The hashtag limits for the most popular social media platforms are as follows:

1- Twitter: Tweets can include up to 280 characters, and the hashtag limit per tweet is 140 characters. However, it's recommended to use only 1-2 relevant hashtags per tweet for better engagement and readability.

2- Instagram: Instagram allows up to 30 hashtags per post. While it's possible to include 30 hashtags, many users prefer to use between 5-10 hashtags to avoid appearing overly promotional.

3-Facebook: There is no official limit to the number of hashtags in a Facebook post, but it's advisable to use 1-2 relevant hashtags to avoid coming across as spammy.

4- LinkedIn: LinkedIn allows up to 30 hashtags per post, but similar to Instagram, using a more limited number of relevant hashtags (around 5-10) is often more effective.

5-Pinterest: For Pinterest, there's a limit of 20 hashtags per pin. It's generally recommended to use 2-5 relevant and specific hashtags per pin to improve discoverability.

It's important to note that while these are the current limits, best practices for using hashtags on social media often focus more on relevance, specificity, and moderation rather than hitting the maximum allowable number of hashtags.