The question of whether DNS over HTTPS (DoH) completely hides your browsing activity from your Internet Service Provider (ISP) is a complex one, with the answer being: partially, but not entirely.
Let's break down why.
The Domain Name System (DNS) is the phonebook of the internet. When you type a website address (like www.example.com) into your browser, your computer needs to translate that human-readable name into a numerical IP address that computers understand. This translation is done by DNS servers.
Traditionally, your computer would query your ISP's DNS servers to perform this lookup. This means your ISP sees every website you visit, even if you use HTTPS (which encrypts the content of your communication, but not the destination).
DoH encrypts the DNS lookups themselves, sending them over HTTPS to a DNS provider of your choice (like Google Public DNS, Cloudflare DNS, or others). This means your ISP can still see that you're communicating with a DNS server, but they can't see which websites you're trying to access.
The level of privacy DoH provides depends heavily on the context. In scenarios where an ISP is actively monitoring user activity (for example, in countries with strict internet censorship or where ISPs actively sell user data), DoH offers a significant improvement in privacy. However, it's crucial to understand that DoH is not a silver bullet.
For enhanced privacy, DoH can be used in conjunction with other tools like VPNs. A VPN encrypts your entire internet traffic, masking your IP address and hiding your activity from both your ISP and any third-party observers. This, in conjunction with DoH, would substantially increase your privacy.
DoH significantly improves your privacy by encrypting your DNS lookups, preventing your ISP from directly seeing which websites you visit. However, it doesn't offer complete anonymity. Your IP address and overall internet usage patterns remain visible. To achieve a higher degree of privacy, combining DoH with other privacy tools like a VPN is advisable.