What is the Arabic diacritics (tashkeel) tool?
This tool adds Arabic diacritical marks automatically: fatha, damma, kasra, sukun, shadda and tanween. Paste ordinary unvowelled Arabic text and get it back fully vowelled within seconds, then fix any word with a single click. The engine combines two neural networks: a fast one we trained on more than two million diacritized words from the open Tashkeela corpus (classical texts), and the open-source libtashkeel model, trained mainly on Modern Standard Arabic. You get a draft instantly, then the deeper model refines it within seconds, all inside your browser.
How to use it
- Type or paste your text (up to 30,000 characters).
- Choose a diacritization level, then click “Add diacritics” (or press Ctrl + Enter).
- Check the words with an orange wavy underline: these are the ones the engine was least confident about.
- Click any word to open the editor: pick a letter, then the right mark. Each mark shows the engine’s own probability to guide you.
- If the same word appears several times, use “Apply to every occurrence” to fix them all at once.
- Copy the result, download it as a TXT file, or send it back to the input box to keep editing.
Diacritization levels
| Level | What it adds | Best for |
|---|---|---|
| Full | Every mark, including word endings (grammatical case) | Teaching material, speeches, children’s books |
| Word structure only | Marks inside the word, not on its last letter | General texts where you want to remove ambiguity; this is the most accurate level |
| Case endings only | The last letter’s mark and tanween | Grammar (i‘rab) exercises |
| Shadda & tanween only | Light marking | Titles and designs that need minimal vowelling |
Switching levels is instant and keeps your manual corrections.
Manual diacritization
Want to place the marks yourself (for practice, or for a text you need to control exactly)? Paste it and click “Manual diacritics” instead of the automatic option. The text appears with no added marks and the editor opens on the first letter:
- Pick a mark (fatha, damma, kasra, sukun, tanween…) or toggle shadda; the editor moves to the next letter, then to the next word.
- With an Arabic keyboard you can type the marks directly (Shift + the vowel keys), move with the arrow keys and clear a mark with Backspace.
- Words you have marked are underlined in green so you can see your progress.
You can also type in the box itself using the marks bar below it: place the cursor after a letter and click a mark to add or replace it.
How accurate is it?
We tested the tool on texts the engines never saw during training. Here are the results as measured:
| Text type | Correct letters | Words with correct structure | Fully correct words (incl. ending) |
|---|---|---|---|
| Modern Standard Arabic (articles and news, about 28,000 words) | 94.1% | 89.4% | 79.5% |
| Classical texts (about 42,000 words) | 93.8% | 88.1% | 81.3% |
In other words, about 9 words out of 10 get a correct internal structure; the figure is lower once the final mark is counted, because case endings depend on the word’s role in the sentence. That is why the tool highlights doubtful words for you, and why we recommend reviewing endings in important texts.
Standard Modern or Classical Arabic prose works best. Foreign proper names, dialect words and rare modern terms may need manual correction.
Tips for better results
- Write hamzas correctly: إلى, أن, إن instead of الى, ان helps the engine a lot.
- Pre-mark ambiguous words: if a word can be read several ways, mark it yourself and keep “Keep the marks already in the text” on: your marks stay untouched and the engine completes the rest.
- Use punctuation: commas and full stops help the engine see sentence boundaries.
- Start with highlighted words: they account for most of the errors.
A note on the Qur’an and religious texts
Don’t rely on any automatic diacritization for Qur’anic verses or hadith. Copy them, already vowelled, from a verified mushaf or trusted source: Qur’anic orthography follows its own rules that this tool does not cover.
Who is it for?
- Teachers and parents preparing vowelled reading and dictation texts.
- Students and learners of Arabic as a foreign language who want to read correctly and understand word patterns.
- Speakers, imams and voice-over artists who need to avoid pronunciation mistakes.
- Designers and content writers vowelling titles and quotes.
Your privacy
The engine files (about 2 MB) are downloaded once, then everything runs inside your browser: your text is never sent to a server. Your last text is kept only on your device so you find it when you come back; the “Clear” button deletes it.