While it's essential to be cautious when searching for free license keys online, AdGuard occasionally offers promotions and discounts. The best way to ensure you're getting a legitimate license is to:

Sites like StackSocial frequently offer "Lifetime Licenses" for AdGuard (for up to 3 or 9 devices) for as low as $15–$20. This is much cheaper than the monthly subscription.

The free version of AdGuard is mostly limited to browser filtering. The version is where the real power lies: