Why Is WhatsApp Not Sending Messages? The Fix for Every Version of This Problem

The short version: the most common cause is a weak or interrupted internet connection, followed by the recipient having blocked you, followed by a temporary WhatsApp server issue. A message stuck on one grey tick with a clock icon means it left your phone but has not reached WhatsApp's servers yet, almost always a connection problem on your end rather than theirs.

Work out which symptom you have first

"Not sending" covers several different problems and each has a different cause, so start by identifying exactly what you see next to the message:

• A clock icon only: the message has not left your phone at all, usually no internet connection.
• One grey tick: the message left your phone and reached WhatsApp's server but has not been delivered to the recipient's phone.
• Two grey ticks: delivered to the recipient's device, but not yet read.
• Two blue ticks: read.
• Two grey ticks that never turn blue, for a long time, on one specific contact only: often means the recipient has turned off read receipts, not a problem with sending.
• A red exclamation mark with "not sent" text: the message failed outright and needs to be resent manually.

The most likely cause: your own internet connection

WhatsApp needs a stable connection to send anything past the clock icon stage. A weak mobile signal, a wifi network that is connected but not passing data (common on public wifi that needs a login page), or being in airplane mode without knowing it, are the usual culprits. Test this quickly by trying to load a webpage or refresh another app that needs the internet. If nothing else loads either, this is your answer.

The second most likely cause: you have been blocked

If messages to one specific person consistently sit on one grey tick and never move to two, their profile picture has disappeared, their last seen and online status no longer show, and you cannot see updates to their status, you have very likely been blocked by that contact. This only affects messages to that one person and every other chat sends normally, which is the clearest way to tell it apart from a connection issue.

Check your connection on iPhone

• Swipe down from the top right to open Control Centre and check the wifi and mobile signal icons are active, not showing airplane mode.
• Go to Settings, then WhatsApp, and check Cellular Data is switched on if you are not on wifi.
• Try turning wifi off completely for thirty seconds to force a switch to mobile data, then try sending again.
• If on wifi, forget the network in Settings, then Wi-Fi, then reconnect and re-enter the password.

Check your connection on Android

• Pull down the notification shade and confirm wifi or mobile data is on and airplane mode is off.
• Go to Settings, then Apps, then WhatsApp, then Mobile data and Wi-Fi, and confirm background data is allowed.
• Try toggling airplane mode on for ten seconds then off again, which forces the phone to reconnect to the network fresh.
• Check Settings, then Battery, then Battery optimisation, and confirm WhatsApp is not restricted, since some Android phones aggressively limit background data for apps to save power, which blocks message sending even with a good connection.

Check whether it is WhatsApp Web or Desktop specifically

WhatsApp Web and the desktop app both rely on your phone staying connected to the internet, since they mirror your phone's connection rather than working independently in most setups. If messages send fine on your phone but not on the linked desktop version, check that your phone itself has an active connection and that the desktop app shows as linked under Settings, then Linked Devices, on your phone. If the phone was offline for a long period, the linked session can drop and needs re-linking by scanning the QR code again.

Check for a wider WhatsApp outage

WhatsApp does have occasional outages affecting a large number of users at once, usually lasting from a few minutes to a few hours. If sending is failing across every single chat, not just one contact, and other people you know are reporting the same thing, this is more likely a server issue on WhatsApp's side than anything on your phone. There is nothing to fix on your end in this case except to wait, since retrying repeatedly does not speed anything up and can queue up duplicate failed messages.

A quick way to confirm an outage rather than guess is to check whether other apps that rely on similar messaging infrastructure are also behaving oddly at the same time, and to ask a contact on a completely different mobile network whether they see the same failure. If the pattern is widespread across networks and devices at once, it points firmly away from anything on your specific phone.

Steps that fix most non-outage cases

1. Restart the phone completely, not just the app, since this clears background processes that quietly block network access.
2. Check the date and time on the phone are set to automatic, since WhatsApp uses this to verify the connection and an incorrect clock can block sending entirely.
3. Clear WhatsApp's cache (Android: Settings, Apps, WhatsApp, Storage, Clear cache; this does not delete your messages, only temporary files).
4. Update the app to the current version from your phone's app store, since an outdated version occasionally loses server compatibility.
5. Check available storage space on the phone. Extremely low storage (under a few hundred megabytes free) can cause apps to fail at basic tasks including sending messages.

Check if the recipient has WhatsApp installed and active

If a contact has deleted WhatsApp, switched phone numbers without updating their account, or has not opened the app in a long time, messages can sit on one grey tick indefinitely, since there is no active device to deliver to. This looks identical to a connection problem on your end at first glance, so it is worth confirming through another channel, such as a text message or a call, whether that person still has WhatsApp active on their current number.

What does not work: the myths worth dropping

Deleting and reinstalling WhatsApp does not fix a connection or blocking issue and risks losing chat history if it is not backed up first. Turning the phone to airplane mode and back rarely helps beyond forcing a basic reconnect, and doing it repeatedly does nothing extra. Changing your WhatsApp profile photo or status to "test" whether someone has blocked you does not give a reliable answer, since a blocked contact will simply not see the change, which looks identical to several other explanations. And a VPN does not fix message sending in almost all cases, and can occasionally make it worse by routing your connection through a slower or blocked server region.

When to contact WhatsApp support

Contact WhatsApp directly (Settings, then Help, then Contact us, inside the app) if: sending fails across every chat despite a confirmed working internet connection on other apps, your account shows as banned or restricted when opening the app, you suspect your account has been compromised, or the problem persists for more than 24 hours with no wider outage reported. For a single contact issue that looks like blocking, support cannot confirm or deny a block either way, since WhatsApp does not disclose that information to protect user privacy.

I have written more around this on the site: Why Is WhatsApp Showing One Tick Only on Your Messages, How Do You Design WhatsApp Business Templates That Convert, How the WhatsApp Business API Works for Growing Companies.

I keep every related walkthrough in the WhatsApp Help: 43 Guides to Transfers, Backups, Business and Privacy.

Related: how to transfer WhatsApp messages to a new phone without a backup.

Related: no code (this site).

Related reading: mobile carrier or wifi network does not support whatsapp calls.

Frequently asked questions

How can I tell the difference between being blocked and a connection problem?

A connection problem affects every chat equally and usually resolves once you fix your wifi or mobile data. Being blocked only affects messages to one specific contact, while every other chat sends and delivers normally in the same moment, which is the clearest single test.

Why does my message show one grey tick for hours then suddenly deliver?

This usually means the recipient's phone was offline, switched off, or in a very poor signal area. WhatsApp holds the message on its servers and delivers it the moment the recipient's device reconnects, which can be anywhere from minutes to a day or two later depending on how long they were offline.

Does WhatsApp Web stop working if my phone battery dies?

On most current WhatsApp setups, linked devices including Web and Desktop can continue working for a period even if the phone is offline, but a phone that has been off for an extended period, generally more than about two weeks, will cause linked devices to disconnect and need re-linking with a fresh QR code scan.

Can low storage on my phone really stop messages from sending?

Yes. When a phone has very little free storage left, background processes including network requests can fail or be throttled by the operating system, and WhatsApp specifically can fail to send media or even text messages until enough space is freed up.

Why do messages send fine on wifi but fail on mobile data, or the other way round?

This points to a specific network rather than WhatsApp itself. A mobile data plan with a data cap reached, a wifi network with a login page that has not been completed, or a work or public wifi network that blocks certain app traffic, can each cause sending to fail on one connection type while working fine on the other.

Sources worth reading

• WhatsApp's own Help Centre