I’m guessing they’re the type to put Al Qeada, ISIS, the Palestinian Islamic Jihad in the same category despite openly disagreeing with each other and being on different sides geopolitically.

Happy to clarify comrade. Islamism is not Islam. Islamism is a modernist political ideology and force whose roots are in the reaction of the Islamic world to Western Imperialism and Colonialism in the 19th century and the decline in political strength of the Islamic world. It's relative strength and influence in the contemporary world has to do not only with further radicalization

I would not say they are the same thing, as Fascism for me refers to strongly to a particular political phenomenon which is very much tied to the political and socio-economic history of Europe (or the capitalist-imperialist West). Aimé Cesaire's comment that it can be seen as the tools of imperialism turns inwards is relevant here, but I wouldn't use that to literally define fascism as it is too broad and captures more than the political phenomenon what the term 'fascism' was coined to capture.

The similarities in my mind are the following:

• They are both modernist ideologies that emerge in societies in socio-economic and political crisis. They serve a similar political function of crushing progressive forces, notably socialist political alternatives in the societies in question.
• Both present themselves as radical alternatives to secular, traditional conservative, liberal and socialist political forces, and which also offer a return to a mythical past through sacred bloodshed and violence.
• I don't particularly like the term 'totalitarian', as it tends to obscure more than it clarifies, but in this case I would say that the ambitions of Islamism are relatively totalizing in the reach and extremism of its ambitions. It generally would like to thoroughly reform all aspects of social life on a particular theocratic model.
• They are extremely socially reactionary, with emphasis on particular (in some ways modern/modernist) interpretations of tradition, and present themselves as revitalizing returns to the original, pure manifestation of a particular ideal form of society and political structure. In the European case the focus is on race The only case of European fascism I can think of which has been as ideologically theocratic would be the Romanian Iron Guard. This often manifests itself in violent death-cults with intense focuses and fetishizations of violence.
• They are both highly hierarchical and elitist. There is intense misogyny and hypermasculinity in both.
• Both were influenced in terms of their philosophies of revolutionary organization by the Bolshevik example. Shariati, for instance, one of the main ideologues in the history of Shia Islamism, was influenced not only by Islamic philosophy, but also explicitly by the clandestine methods of organization and agitation towards violent revolution as he thought evidenced by the Leninist model.

That being said there is also of course ideological and organizational variety among Islamist groups, just as there is among fascist groups. Groups like Hamas, Hezbollah and the Muslim Brotherhood base themselves on more open political competition, notably for mass-movement based electoral influence, while also operating with some independence outside of formal, liberally-condoned political options. So the similarities are more clear in terms of several super-structural aspects, but there is also the base-level similarity in that both emerge as reactionary radicalizing forces often aiming for mass radicalization and violent revolution as consequences and responses to the socio-economic and political crisis of their societies, in contexts of delegitimization of the established, liberal, secular, nationalist or socialist alternatives (for whatever reason, though in this case often very closely related to the fact that these societies are generally suffering intensely due to Western Imperialism, Colonialism and Neo-Colonialism.