Why does it only take 2 minutes to withdraw a WeChat message?

The ancients said, "Once words are spoken, they cannot be taken back," which shows how important it is to speak.

But people always say the wrong thing sometimes!

In order to solve the problem of "slipping hands", WeChat launched the "WeChat withdraw" function in version 5.3.1.16, providing a withdrawal option for messages sent within 2 minutes↓↓↓

The user long presses the sent message (including pictures) and chooses to withdraw in the multiple selection.

So here comes the question…

Why can sent messages be easily withdrawn?

In the Korean drama "My Love from the Star", in order to prevent Cheon Song Yi from seeing the "confession" text message sent subconsciously, our Professor Do did not hesitate to use the two "killer weapons" of time and space travel and space stillness.

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In fact, there is no need to envy Professor Do. Since the WeChat withdraw function was introduced, every WeChat user can have superpowers and withdraw messages easily.

So, without resorting to super powers, how does WeChat achieve the withdrawal of messages from both parties’ phones at the same time?

Take MobileA sending a message to MobileB and withdrawing the message as an example:

• A. When MobileA sends a message, it will generate a globally unique UniqueMsgID on its own WeChat client and attach the UniqueMsgID to the message body to be sent.
• B. When MobileB receives the message, it stores the message body and displays the message.
• C. When MobileA withdraws a message, MobileA knows the UniqueMsgID of each message body it has sent. If MobileA needs to withdraw a message, it will attach the UniqueMsgID of that message to the withdrawal command.
• D. When MobileB receives the withdrawal command, it searches for the corresponding message body in its own database according to the UniqueMsgID in the withdrawal command, and then displays the withdrawal effect.

Why can WeChat only recall messages within 2 minutes?

The mobile Internet era has forced everyone into an era of asynchronous information processing. Most people will wait a while before processing messages. In comparison, two minutes seems a bit too short. People often encounter the dilemma of wanting to withdraw a message only to find that the validity period has expired.

So, do we need to set a withdrawal deadline? The answer is undoubtedly yes.

In a two-way conversation, if you don’t set a withdrawal time, two hazards will occur:

• A. After a message is sent, if a withdrawal time is not set, for some messages that have been sent for a long time, it is very likely that the recipient has already seen them. If the sender withdraws the message, the relationship between the two parties will become more awkward, and even cause unnecessary misunderstandings.
• B. After the message is sent, if the withdrawal time is set, the sender can withdraw any historical message, which will result in incomplete conversation context and affect user experience.

So why is the withdrawal time 2 minutes? Can't it be more or less?

In this regard, the WeChat product team conducted a big data analysis and concluded that, from the perspective of the information recipient, 2 minutes is the average time it takes to read a message, and withdrawing the message within 2 minutes will keep the context intact to the greatest extent possible, providing a stable user experience.

If it is shorter than 2 minutes, the person who posted the information may not realize the error in the information and may have missed the opportunity to withdraw it.

If it is longer than 2 minutes, the probability of the message being read by the recipient will be greatly increased, and the sender will no longer need to withdraw the message. In addition, withdrawing a message sent a long time ago will destroy the context coherence and seriously affect the conversation experience and effect.

Instead of setting a time limit, why not remind the other party that the message has been read in the recall function?

Although 2 minutes is the average time from receiving to reading a message, we have no way of knowing when the recipient will actually read the message. This can cause the recall function to not be timely at times, leading to the famous "Schrödinger's cat" problem.

So, why doesn’t WeChat prompt the other party that the message has been read in the withdraw function? In this way, the sender of the message can choose whether to withdraw it according to the situation.

If there is a reading prompt function, the receiver will know that the sender already knows that he has seen the message that the other party wants to withdraw, which will make both parties more embarrassed.

More often than not, the receiver does not want the sender to know whether he or she has read the message. For example, in a common employee-boss group, after the boss sends a message, if he or she finds that the employee has read the message but did not reply (for example, he or she is on a date), then over time, the boss will inevitably become dissatisfied with the employee.

But if there is no prompt for read or unread messages, the boss will not know whether the employees are online, and the employees will not have to keep an eye on their phones all the time.

The product philosophy behind these settings is that WeChat does not want to put pressure on the recipient of the message. Compared with the sender and the receiver, WeChat pays more attention to the receiver's experience.

Why does WeChat show a text prompt when withdrawing a message?

Since withdrawing a message provides users with a kind of regret medicine, why should they leave a reminder "label" saying "someone withdrew a message" after taking it?

The WeChat message withdrawal is a bit like the email withdrawal. At the moment of sending, the other party has actually been "notified" on the lock screen, so it is difficult to leave no trace.

Taking Apple mobile phones as an example, as long as the "Notification Display Details" of WeChat is turned on and the phone is allowed to display WeChat "Notifications", even if the other party withdraws the message, it can be found on the "Notification" of the Apple mobile phone:

Since everyone is not Professor Do with special abilities, the information release conference will definitely leave traces. If the recipient receives the notification but finds that there is no message after opening it, he or she will think that the message is lost and ask the sender to resend it, which will make both parties more embarrassed.

In addition, in some specific situations such as business negotiations or loans, if there is no text prompt when withdrawing information, it will cause damage to the other party's interests.

For example, the borrowing problem mentioned by Zhihu netizens:

From the perspective of function development, the creation of the withdraw function is designed to take into account normal usage scenarios such as typos or sending to the wrong person.

For those special scenarios (such as lovers quarreling, etc.), users should try to control their emotions and avoid "acting impulsively" before sending messages, so as not to miss the withdrawal time and unfortunately cause a "tragedy".