Is it bad to use a lot of Custom Meta Fields?

I am curious without doing a ton of benchmarks, how others feel about using several custom meta fields on a blog post? I am talking strictly performance wise, does it slow things down a lot if using a lot of fields, should we try to keep them to a minimum?

Currently for a regular blog post, I have a custom meta field for…

• Title: Used for page title
• Description: Used for meta description and social share description/text for Facebook and Twitter shares
• Keywords: Used for meta keywords

So I have 3 extra meta fields which are used so every article will have relevant SEO meta, also for when a user shares the article on Social networks, I can set the title and description easily.

I am wanting to add another field for Twitter #hashtags which I can then insert on Twitter shares, these will be similar to my articles tag taxonomy but may differ some so that is why I am thinking a custom meta field is the way to go.

I am also in the process of doing a custom post type for a portfolio which would also in addition to the above custom meta would add several more meta fields for this post type.

That is why I am curious about the performance impact of adding several meta fields?

Please share your thoughts

Custom Fields are normally fetched in a single query to the database, so fetching 1 or 10 isn’t going to make a lot of difference in performance of your WordPress site.

The problem is with doing complex meta queries on existing custom fields; that’s when your site would see a performance hit. Obvious, isn’t it?

Also, like @dotwired said, if your pages are cached properly, any possible performance hit can be contained.