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We analyze the five main reasons for slow message sending#

March 14, 2025

Slow message sending

You've probably encountered a situation where a message sent to WhatsApp took a long time to reach the recipient. Slow sending of messages can be especially painful when you need to quickly convey important information. In this article, we'll look at five main reasons for this problem and give recommendations on how to fix them.

  1. Too much delay between sending messages
  2. Slow file upload
  3. Sending large files
  4. Mass mailing
  5. Messages with website links
  6. Conclusion

1. Too much delay between sending messages#

Sometimes the problem is in your account settings. The delaySendMessagesMilliseconds parameter determines the interval at which messages from the queue are sent. You can check the current value by calling the GetSettings method.

How it works#

The larger the interval, the longer the delay between sending messages. If the value is set to a large interval, messages will be sent slowly.

Solution#

The solution is to reduce the delay. Call the SetSettings method and specify the desired value in the delaySendMessagesMilliseconds parameters. The minimum interval is 500 ms.

Important! When reducing the interval, remember about security. Sending messages too quickly, especially when sending in bulk, can be perceived by WhatsApp as suspicious activity and lead to blocking the account. Therefore, be careful and do not set too small values. Read about how not to get banned in WhatsApp in our article.

2. Slow file upload#

If you send files via the SendFileByUrl method, the sending speed directly depends on the download speed of the file from your storage.

How it works#

If the server hosting the file is slow or overloaded, this will cause delays in downloading, and therefore in sending the message.

Solution#

  • Use a storage with a high download speed
  • Optimize the file size (reduce image resolution, compress video)
  • Consider using a different method of sending files (for example, uploading the file directly to the WhatsApp server)

3. Sending large files#

It is important to consider the size of the file you are sending. Large files (over 20 MB) take longer to download and send due to their large amount of data.

How it works#

Regardless of your network speed, preparing and sending a large file may take additional time.

Solution#

  • Reduce the size of files you send when possible
  • Use compression to reduce the size of media files
  • If sending a large file is necessary, warn the recipient of a possible delay

4. Mass mailing#

When sending mass mailings, WhatsApp automatically reduces the sending speed to avoid suspicions of sending spam.

How it works#

WhatsApp can set a delay of up to 30 seconds for each message when sending mass mailings. In addition, the presence of links, photos or other media files in messages increases the amount of data, which slows down the process even more.

Solution#

  • Plan your mailings in advance and take into account possible delays
  • Optimize the content of messages (reduce the size of media files, avoid using a lot of links)

5. Messages with website links#

Messages containing links to websites may be sent with a delay of up to 10 seconds.

How it works#

Messenger automatically creates previews for web links. The system needs time to receive data from the website (including the image) and generate the preview.

Solution#

  • If possible, avoid using links in messages that require quick sending
  • Use shortened links (e.g. via URL shortening services) to reduce the amount of data required to generate a preview

5. Conclusion#

Slow sending of messages in WhatsApp can be caused by various reasons – from account settings to the size of the files being sent. Knowing these reasons and following the suggested solutions, you can significantly speed up the process and make your communication in WhatsApp more efficient.

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