If you write in Arabic and have searched for "best AI writing assistant," you've seen the usual list: Grammarly, Jasper, Copy.ai, Wordtune, QuillBot. The problem is that none of them check Arabic grammar. Not "check it poorly" — they don't support it, and it's written in their own documentation for anyone who looks.
We reviewed the official support pages and documentation of fourteen tools and sorted them into three groups: the famous writing assistants, the tools built for Arabic from the ground up, and the general-purpose AI models. The gap between the groups is far wider than English-language reviews suggest.
Group one: five famous tools that don't check Arabic
Grammarly expanded its language support on March 11, 2026 to 22 languages — Turkish, Polish, Hindi, Vietnamese, and more. Arabic isn't among them. Paste Arabic text and you get translation only, no grammar or spelling checks. An independent test published by Truescho this year found Grammarly caught two of seven deliberate Arabic errors.
Jasper documents 34 workspace languages, from Bulgarian to Ukrainian. Arabic is entirely absent from the list.
Copy.ai is no longer the tool you remember: Fullcast acquired it on October 15, 2025 and repositioned it toward enterprise sales and revenue-operations teams. Its support site now redirects to Fullcast, and there's no published language list that mentions Arabic.
Wordtune accepts Arabic as input — but only outputs English. Its documentation is explicit: "you can input content in other languages, just note that the results will be in English." That's a translator, not an Arabic writing assistant.
QuillBot supports Arabic in its Translator only. The grammar checker works exclusively in English, German, Spanish, and French; the paraphraser covers 23 languages, none of them Arabic; and the summarizer, citation generator, and plagiarism checker are English-only.
The bottom line: if Arabic is your primary language, the five most-recommended tools in English reviews offer you nothing beyond translation.
Group two: Arabic-native tools — where the real work happens
Qalam.ai, from Mawdoo3, is the most complete tool in this group: Arabic and English grammar and spelling checks, automatic tashkeel (diacritization), tafqit (converting numbers to words for financial documents), and bidirectional translation. It runs as a browser extension for Chrome, Firefox, Safari, and Edge, as an add-in for Word and Outlook, inside Google Docs, and on iOS and Android. The company cites 400,000+ users and 18 billion words proofread, offers a free trial, and independent reviews put the paid plan around $12/month.
Sahehly, from Sakhr Software — one of the oldest names in Arabic software — focuses on Modern Standard Arabic (the language of media and official documents) and deliberately doesn't handle dialects. Its distinguishing feature is diacritization control: full tashkeel, case-ending-only, or mandatory-only — a distinction no general-purpose tool offers. Free up to 1,500 characters a day; paid plans go up to 107,000 characters a month. Available on the web, as a Chrome extension, and on iOS and Android.
ARWriter.ai is the cheapest in the group ($4.99/month with a trial) and combines proofreading, rephrasing, diacritization, summarization, and tone conversion. In Truescho's test it scored above 8/10 in five of six categories.
Alnnahwi.com is a context-aware Arabic grammar and spelling checker, free for short texts and social posts with a paid tier for more capacity; it cites 23,000+ users. Limited on rephrasing and summarization, but it covers the core need without a subscription.
WriteX, from Lisan, is the institutional option in this group: an Arabic-first writing assistant built for government, enterprise and media, flagging 12 error types with one-click fixes, enforcing your organization's own style guide as people type, offering tashkeel and rewriting, and integrating with Word, Outlook, browsers and Google — with sovereign-cloud or on-premises deployment. Lisan cites adoption by 24+ government entities; you can start free.
Group three: ChatGPT, Claude, Gemini, and HUMAIN
The general-purpose language models understand Arabic well — far better than the famous writing assistants. But "understands" and "checks grammar accurately" are different things. Truescho's test found ChatGPT misses hamza and case-ending errors even while producing generally sound Arabic prose.
A separate 2026 test published by KuwaitAI focused on the gap between Modern Standard Arabic and Gulf dialect: Claude led on dialect and cultural-context understanding with the lowest hallucination rate, ChatGPT was strong on formal Arabic but weaker on Khaleeji, and Gemini comprehends well but defaults to an overly formal tone better suited to official documents than everyday content.
HUMAIN Chat is the local exception: launched August 25, 2025 by HUMAIN, the Public Investment Fund's AI company, running on ALLaM 34B developed with SDAIA. It supports voice input in multiple Arabic dialects and switching between Arabic and English within a single conversation, and is hosted entirely inside Saudi Arabia. The one limitation at the time of writing: it's available in Saudi Arabia only, with regional expansion promised.
What almost everyone fails at
- Hamza: the most common error in Arabic writing and the most ignored by general tools. Even ChatGPT misses it.
- Case endings (i'rab): only caught by tools actually built on Arabic grammar rules — Qalam, Sahehly, Alnnahwi.
- Tashkeel: the famous tools don't know it exists. General models approximate it. Only Arabic-native tools offer controlled diacritization options.
- Dialects: Sahehly ignores them by design (MSA only); Claude and HUMAIN handle them best.
- Mixed Arabic/English text: more a rendering problem (text direction) than a language one, and no tool on this list fully solves it.
So which one should you actually use?
- You write in MSA for work or publishing and want real proofreading: Qalam. Broadest platform coverage and the most complete feature set.
- You need precise diacritization (educational, Quranic, poetic content): Sahehly, for its three tashkeel modes.
- Tight budget: Alnnahwi free for short texts, or ARWriter under $5.
- An organization or government body needing a shared style guide and Saudi-hosted deployment: WriteX from Lisan.
- You write in Gulf dialect or marketing copy with a local voice: Claude, or HUMAIN Chat if you're in Saudi Arabia — then run the result through Qalam for a final check.
- You already use Grammarly or QuillBot: keep them for English. For Arabic they won't help.
We'll update this guide if any of the five famous tools adds real Arabic grammar support, or if HUMAIN Chat expands beyond Saudi Arabia — those are the two changes that would actually move the recommendations above.