If you change themes or even switch away from WordPress, you may experience a drop in rankings.
This happens when something changes on the site that initially made it rank.
To maintain your ranking, make sure to do the following:
Use the same permalink structure
A permalink structure binds the link displayed in Google Search results to the corresponding content on your page.
If you change it, the content will return 404 errors and eventually be deindexed.
It’s strongly recommended that the permalink structure remains the same. If, for whatever reason, it needs to be changed, it’s crucial that all indexed pages need to be redirected correctly to their new links.
Most SEO plugins will help with that part if they were already installed before changing the permalink structure.
Avoid making drastic changes to the content itself.
Let’s start with the facts. Content on the old theme or platform helped the website reach its current rank.
Switching platforms or themes simultaneously and making drastic changes might result in a ranking drop.
There is the algorithm part. When ranked, the search engine knows precisely where each piece of valuable information was initially located. Relocating could make the page less relevant to the search.
The user experience part. The old structure has proven to help visitors to stay enough on the page and consume its content. A change could result in shorter visits, for example, or early exits.
Understanding what made pages rank is important. Making progressive changes while monitoring the rank change should help make the transition safer.
Don’t change the content above the fold.
It is not uncommon for themes to feature a large hero image or section, which will push written content below the fold.
The content above the fold could sometimes be the reason for a page ranking. The page might become less relevant to the searched keywords if it has less content.
Maintaining the same content is the way to go. If it must change, rephrase it to reduce the word count while keeping the same meaning rather than pushing it below the fold.
Keep existing schema markup from the previous site if it exists.
Some themes have their schema implementation. Ensure the schema markup is ported to a schema plugin if that is the case.
Performance and other core web vitals should at least remain similar in any new theme or platform
The performance of the site now is now a ranking factor.
This will not have a major impact since its importance is less than the relevance of the content to the search query and the backlinks that support it.
However, it might influence the position in search results.
Ensure that the new theme or platform is fast and performs better than the previous one.