It’s totally up to you. You can use as many as you want. Though Twitter has 280 characters limit, up to that there is no barrier for using Hashtags. While other platform of Social Medias does not restrict user from posting as many words as they want. So, let’s talk here what is the most appropriate number of hashtag one can use. Like mentioned earlier, Twitter restrict its user by limiting the number of character one can post at one time. So, you should think, do small research, and choose the most appropriate and relevant topic for adding hashtag on your post.

Hashtags Use on Twitter
The research carried by the Twitter itself has said that using the most appropriate hashtag can increase the attention of your post by up to 100 percent. But it should be kept on mind that using more hashtag would just do the reverse action. You have to do many retweets and doubling the engagement was a very big deal earlier. Now putting pound sign before your topic can do the miraculous thing. You need not to use it more only two (on Twitter) hashtags can do the job of more than 20 retweets.
What we can conclude from this fact that using two (max.) hashtags on Twitter is most appropriate, so that your post perform better. This article helps you to find your answer about how many hashtags use on social media like Facebook, YouTube, Twitter, Instagram, TikTok etc.
How Many Hashtags Use on Facebook
The case is different on Facebook. You can use as many hashtags as you want. But few studies have shown that using hashtag on Facebook does not boost your post attention as it on Twitter. It is obvious that it will direct you to the large conversation room but will not actually extend the reach of your posts. So, we will recommend you to add as many as you want but to avoid looking spam our recommendation will be always using less. Because too many hashtags on posts sometimes look filthy and deviate the focus of other user from your post. They would rather think the post is fake and has different interest. So, keeping simple and most relevant and few hashtags would do well on Facebook although it has been found that post without hashtag did fair well.
So the conclusion is Hashtag on Facebook has no/less effect on boosting your post and it’s up to you whether to add some on your post or not. The only point is it will take your post into larger conversation room and people with similar interest can reach it.
How Much Hashtags You Should Use on Instagram
On Instagram, hashtag usually puts an effective effort on boosting your post and making it available for the larger audience. Like on Facebook there is no saturation point up to how many numbers you can use hashtag. But a report has clearly said that the interactions on Twitter will be at peak when you use at least 11+ hashtags. Same rule follows it on Instagram too. Using too many hashtags is no good, rather it would leave your post looking malicious and spam.
Unlike Facebook and Twitter, on Instagram adding hashtag on comment section would do better than putting it on caption to tag your photos and videos. Comment section is not visible on Instagram unless you the click to see entire. So, the visible captions with more hashtags, can look spam leaving bad impression on user. Instead, if you add hashtags on comment section rather than putting them on caption you will get more comments on one hand and you can avoid spam looking post on other.
How to Use Hashtags on TikTok
Today, 1 billion active users on TikTok. Many peoples share same content/video but if you add hashtags on TikTok while uploading a video then you will get more likes, comments. Your video will be visible to maximum number of users. We have already discussed on how to use hashtags please have a look.