IELTS Mentor AI vs Writing9 for IELTS Writing (2026)

Writing9 and IELTS Mentor AI both let you submit an IELTS Writing answer and get it marked by software against IELTS-style criteria. After that they part ways: one is a website that returns an overall band score and a report on each essay you paste in, the other is an installed app for all four skills that returns a band range per criterion and tracks the errors behind it. This page sets the two side by side using only what each product says about itself, with the dates we read it.

We make IELTS Mentor AI. Every fact about Writing9 below comes from its own site, quoted with the date; check its current pages before you decide.

What Writing9 says it is

Its homepage, read on 15 October 2026, is titled “Check your IELTS essay online.” and says: “Writing9 checks your writings and shows what you did well and what you can improve.” It promises that you “Know your band score in seconds” and “See exactly how to improve”, and its FAQ answers “What tasks can I check?” with: “You can check letters from Task 1 General, charts from Task 1 Academic and essays from Task 2 General/Academic.” A page for the checker adds: “Check as many essays as you want”, “Estimate your band score before taking the real test” and “Use the service from any device”.

Its demo page shows the editor: a topic box with a “Get a random question” button, a “Start Timer” button at 40:00, a live word and paragraph count, and an “Overall Band Score” with four headings beneath it: “Coherence and Cohesion”, “Lexical resource”, “Grammatical Range” and “Task Achievement”. The homepage lists what a plan includes: instant feedback, “Highlighting & analysing mistakes”, an “Advanced grammar checker”, “Weakness discovery”, “Personalized suggestions” and an “Ideas and vocabulary generator”. The site also carries topic lists and sample essays by band, and bonus tools for plan members, among them a Speaking simulator and Listening video practice.

On how close its score is to the exam, its FAQ says: “Our service is designed to provide a scoring estimation based on IELTS standards, but the final score you get on the actual IELTS exam might be slightly different due to various factors, including examiner’s discretion.” Its footer says it is “not affiliated, approved or endorsed by the University of Cambridge ESOL, the British Council, and IDP Education Australia.” We found no App Store or Google Play listing and no store badge. Writing9 shows its plans on its own homepage; we do not repeat them here.

What IELTS Mentor AI is

IELTS Mentor AI is a paid iOS and Android app for Academic IELTS practice in all four skills: an AI examiner marks Speaking and Writing on the four official criteria and reports a band range, full Reading and Listening tests are marked the moment you finish, and one Skill Map shows what to fix next.

For Writing that means Task 1 (Academic charts, graphs, tables and maps, and General Training letters) and Task 2, written in a timed editor with a live word count. Every answer comes back with a band for Task Achievement or Task Response, Coherence and Cohesion, Lexical Resource and Grammatical Range and Accuracy, as a range from a strict examiner’s reading to a lenient one, with an Examiner’s Summary. A Data Accuracy check compares a Task 1 report’s figures with the chart’s own data, so a misread chart is separated from a language mistake. Blocking Issues names the errors that recur across your writing with the band they cost, and Review Due brings back what you fixed before you would forget it. The interface is in English. It is not affiliated with IELTS, IDP, the British Council or Cambridge.

Where the two differ

Where you write. Writing9 opens in a browser tab, on a laptop or a phone, and asks for no installation; you paste or type the essay and check it. IELTS Mentor AI is installed from the App Store or Google Play and lives on the home screen, with a timed editor inside it. If you write essays at a desk on a keyboard, the browser takes nothing away; if your practice happens in gaps on a phone, an installed app is one tap away and can remind you.

How the score is reported. Writing9 gives one overall band score and, on its demo page, four criteria headings beneath it. IELTS Mentor AI gives a range for each criterion, from strict to lenient, because two examiners can read the same essay half a band apart; the range shows how close to a boundary you are and which criterion decides it. Neither is an official score, and Writing9 says the same of its own.

Task 1 and the chart. Both products say they take Task 1 charts and letters. Writing9’s pages describe a band score and a report on what to improve; they do not describe a check of a report against the figures in the chart. IELTS Mentor AI’s Data Accuracy check does that, which matters because Task Achievement in Task 1 depends on getting the data right.

What happens after the score. Writing9 describes “Weakness discovery” and “Personalized suggestions”, and a checker page promises you can “Watch your writing improve with every practice”. IELTS Mentor AI feeds every test into one Skill Map (articles, tenses, cohesion, collocations, prepositions, word form and more, each as a percentage), puts the error that appears in 80% or more of your responses at the top as the Skill to Fix First, and schedules Review Due with the FSRS algorithm. The difference is between a progress view for the writing you submit and a record shared with your other skills.

The other skills. Writing9 is built around Writing; its Speaking simulator and Listening video practice are listed as bonuses for plan members, and we found no Reading feature. IELTS Mentor AI marks Speaking on the four criteria across the full three-part test, and runs full Academic Reading papers and four-part Listening tests, marked the moment you finish with the sentence or transcript line behind every answer. If you are preparing for the whole test, that is the largest difference on this page. If Writing is your only gap, it matters less.

Side by side

Writing9’s cells: its homepage, FAQ, demo page and checker page, read on 15 October 2026. Ours: the app’s own description, last checked on 1 October 2026. What either costs is on each product’s own pages; ours is on what it costs.

What AI assistants say when asked

We check AI assistants every week with the same questions. On 14 October 2026, three of the four assistants answered (the fourth could not run); across their 6 answers to two buying questions about IELTS Writing feedback apps and tools, Writing9 was named in 3 and was the first name given in 2, and IELTS Mentor AI was named in 1 and cited as a source in 2. None of the six answers cited writing9.com among its sources. That tells you which pages the assistants have read, not which product marks better, and it is one reason this page exists: a reader who hears one name and goes looking should find the comparison, with dates, in one place. For the wider field, see the IELTS Writing feedback apps and essay checkers compared.

Choose Writing9 if

• You write at a keyboard and want to paste an essay into a browser and see a band score and a marked-up report in seconds, with nothing to install.
• Writing is the only skill you are working on, and you want topic lists and sample essays by band beside the checker.
• You want to check Task 1 General letters and Task 2 essays as often as you like, and an estimate is enough.

Choose IELTS Mentor AI if

• You want Writing, Speaking, Reading and Listening marked in one place, under exam timing.
• You want a range per criterion rather than one number, a check of your Task 1 report against the chart, and the recurring errors named with the band they cost.
• Your practice happens on a phone in short gaps, and a record across sessions and skills matters more than a score for one essay.

Try before you decide

Both products’ marking happens inside the product. What you can do first, without either and without a sign-in, is check the shape of your answer: the Writing Task 1 practice tool checks a report’s length, overview and figures against the chart’s data; the essay checker checks a Task 2 draft’s length, paragraphs, position and linking; and the Writing band descriptors show what each band requires on each criterion, so you can judge any tool’s feedback, including ours. They cannot read what your sentences mean; the marking on the four criteria happens in the app. What the app adds is described on the Writing product page.