Prophet Muhammad (peace be upon him) never forced anyone to convert.
There are multiple verses of the Holy Quran condemning any use of force in matters of faith.
Critics claim that the concept of ‘Jizya’ was used to coerce non-Muslims into accepting Islam or face death.
Jizya was merely a form of tax, quite like the taxes we pay in Australia, and every other country in the world – irrespective of what religion we belong to.
In Ch.2 V.218 of the Holy Quran the concept of Jizya is also further explained. Jizya was the tax that non-Muslims had to pay as free subjects of the Muslim State in return for their protection and for being looked after as members of the state (just like our governments look after us using the tax we pay to them). Since the Holy Qur’an instructs that the jizya be voluntarily given, early Muslim rulers specifically forbade punishment on non-payment. Furthermore, only working men paid this tax. Women and children, the elderly, the unemployed, and the sick or disabled were all exempt.
It should be noted that while non-Muslims paid Jizya, Muslims paid a higher tax called the Zakat.
If we compare Muslims living in Madinah vs those that were not Muslims, we’d know that Muslims had to perform military duties to protect the State (including non-Muslims living there) from outside attacks, which the non-Muslims were exempt from.