# Uncertainty score The API returns a confidence score of the cutout through the HTTP header `x-uncertainty-score`. The uncertainty score is a number between `0` and `1`: * `0` means the model is very confident that the cutout is accurate * `1` means the model is unsure. For instance, shoes on a shoe box might give a higher uncertainty score as the model is unsure what to segment (shoes, box or both):
High uncertainty score: between 0.6 and 1Low uncertainty score: between 0 and 0.3
{% hint style="warning" %} Please note that the uncertainty score is not guaranteed to be stable over time: the same image might yield a different uncertainty score in the future. {% endhint %} In some cases, we might not be able to able to return an uncertainty score (e.g. if an image contains humans), in that case the value `-1` will be returned.