Why Some Websites Don't Load on Jio or Airtel (and How to Check If Your Network Is Blocking Them)

A common, confusing experience: a website loads fine on your home WiFi, but the exact same site refuses to load on Jio or Airtel mobile data - or the reverse. Before assuming the site itself is down, it’s worth checking whether the cause is something happening at the network level: your ISP blocking or filtering the site.

The most familiar type: DNS-level blocking

Every time your device visits a website, it first asks a DNS server “what’s the IP address for this domain name?” Normally, that question gets answered and your browser connects directly. DNS-level blocking means the network’s DNS server is configured to give no answer (or a wrong one) for specific domains - so your device never even learns where to connect, and the site appears to simply not exist from that network’s point of view.

This is different from the website being down. The site can be running perfectly fine everywhere else; it’s specifically this network’s DNS resolution for that domain that’s been altered.

Why this happens on Indian ISPs

In India, telecom operators are sometimes legally directed - by courts or government authorities, under laws such as the Information Technology Act or in copyright infringement proceedings - to restrict access to specific websites. DNS filtering is only one of the ways it gets done. A March 2026 study of blocking across six major Indian ISPs (Jio, Airtel, ACT, MTNL, You Broadband and Connect Broadband, together roughly 82% of subscribers), reported by MediaNama, identified four techniques in use: HTTP-based blocking, DNS poisoning or injection, SNI-based TLS blocking, and IP/TCP-level blocking. Earlier research by the Centre for Internet and Society documented Jio inspecting the SNI field of HTTPS connections in 2019, which shows up to the user as an abrupt connection reset rather than any block notice.

The study also found the ISPs don’t apply identical block lists, and the report notes there is no official public list of blocked sites. That’s why the same site can load on one network and fail on another, or differ between mobile data and broadband/WiFi. This is a technical description of how blocking is observed to work, not a comment on which sites are affected or why.

How to check it yourself

You don’t need any special software - our DNS Lookup Tool does this in two steps:

Run a lookup on the domain. This queries a public, third-party DNS resolver (not your ISP’s), so it shows what the domain should resolve to, independent of any network-specific filtering.
Use the “Check Reachability From Your Network” button that appears below the results. This attempts an actual connection to the domain directly from your browser, over your current network - meaning it goes through your real ISP’s DNS and connection path.

If step 1 shows the domain resolves fine, but step 2 reports it’s not reachable from your network, that’s a real signal something is being filtered specifically on your current connection - not that the site is broken. The check can’t tell you which technique is responsible (DNS, SNI, or something else). Worth knowing: this isn’t a perfect diagnosis. An ad blocker, a browser extension, a corporate/home firewall, or a temporary network hiccup can produce the same mismatch, so treat it as a useful clue rather than a definitive verdict.

Other reasons a site might not load

Before concluding it’s network-level filtering, rule out the more mundane explanations:

The site itself might be down - check if it loads for you on a completely different network (like mobile data if you tested on WiFi, or vice versa) or ask someone on a different ISP.
A typo in the URL - easy to miss, especially on mobile keyboards.
Your device’s local DNS cache - occasionally holds onto an old, incorrect result; restarting your router or flushing DNS cache can rule this out.
The domain’s own DNS misconfiguration - sometimes a site’s own DNS records are broken, which our tool would also reveal by returning no records at all, on any resolver.

If you’re trying to understand your broader options

This post is about diagnosing why something isn’t loading, not about what to do next - that depends entirely on your own situation and judgment. If you’re generally curious about how proxies and VPNs relate to network-level restrictions and privacy more broadly, our Proxy vs VPN guide covers how each actually works.