If we look at functionalities, we do see a difference. Then Rank Math is clearly more complete. Below is an overview of the different in functionalities. I have listed the most important ones and will elaborate on them further.
Differences Yoast vs Rank Math
Of course, you can use both SEO plugins to customize your Meta Title and Description. But that seems to make sense to me. The first difference is that Rank Math allows you to enter more than 1 keyword. This means that you can let the plugin scan the page for more than 1 search term. So you can see if your page is optimized for relevant keywords. 100% optimization on more than 1 keyword is of course difficult, because you only have 1 URL and 1 Meta Title + Description. But you can see if there is room for improvement on the relevant other keywords.
Another point is that Yoast SEO works with a traffic light (red, orange, green) and Rank Math with the same colors, but with a number from 1-100. This gives you a better idea of how your page ranks. For example, if you are at 79, you are still orange, but at 80 it is green. That difference is very small and maybe not worth addressing. But if you're at 61, then it might be worthwhile, that difference is pretty big. So you don't see this difference with Yoast, and that's still useful to know.
Linking SEO plugins
You can add a sitemap with both and link to Google Search Console. The link with Google Search Console has your information directly from Search Console. So you can see within WordPress due how you score and how people know to find your business. If you want to go more in depth, then I recommend you just use Google's tool, obviously there is much more in there.
SEO plugin site analysis
Rank Math also has an analysis feature, Yoast SEO does not. With this, the plugin scans your website and gives you feedback on what could be better. For example, you can easily see if there are pages where your main search term is not yet included in the Meta Title, without having to go through all your pages. Here you also get some information about speed, security and social media links. Things that you can't see as easily at the front end, but are now insightful.
Another difference is the ability to set default SEO for images. What I often see is that images are not provided with an Alt text and a good title. That's a shame because Google can't tell from an image what it says. You have to set that up Google and with these 2 details you can do that. But it is not a standard process within WordPress to provide the image with this after uploading. You have to do that manually, and it's often forgotten. With the option offered by Rank Math you can have this filled in automatically. You don't have to do it yourself anymore. Make sure you change the filenames before uploading so you can use them for the appropriate Alt Text and Title.
Internal Link Suggestions
Internal links are important for SEO. It indicates which content belongs where. For visitors it is an easy way to find more content on your website and for search engines it is clearer what is important content on your website.
Both plugins offer suggestions, but with Rank Math you do not need to have a premium account for this. It just falls within the free version.
Redirects in SEO plugin
Redirects might be something you are using another plugin for, or maybe you are not using it at all yet.
What does a redirect do? A redirect refers an url to another url.
For example if you have a page which you have improved but because of this the url (link) has also changed, then you can redirect the old page to the new one. The advantage of this is that Google understands that your page has been moved and the SEO value will continue. In addition, visitors from a link on another website would go to your old page, now arrive at the new one and not on a 404 page (the old one no longer exists).
It may also be the case that you are going to change the structure of your website, and also in that case you have to redirect the old sites to the new ones. This is something that is often forgotten when launching a new website. A pity because then you will lose the earned organic positions and you will have to earn them again.
Rank Math includes this by default, together with a 404 monitor. Here you can see on which url's a 404 error occurred. It may be that you have overlooked some, here you get a clear overview and you can easily create a redirect for that page.
Yoast SEO includes this in the Premium package.
Adjust permissions per role
Do you have other users in WordPress besides yourself, for example someone who creates and posts content for you? Then you can adjust the rights of the plugin per role in Rank Math. This way you can determine which things someone can or cannot control and prevent someone from (accidentally) modifying something that is not intended.
With Yoast this is not possible, for this you will have to use an additional plugin.
Schema Markup with SEO plugin
This is one of my favorite differences between Yoast and Rank Math. With Rank Math you have a lot more options to add Schema Markup to your pages, and they work well too.
What is schema markup? Schema Markup is structured data that is visible to search engines. This makes it easier for search engines to determine what kind of content it is.
You can specify per page, article or post what schema data you want to apply. Is it an article, a course, event, vacancy, product, recipe, review, video, etc, etc.? By indicating this properly, search engines like Google know better what your content is about and you can earn rich snippets with your page. Rich snippets are entries in Google that stand above all other organic entries. So they get extra attention from the users of Google!
Yoast SEO has 3 options where Rank Match has 16. So with Rank Match you can submit many more different types of content in structured data to Google. Search engines are very happy with structured data, because it makes it a lot easier to create a good ranking.
Conclusion: Best SEO Plugin for WordPress?
In addition to the above differences, there are also a whole list of other, more technical, differences. I won't discuss these further here because they are much less used. The above functionalities are the most used for website administrator. And these are also the most important to score well in Google.
If you put the features side by side you will see that Rank Math offers more than Yoast (especially in the free version). This is also the reason why my preference is for Rank Math when it comes to SEO plugin in WordPress. It works easily and pleasantly, gives more features and can help you get higher in Google.
More features within Rank Math also means fewer other plugins are needed. With fewer plugins, your website stays faster, is less prone to security issues (Rank Math can also let you update automatically) and is easier to manage.
The biggest advantage I find is the Schema Markup options Rank Math offers. With this I have seen an immediate difference in the ranking positions of several websites. By adding this information correctly you can rank better in Google. And that's what an SEO plugin is for, helping you rank higher in Google.
Switching from Yoast to Rank Math?
Switching is very easy. Rank Math has a feature to import data from Yoast SEO. So all the data you've already entered in Yoast SEO will be included in Rank Math. So transferring is easy and fast.
In addition, Rank Math can also import the redirects from other plugins. So you don't have to transfer that data yourself either. Even if you already use the Schema Markup of certain plugins, it can be imported.
This makes transferring to Rank Math easy and quick. You can reduce the number of plugins so you have less risk of outdated plugins or error messages on your website.
Are you going to switch? Then of course make a backup of your website first! Just like when doing updates, don't forget to make a backup!
Looking for software reviews? Then have a look at the website of Stackbutler. They compare lots of useful software!