Why does right-to-left text break?
Unicode guesses the direction of a paragraph from the first strongly directional character in it. If your sentence opens with a number or an English word — «2.4 نسخهٔ جدید» or «Notion را نصب کنید» — the whole line is treated as left-to-right.
Full stops, commas, brackets and question marks are neutral: they have no direction of their own and borrow it from whatever surrounds them. That is why the final full stop jumps to the front of the line, brackets flip, and the order of numbers and English words looks shuffled.
Your text is not corrupted. The app you paste into simply does not know that this line should run right to left. This tool supplies that missing information as a few invisible control characters.
What gets fixed
- Line direction is locked with the invisible
RLEandPDFmarks. - Arabic letters in Persian text:
يandكbecomeیandک. Arabic and Hebrew text is never touched. - Punctuation:
, ; ? %become، ؛ ؟ ٪in Arabic-script text. - Broken half-spaces: duplicated, stranded at the ends of a line, or stuck to an ordinary space.
- Stray characters: kashida, unusual spaces, and control marks left over from earlier copies.
- Number signs:
-5and+12no longer flip. - Blank lines survive — the classic Instagram caption problem.
- Native digits are optional, and switching them off puts the original digits back.
Links, email addresses and English words are left alone. An address like rtlfix.app/fa or a code like SAVE20 comes out byte for byte identical, so Telegram and Instagram still recognise it as a link.
Where it helps
Anywhere you drop text into a container whose direction you do not control: Instagram captions and bios, Telegram and WhatsApp messages, YouTube descriptions, web forms, file names, SMS, email, and Word or Google Docs files whose default language is English.
Where it will not help
Apps with no bidirectional support at all — standard Photoshop and Illustrator, After Effects, CapCut, most game engines and subtitle tools — ignore these marks entirely. There the letters come out disconnected or reversed, which is a text-shaping problem rather than a direction problem. This tool does not fix that case.
Common questions
The text looks exactly the same. Did anything happen?
Direction marks are invisible characters, and this page is already laid out correctly, so you will not see a difference here. The difference shows up when you paste into the app you are writing for. The counter below the box tells you how many marks were added.
Does this add characters to my text?
Yes — two invisible characters per line. They never display or print, but they do count towards character limits, which is worth knowing if you are writing an SMS or anything with a strict limit.
Is my text uploaded anywhere?
No. Everything runs inside your own browser and no text is sent to a server. Once the page has loaded it works offline.
Will it change my letters?
Only in Persian, Urdu and Kurdish text, where the Arabic ي and ك are the wrong letters and get corrected. Arabic and Hebrew text keeps every letter exactly as it was, and in Pashto the ي is preserved because it is a letter in its own right.
Which languages does it work with?
Arabic, Hebrew, Persian, Urdu, Pashto and Kurdish. The script of each line is detected separately, so a document that mixes them is handled line by line.