# How credits work

> What each kind of check costs, when credits roll over, and what happens if a scan fails.

Canonical page: https://winstonai.ai/help/how-credits-work

Help center: Billing & credits. Updated 2026-10-01.

Credits measure how much you scan. Each kind of check has a fixed cost, and we show the total before anything runs.

Credit cost by check

| Check | Cost | Example |
| --- | --- | --- |
| AI text detection | 1 credit per word | A 1,200-word essay uses 1,200 credits. |
| Plagiarism check | 2 credits per word | The same essay uses 2,400 credits. |
| AI image detection | 300 credits per image | A set of 10 images uses 3,000 credits. |
| Writing feedback and readability | 0 extra credits | Included with every text scan. |

## Monthly credits and rollover

Paid plans add credits every month on your billing date. Yearly plans receive credits monthly too, which keeps usage even across the year. Unused credits roll over for as long as your subscription is active.

## When credits come back

- **A scan fails or times out:** the credits return to your balance automatically.
- **You cancel a scan before it finishes:** the credits return to your balance.
- **You delete a finished scan:** credits aren't returned, because the check has already run.

## Running low

Your balance is on the **Billing** page of your dashboard. If you run out mid-month you can upgrade at any time, and the new plan's credits are available straight away. See [plans and prices](https://winstonai.ai/pricing).

> **Tip:** Free accounts get a one-time credit allowance that doesn't expire. It's enough to try the detector on several real pieces of writing.