The 23-year old's family said he had come to the UK with hopes for the future, and they will miss him dearly.
In a statement Mr Alhajali's family said: "Mohammad was a very amazing and kind person. He gave love to everyone. He came to the UK because he had ambitions and aims for his life and for his family.
"Our whole family will miss Mohammad dearly and he will never be forgotten.
"To God we belong and to him we return."
Mr Alhajali's older brother Omar - who was with him in the flat - survived the fire after they were separated on the way out.
Almost 65,000 people have signed a petition to bring his parents to the UK so they can attend Mr Alhajali's funeral.
The petition was set up by family friend Mirna Suleiman, 26, who had been ringing around numerous hospitals, rest centres and the casualty helpline for news of his fate before discovering that he had not made it out alive.
She chose to launch the campaign because, because as someone with Syrian family herself, she knew how difficult it was to obtain a visa for visits.
"I've tried to apply for a visa for my nan in Syria - appealed and appealed and got no response," she said.
The percentage of rejected visa applications for visits from Syria has soared after the country's devastating civil war began in 2011.
However, the Home Office has indicated that it will allow Mr Alhajali's family to come to the UK on compassionate grounds.
The Change.org petition follows a crowdfunding effort to pay for Mr Alhajali's funeral.