breaks these connections, producing disconnected or incorrect letter forms. That is why a reverse text generator is meant for playful effects on scripts such as Latin, not for producing RTL text.

Tips for developers

• Set dir="rtl" and the correct lang attribute on HTML elements containing RTL content.
• Use CSS logical properties, such as margin-inline-start instead of margin-left, so layouts flip automatically.
• Never reverse strings to "convert" them to RTL.
• Test with real content from native speakers.

Tips for writers

When combining English and an RTL language in one document, keep each language in its own paragraph where possible, and preview the result on the device and app your readers will use.

Frequently asked questions

How does Arabic text direction work on computers?

Arabic text direction is right-to-left. Computers store Arabic text, Hebrew text and Urdu in reading order and display it right to left using the Unicode bidirectional algorithm, which also handles bidirectional text that mixes scripts.

What is Urdu text direction?

Urdu text direction is right-to-left, like Arabic, and Urdu letters join together. Reversing Urdu with a reverse text tool breaks the joined letters, so use the dir rtl attribute in HTML instead.