Your phone and carrier both need to support RCS messaging though, and you have to have it enabled if you want the reactions to work. Otherwise there's no option to use them.
For those who do not know, reactions allow you to respond to a message using one of seven reactions. To clarify the reactions are thumbs-up, thumbs-down, heart eyes, laughing with tears, surprised, sad, or angry. Now with the rollout of these reactions to their web client Google is giving users more options.
Google Messages Reactions On The Web
Google’s Messages web client allows users to send messages from their laptop via their browser. This is useful for those times when you do not or can not have your phone out, but you need to stay in contact with someone. Now using these reactions on the web is super easy. Firstly, you hover next to any message to reveal new icons. The first icon is an emoji and the second one is an overflow options button.
Secondly, all you must do is click on the emoji and then you get the option of the seven reactions mentioned earlier. If someone sends a message that you absolutely love you can use the heart eyes reaction. If someone sends a message that hits a certain nerve you can use the angry reaction. These reactions help to convey more of an accurate emotional response to something someone may say.
However, you can only give one reaction to a message. This doesn’t make your choice permanent which is a good thing. So, if you accidentally click the angry reaction when you meant to choose the heart eyes reaction, you can override your first choice. Firstly, repeat the steps to bring up the reaction choices. Secondly, choose a new reaction. After that, the new reaction you choose will override your first option. Therefore, if you choose the second option quick enough you may be able to avoid an awkward situation.
Google continues to improve its Messages app in an attempt to give Android users a viable iMessage alternative. With the introduction of reactions in the app and now on the web users have more ways to express themselves. These reactions can be used in one-on-one conversations, or in group conversations. If you do not see the option to give a reaction on the web just yet it is okay. Google will roll out this feature to more users as time goes on. It was verified that for several accounts across several countries this was available.