1. Google Opinion Rewards

One of the easiest and most reliable ways to earn free Google Play credits is through Google Opinion Rewards. This official app from Google allows you to answer simple surveys in exchange for Google Play credits.
How it works:
Download the Google Opinion Rewards app from the Google Play Store.
Complete short surveys that typically ask for your opinion on various topics.
Earn Google Play credits after completing each survey, which you can redeem for apps, games, movies, and other digital content.
The amount of credit earned per survey varies, but it’s a great way to gradually build up funds for your next purchase on the Play Store. Keep in mind that the surveys are usually location-specific and may not be available all the time.
2.Reward Apps and Websites
There are several apps and websites that offer reward points for completing simple tasks, such as watching ads, testing apps, or taking surveys. These reward points can be converted into Google Play gift cards or redeem codes. Popular reward apps include:
Swagbucks: By watching videos, shopping online, or completing surveys, you can earn Swagbucks (SB). These can be redeemed for Google Play gift cards.
InboxDollars: This app rewards you for completing tasks like reading emails, playing games, or taking surveys. You can redeem your earnings for Google Play gift cards.
Mistplay: Available exclusively on Android, Mistplay rewards you for playing mobile games. The more you play, the more points you earn, which can be redeemed for Google Play gift cards.

3. Participating in Giveaways
Many websites, social media influencers, and blogs often host giveaways of Google Play gift cards or redeem codes. These giveaways are typically free to enter, and you can win codes through random draws or contests. Some common places to find such giveaways include:
Reddit: Subreddits like r/Android, r/Freebies, and r/GooglePlay often feature giveaways of Google Play gift cards. Be sure to check for legitimacy and avoid scams.
Social Media: Follow your favorite tech influencers, YouTubers, or app developers on platforms like Instagram, Twitter, and Facebook. Many offer free Google Play codes as part of their promotional activities.
Tech Blogs and Forums: Tech blogs sometimes offer promotional giveaways, including Google Play credits, as part of a partnership with app developers or advertisers.

4. Referral Programs
Some apps and services offer referral bonuses where you can earn credits by inviting friends to join.
When your referred friends sign up or make a purchase, you receive a reward that could be in the form of Google Play gift cards or redeem codes. Popular apps with referral programs include:
Cash App: When you refer a friend to Cash App, both you and your friend can earn a bonus, which can be converted into a Google Play gift card.
Rakuten (formerly Ebates): Rakuten offers cashback rewards for online shopping, and they sometimes offer the option to redeem those earnings for Google Play credits.
Make sure you’re aware of any referral bonuses or promotions being offered and share your unique code with friends to maximize your rewards.

5. Google Play Promotions and Offers
Google occasionally offers promotional discounts, especially around holidays or special events. They sometimes give away free codes or credits as part of a larger promotion. These promotions may include:
Free credits for new accounts: Google sometimes gives new users free credits for signing up to Google Play services.
Seasonal or holiday offers: Keep an eye out for holiday deals, like “Google Play Summer Sale” or “Black Friday deals,” where Google may offer free credits as part of limited-time promotions.
You can check for these offers on the official Google Play Store website or by subscribing to their newsletter to stay updated on any new deals.
