Can I repay credit card fast to improve score to buy a house?

It is always better to repay your credit score. It will help to improve your credit score when you repay the balances in full. However, it won't happen overnight., You will have to wait for a few months, usually about 3-4 months to get it reflected in your credit scores.
Try to add positive items in your credit report and dispute inaccurate items, if any. This will also help to improve your score.

Repaying the credit card bill is always good. But it will not increase the score fast. To increase the credit score, you need to manage the cards properly along with other monthly bills. Pay all your bills on time. Also stay within your credit report. This will help you to add positive listings on your report. After a some time, you can see a positive changes in your credit score.

You have to wait till the next billing cycle. Okay. Paying off credit cards can help you improve credit score when your credit utilization ratio drops significantly. Don't close the accounts after paying off credit cards since that would hurt your payment history and lower credit score.

It is always better to repay your credit card debts in full. Not only it'll help improve your credit score and add positive information in your credit report, but also it'll prove yourself to be creditworthy to your future creditors.