7 WritingFirst, a disclosure: we make 7 Writing, an IELTS Writing course with AI feedback, so this article is not written by a neutral third party. We have not run our own head-to-head test of these tools, and we do not publish a ranking. What we did is simpler: we read several "best AI IELTS checker" lists and comparison posts, noted what they say and what they leave out, and turned that into five questions you can use to judge a tool yourself.
- Look at how it is writtenWho wrote it, and what the ranking is based on
- Find the common pointsWhat blogs say about AI scoring
- Ask five questionsChoose for yourself, not by ranking
- Run one self-test15 minutes, using essays a teacher has already marked
How other people write these comparisons
Search for "AI IELTS writing checker" and most of the top results follow one pattern: a list of tools, a short paragraph for each, and a pros-and-cons block. We picked three to read closely.
- The PREP blog post "10 free IELTS Writing checkers that are actually good" (originally in Vietnamese). It covers ten tools, each with a pros-and-cons list. PREP ranks second, and it is the publisher's own product. Its entry is the longest, yet its cons section has a single point: human marking costs money. The post does not explain how the ranking was made, and it ends with a sign-up button. Its section on ChatGPT is more candid: the tool was not built for IELTS, and its predicted scores are unstable and depend on the prompt.
- ECE English's "7 free IELTS Writing checkers" (originally in Vietnamese). It sorts tools into two groups: AI scoring and peer marking between learners. Each tool comes with a clear use case. ChatGPT, for example, suits brainstorming and basic grammar fixes, while Grammarly suits a final proofread. The text does not advertise the publisher's own courses; the consultation button and banners sit around the page. It also gives no ranking method, but it repeats several times that AI scores are for reference only.
- PrepEx's "Engnovate vs PrepEx". It opens by introducing PrepEx itself and lists the competitor's free allowance, though it says much less about the competitor. The most notable part is the ending: the post states that it was published by PrepEx, which is one of the products being compared. It also says plainly that the authors never ran a paid, side-by-side scoring test, so they cannot prove which tool marks more accurately.
Read together, the three posts show what to copy and what to avoid.
- Worth copying: say who is publishing; write the downsides plainly; admit when you have not tested something; describe which situation each tool suits.
- Not worth copying: rank without stating the basis; list only one downside for your own product.
What these posts agree on
The details differ, but several points come up again and again:
- AI is fairly reliable on surface errors such as grammar, vocabulary and sentence structure. It is weaker on Task Response and Coherence and Cohesion, because those criteria require understanding an argument.
- The score an AI gives is a reference, not the score you will get in the exam.
- Free tools help most while your foundations are still being built. From about Band 7.5 upward, you still need a person to look at your argument.
- Nobody has put these tools through the same set of essays and published the scores side by side. We could not find such a test either, so we do not know which tool is "the most accurate".
The last point deserves emphasis: if nobody has tested them, every ranking is just the author's preference.
Five questions to ask before you choose
- Which criteria does it mark against? Does it follow the four official criteria: Task Response, Coherence and Cohesion, Lexical Resource, and Grammatical Range and Accuracy?
- If you submit the same essay twice, do you get the same score? If the two scores differ by 0.5 or more, do not trust it too much.
- Does it only give a score, or does it point to the sentences with problems and show how to fix them?
- Does it say "AI can be wrong" and give a rough margin of error? The vaguer it is, the more careful you should be.
- After you revise, can you practise again and check your revision? A tool that marks once does little to help you improve.
To see how the four criteria differ when moving from Band 6 to 6.5, read How to move from Band 6 to 6.5 in IELTS Writing. For using linking words to make an argument clearer, see More linking words are not better.
A rough map of the tool types
The table below only uses information from public pages and the three posts above. Prices and allowances change, so check each provider's official page.
| Type | What it does well | Limits |
|---|---|---|
| Write & Improve (Cambridge) | Basic features are free, feedback is fast, good for checking grammar and word choice. It uses the European CEFR scale and does not give an IELTS band | Not designed around the four IELTS criteria |
| IELTS-specific tools, for example IELTS.international | Scores against the four criteria with a comment on each. There is a free allowance; paid plans are priced separately, see the official page | Accuracy figures mostly come from the provider, so test it yourself |
| ChatGPT and other general models | Free or already in your account; good for brainstorming, basic grammar fixes and follow-up questions | Scores change with the prompt; weak on Task Response and Coherence and Cohesion |
| Community peer marking (such as Essay Forum) | Free, and you get real people's comments on your view and argument | No one guarantees a reply; quality is uneven |
| A teacher marking directly | Understands what you mean and points out problems in the argument | Expensive, slow, and you have to queue |
How we do it, and what limits us
7 Writing puts AI feedback inside a course: study a section, write a short paragraph, get it marked, revise using the feedback, then return to a review queue. Specifically:
- Signing up gives you 3 free AI reviews. The course includes 60 reviews, with at most 3 per day. Detailed usage rules will be published after launch.
- A review shows which sentence has which problem and offers a model revision. On the page we say it plainly: AI can be wrong, the score is only for finding problems, and the margin of error is roughly 0.5 to 1 band. That figure is our own estimate, not a third-party assessment.
- The course content is compiled from materials by a Band 8 Writing teacher.
- We have not published any comparison, so we cannot say we are "more accurate than the others". What we can say is that each score comes with specific sentences and fixes, and you can check for yourself whether the comments are right.
Run one self-test
If you do not want to trust any ranking, you can run a small experiment in 15 minutes:
- Pick 3 IELTS Writing essays already marked by a teacher or examiner, including both Task 1 and Task 2.
- Submit each one to the tools you want to compare and record the overall score and each criterion's score.
- Submit the same essay again to see whether the score is stable.
- Compare with the teacher's score to see the gap, and check whether you can fix the essay straight away using the tool's suggestions.
The tool with the closest score is not necessarily the best for you. The tool that helps is the one that tells you how to fix the next sentence.
The first two chapters are free, so you can try the course now.
To try your own essay, paste a Task 2 into the free IELTS Writing checker: one free check, and 3 more free checks after you sign up. AI scores are for reference only.