Here are a few methods I always use to get online free gift cards.
Taking surveys is one method I have used to get gift cards without paying a dime. It might be time consuming, about 10-20 minutes; it is definitely worth the hustle. There are several websites that offer surveys in exchange of free gift cards, for instance, Swagbucks.
Watching videos online is also a great way of earning online gift cards. The best part is that I can have them playing in one tab of my browser while I am doing other things online.
Some companies like Swagbucks allow you to earn free gift cards when you use their search engines. To maximize the earnings from this method, I usually set it as my default search engine.
If like online shopping, then you are in for a great thing. You get points which can be redeemed to gift cards when you shop anything at online stores like Drop, Amazon, Groupon, and many more.
Many companies, Swagbucks for instance, pay users for referrals. You can use social media accounts to share the referral link, hence more earnings.