The diagnostic
The diagnostic is the first measurement. Until you have taken it, the plan on Today is a sensible default rather than yours, and Progress has nothing to draw.
What it consists of
Two attempts, chained, in one sitting:
| Part | What | Time |
|---|---|---|
| 1 | The easiest available reading passage | 20 min |
| 2 | A Task 2 essay | 40 min |
| Total | 60 min |
You are asked for a target band and a test date first, if you have not already given them.
The two halves are recorded as linked attempts, which is why the result page can show them as one sitting and one overall band while Progress still counts them as a reading attempt and a writing attempt.
Your result
Reading is marked the moment you submit it. Writing goes off to be marked, which takes up to a minute, so the result page may show your reading band first and fill in the essay when it lands. You can close the tab; the marking finishes without you.
The overall figure is the mean of the two. From it, Bandzen builds your study plan — and the plan is where the diagnostic actually pays off, because it now knows which of your two skills is behind and by how much.
Taking it more than once
Pro
Free includes 1 diagnostic. Retaking is a Pro feature. If you have already been measured, the page says so rather than letting you start one and stopping you at the end.
Retaking is not usually the useful move anyway. A second diagnostic measures the same two skills the same way; ordinary practice attempts feed Progress and the plan just as well, and Reading practice is unlimited on every plan.