For my home mortgage, If I get a bonus from work like $5000 and pay that to principal, will it lower the time or my monthly payment?

Let say I buy a house using home mortage and it is 30 years fixed. After 2 years, I get a big bonus from work (say $5000). If I pay that towards the principal of total loan (on top of monthly payments). Will that lower time frame (from 30 years to say 29.5 years) OR will it lower my monthly payment? thanks
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