Messages sit on a single grey tick. A voice call rings, connects, and dies after four seconds. Photos stall at 0% forever. And the strangest part: it all works perfectly at home on Wi-Fi and falls apart the moment you step outside on mobile data — or exactly the other way round.

That Wi-Fi-versus-mobile-data split is the most useful clue you have, because the two networks fail for completely different reasons and need completely different fixes. This guide walks through both sides, plus the separate question of why calls break while text messages still go through, what to do on a laptop, and where a VPN genuinely helps and where it does not.

Why is WhatsApp not working?

Run this two-minute triage first. It tells you which half of the article you actually need:

  1. Turn Wi-Fi off, use mobile data only. Send a message and try a call.
  2. Turn mobile data off, use Wi-Fi only. Do the same two tests.
  3. Note whether text works but calls fail. That specific pattern has its own cause, covered below.
  4. Try a second device or ask someone in the same chat. If it works for them on the same network, the problem is your device.

Whatever the outcome, your chats, contacts and media are safe. Everything described here is about the connection between your phone and WhatsApp's servers, not about your data.

WhatsApp not working on mobile data: the settings that cause it

When Wi-Fi is fine and mobile data is not, the cause is nearly always a data-saving or battery setting on the phone rather than your carrier.

On iPhone and iPad:

  • Settings → Cellular → scroll down to WhatsApp → make sure its toggle is on. If it is off, the app works only on Wi-Fi.
  • Settings → Cellular → Cellular Data Options → turn Low Data Mode off.
  • Settings → General → Background App Refresh → WhatsApp on, or messages only arrive when you open the app.
  • Check Focus modes and Do Not Disturb, which can silence calls so completely that they look like they never arrived.

On Android:

  • Settings → Apps → WhatsApp → Mobile data & Wi-Fi → turn on both Background data and Unrestricted data usage.
  • Settings → Network & internet → Data Saver → add WhatsApp to the unrestricted list.
  • Settings → Apps → WhatsApp → Battery → Unrestricted. Aggressive battery management on some phone brands is a notorious cause of delayed messages.
  • In the app: Settings → Storage and data → Media auto-download → allow photos on mobile data if media never arrives.

One more carrier-side check: if your plan's data allowance is exhausted, many carriers keep basic browsing alive but throttle everything else to unusable speeds. Messages that send in the evening and fail at the end of the month tell that story.

WhatsApp not working on Wi-Fi: routers, hotels and office networks

The opposite pattern — fine on mobile data, broken on Wi-Fi — points at the network you are joined to.

Start simple: power-cycle the router for a full thirty seconds, and set DNS to 1.1.1.1 or 8.8.8.8 on the router or device. Then check whether you are on a captive portal network — hotels, airports, cafés and trains show a terms page that has to be accepted before anything else works, and a phone that reconnects automatically often skips it silently.

The deeper cause on guest and corporate networks is port policy. Chats travel over the same standard secure web port as any website, so they usually get through anywhere. Calls need a different kind of traffic that many restricted networks simply do not forward. That is why your messages send perfectly on hotel Wi-Fi while every call fails instantly — it is not your phone, and reinstalling will not change it.

Wi-Fi vs mobile data: which side is actually broken?

What happens Where the fault is What to do first
Works on Wi-Fi, fails on mobile data Phone data-saving or battery settings Allow background and unrestricted data
Works on mobile data, fails on Wi-Fi Router, DNS or network policy Reboot router, change DNS, check portal
Fails on both, works for others Your device or app install Clear cache, update, check date and time
Fails for everyone you know at once Service-side outage Wait; nothing local will help
Messages fine, calls always drop Real-time traffic blocked or too slow Enable "Use less data for calls"; change network
Media stuck at 0% Auto-download rules or a weak path Check media auto-download settings

If nothing above matches, check one boring setting that breaks WhatsApp in a way nobody expects: Settings → General → Date & Time → Set Automatically on iPhone, or the equivalent on Android. A clock that is wrong by several minutes causes the secure connection to fail outright.

Why do WhatsApp calls fail when messages still send?

Text is tiny and tolerant. A message can wait a second, arrive late and still be a perfect message. A voice or video call is a continuous real-time stream where a delay of a fraction of a second is audible and a two-second gap ends the call. So calls fail first on any connection that is congested, high-latency or restrictive, while chats keep flowing.

Three things help in practice:

  • In the app, turn on Settings → Storage and data → Use less data for calls. It lowers the bandwidth a call needs and rescues calls on weak connections.
  • Prefer 5 GHz Wi-Fi close to the router, or step outside for a better mobile signal. Call quality tracks signal quality far more tightly than messaging does.
  • On a hotel or office network, expect calls to be the thing that does not work, and plan around it.

WhatsApp not working on laptop or WhatsApp Web

The desktop app and web version are separate clients linked to your account, and they have their own failure list. Log out and relink the device from your phone (Settings → Linked devices) if it has gone stale — linked devices stop working after about two weeks in which your phone never comes online at all. Clear site data for web.whatsapp.com if the browser version shows a permanent loading screen, and test in an incognito window to rule out extensions. On a work laptop, remember that the same network policy that blocks calls on the phone applies here too.

How to choose a VPN for messaging

A VPN is relevant to WhatsApp in two specific situations. The first is public Wi-Fi: in hotels, airports and cafés, the network operator can see a great deal about what your device is doing, and an encrypted tunnel closes that. The second is a poor or congested route, which is the scenario where calls drop even though your signal bars look healthy — a tunnel to a well-connected nearby server gives the traffic a more predictable path.

Be equally clear about where it does not help. A VPN cannot fix an exhausted data allowance, a weak mobile signal, a broken router, or a platform-wide outage. It adds encryption and a chosen route, nothing more.

What matters when choosing one for messaging and calls:

  • Low latency and nearby servers — calls are latency-sensitive above all else.
  • Stable uptime, because a tunnel that drops takes your call with it.
  • A no-logs policy — private messaging through a provider that logs your traffic is a contradiction.
  • All platforms from one subscription, so the phone and the laptop behave the same way.

Orris VPN is built around those: VLESS, up to 1 Gbit/s, unlimited traffic, no logs, iOS, Android, Windows, macOS and Linux from one subscription, from ~$1.7/mo with a free trial, paid by card or crypto.

Related reading: how to set up a VPN on your router so every device at home is covered, why Instagram is not working, and which services do not connect in mainland China if you are travelling there.

FAQ

Why is WhatsApp not working on mobile data but fine on Wi-Fi? Almost always a phone setting: cellular permission off for the app, Low Data Mode on, Data Saver restricting background data, or battery optimisation suspending it.

Why is WhatsApp not working on Wi-Fi but fine on mobile data? The network you are joined to. Check for an unaccepted portal page, reboot the router, change DNS, and expect guest networks to restrict calls specifically.

Why do my WhatsApp messages have only one tick? One tick means it left your phone but has not reached the recipient's. That is either your outgoing path or their device being offline.

Why do WhatsApp calls keep dropping when texting works fine? Calls are real-time and need consistent low latency; text does not. Turn on "Use less data for calls" and test on a different network.

Does WhatsApp Web need my phone to be online? Not for everyday use, but the link expires if your phone stays offline for roughly two weeks. Relink from Settings → Linked devices.

Will reinstalling WhatsApp delete my chats? It can, if you have no recent backup. Back up first (Settings → Chats → Chat backup), and remember you also need your phone number to receive the verification code.

Why does WhatsApp stop delivering messages in the background on Android? Battery optimisation. Set the app to Unrestricted under Settings → Apps → WhatsApp → Battery.

Does WhatsApp work in mainland China? It does not connect on an ordinary local connection there. That is long-standing and well documented, so prepare before you travel rather than after you land.

Conclusion

The fastest route to a fix is the Wi-Fi-versus-mobile-data test. If mobile data is the broken side, the answer is in your phone's data and battery settings. If Wi-Fi is the broken side, it is the router, the portal page or the network's policy — and on guest networks, calls specifically are the thing that tends not to work. If both sides fail, check the clock, the app version and whether everyone else is having the same day.

Once you know which side is at fault, the fix usually takes a minute. And for the cases that are genuinely about the path — public Wi-Fi you do not control, or calls that drop on a congested route — a fast, no-logs VPN such as Orris gives you an encrypted tunnel and a predictable route on every device you carry.