How does the tool decide a paragraph's direction?

By the first strong letter in the paragraph, the same rule the Unicode Bidirectional Algorithm and browsers use for unmarked text. Digits, punctuation and emoji are skipped because they carry no strong direction.

What does a neutral paragraph mean?

It contains no letters — only digits, punctuation, symbols or whitespace — so there is nothing to derive a direction from. The tool reports neutral instead of guessing.

Why does a phone number look out of place in Arabic text?

Numbers keep their own left-to-right order inside an RTL paragraph, so their visual position depends on the surrounding punctuation and any controls present. Both preview columns let you see the difference.

Does the analysis change my text?

No. It only reads and reports. The previews apply a direction attribute, which is presentational; the copy button gives you back exactly what you pasted.

Is the text I paste stored anywhere?

No. Direction detection and counting run entirely in your browser, and nothing is saved when you close the page.

RTL Text Tester

Your text

Paste or type text

Preview direction

Detected direction

Start typing above — the results update as you write.

Check how right-to-left text is detected and laid out: paragraph-by-paragraph direction, counts of RTL and LTR letters, and the same text rendered forced left-to-right and right-to-left side by side.

What is RTL Text Tester?

Right-to-left text is easy to write and surprisingly easy to break. The RTL Text Tester answers two questions that come up constantly when a document, a form or an interface mixes scripts: which direction will a browser pick for this paragraph, and what does the same text look like when it is forced the other way? It reports what it finds rather than rewriting anything, and the text you paste is never altered by the analysis.

Direction comes from the Unicode Bidirectional Algorithm's first-strong rule. The tool scans each paragraph and looks for the first character with a strong direction — a letter from an RTL script such as Arabic, Hebrew, Syriac, Thaana or NKo, or a letter from any other script. Everything before it is ignored, including digits, punctuation and emoji, because those are neutral or direction-inheriting for this purpose. A paragraph made only of numbers and punctuation has no strong letter at all, so it is honestly reported as neutral rather than guessed at.

The same first-strong logic is what a browser uses when text carries no explicit direction attribute, which is why the result here predicts how your text will behave in an unmarked container. Each paragraph is listed with its own detected direction, so a document that flips mid-page shows exactly which block is the cause. Counts of RTL letters, LTR letters and explicit control characters explain the mix: a paragraph that is mostly Latin letters with one Arabic word is a different layout problem from one that is mostly Arabic with a Latin brand name inside it.

The side-by-side preview shows the identical string rendered twice, once inside a right-to-left container and once inside a left-to-right one. Nothing about the characters changes — only the paragraph direction the browser applies — and the comparison makes punctuation drift obvious. A trailing full stop, a colon, a percentage sign or a phone number can appear to jump to the wrong end of a line in one direction and look correct in the other, which is usually the real bug behind a complaint about mixed-up text.

Testing a translated interface is the other common use. Paste the translated string with the English product name or version number in place, and check that the paragraph reads in the expected direction and that the Latin fragment sits where a reader expects it. Because the tool reports the count of existing control characters, you can also tell at a glance whether a string that behaves strangely arrived with invisible marks already inside it — a frequent leftover from copying out of a word processor.

The tool is deliberately non-destructive. It does not insert control characters, reorder characters or convert scripts; when you want to wrap a fragment explicitly, the Bidirectional Text Tester does that and shows the hex values of everything it inserts. Nothing is uploaded and nothing is stored, so pasted client text, unpublished manuscripts and internal strings stay in the browser.

One more use is checking pasted bidi text before it goes into a form, a template or a test fixture. If the direction is not what you expect, the paragraph list points at the block responsible and the letter counts show whether the cause is the script mix or a stray control character that arrived with the text.

How to use RTL Text Tester

Paste the text you want to check. Mixed Arabic, Hebrew and Latin in one paragraph is the interesting case.
Read the paragraph direction: right-to-left, left-to-right, or neutral when the block has no letters at all.
Scan the paragraph list to find which block flips direction and why the counts look the way they do.
Compare the two preview columns to see which way the punctuation and numbers sit most clearly.
Copy the text out unchanged — the analysis never edits what you pasted.

When to use RTL Text Tester vs related tools

Use it when you are laying out mixed-direction text and need to know how a browser will decide, or when a translation review has raised a question about a paragraph that seems to read backwards. The Bidirectional Text Tester takes the next step and wraps a specific fragment in Unicode controls when detection alone is not enough.

If text behaves oddly and you suspect the characters themselves rather than the direction, the Unicode Text Normalizer lists invisible and zero-width characters by position, which is where hidden marks left over from a copy and paste usually show up.

Privacy & Security

This tool runs entirely in your browser — no data ever leaves your device. There is no server round-trip, no upload, no logging, and no account required. Your input is processed locally using client-side JavaScript and is never stored, transmitted, or accessible to anyone else. When you close the tab, everything disappears.