Browsing offers on Credit Karma does not affect your scores, but applying for a financial product (such as a loan or credit card) can.
If you see an offer you like and decide to apply, you can click through to the lender’s site to fill out an application. When you apply and the lender reviews your application, they’ll check your credit before making the lending decision. This typically causes a hard inquiry, which may lower your credit scores by a few points regardless of whether you are approved or declined.
The good news is that even though hard inquiries usually stay on your credit reports for about two years, their effects tend to wear off over time. Read more about hard and soft credit inquiries and why they matter.
Keep in mind that Credit Karma can't know for sure if lenders will approve or decline your application. However, you might see pre-approved offers and approval odds which may help you narrow down options when selecting your choices.