Yes, it is Haram (forbidden) to eat chicken blood for Muslims.
Islamically, the consumption of blood, regardless of its source, is strictly prohibited. The Quran explicitly forbids it:
"Forbidden to you (for food) are dead meat, blood, the flesh of swine, and that on which hath been invoked the name of other than Allah". Surah Al-Ma'ida (5:3).
This verse serves as a clear directive against consuming blood in any form. Therefore, any food containing chicken blood is considered non-Halal (not permissible). This prohibition extends to all types of blood, not just chicken blood.
While some cultures utilize blood as a food ingredient, this practice is not permissible within Islamic dietary guidelines. Muslims must ensure that the food they consume is free from any traces of blood to adhere to religious principles.