If a website opens on one network in India and not another, or works on mobile but not on broadband, an ISP-level block is a likely reason. Blocks are applied under government orders or court orders (for example against piracy sites) and each provider carries them out in its own way. This guide explains the common mechanisms so you can tell what is happening and what a DNS change can and cannot do.
How websites get blocked
| Method | What happens | Does changing DNS help? |
|---|---|---|
| DNS blocking | The ISP's DNS server returns no answer, a wrong answer or a notice page for the site name. | Often yes: a different DNS service returns the real address. |
| SNI / HTTP filtering | The ISP inspects the site name in the unencrypted part of a connection and cuts it off. | No. The connection is blocked after DNS succeeds. |
| IP blocking | The address itself is blocked. | No. |
Which method is used differs by provider, and over time. Many ISPs use a combination, and mobile and broadband networks of the same company can behave differently.
How to tell whether it is DNS
- Run the DNS leak test to see which DNS servers your provider uses.
- Change your DNS to an encrypted public service and reload the site.
- If the site now loads, the block was DNS-level. If you still see a block page or a connection reset, the block is at the SNI or IP level.
Using encrypted DNS (DNS over HTTPS or Private DNS on Android) also protects against your ISP rewriting answers on the way. It does not hide the names you connect to from your ISP, because those still appear in unencrypted connection details unless the site supports newer standards such as Encrypted Client Hello.
What a VPN changes
A VPN hides both lookups and destinations from your ISP, so it can get around all three blocking methods. That does not make every use appropriate: a site may be blocked because a court found it infringing, and accessing unlawful content remains unlawful. Check what applies to you, and do not use any tool to access material you are not permitted to.
CGNAT and mobile networks
Many Indian mobile connections share addresses through CGNAT, which is also why the same site can behave differently on different networks and why IP geolocation can place you in another city. See what an IP address is.
Privacy trade-offs
Switching DNS or adding a VPN moves trust from your ISP to another company. Choose services with clear privacy policies, avoid free VPNs of unknown origin and test the result with our tools.