Could this WP theme update affect my SEO?

I have created a WP theme and have already updated most of my sites.
But I have a problem with one of my sites where I had a steady daily organic traffic for 5 years, then Google took 50% of my traffic, and suddenly, 1.5 years ago, the traffic came back.
I am afraid to lose it again.
My actual traffic is between 120 and 180 daily organic.
The organic traffic is not only to my posts but also to my homepage.
My updated WP theme has a very similar layout for posts and categories.
But it has a completely different structure for my homepage.

This is my current site: MexicanRoutes/.com
And this is my new WP theme I want to use for this site: RivieraMayaTravelGuide/.com

What can I do to not losing my site's ranking and position?
I can create a homepage with a design similar to the current homepage.
The new WP theme was created only because I wanted a clean and my own theme, not because I don't like the current design.
But I would prefer a new design for the front page as well.

Should I create a new design for the front page and keep all the elements and text from the current front page?

 

Almost 800 views and zero comments
800 views and 0 help.
People write spammy posts about SEO and how clever they are, but the moment you ask for advice, everyone goes offline.
Finally, I created the homepage template like on the old site and activated the new theme.
I still need to regenerate the gallery to fix the wrong dimensions of images in sidebars on single posts, and that will take a few days at least.
Then I can create a draft and experiment with the homepage design there without it interfering with the live site.

 

Changing themes can affect your website's SEO (sometimes it does and sometimes it just has a minor impact).
I checked your website's current theme and the theme you want to have now.
The current theme has a different layout and the new theme has some scripts added to it for the other layout.
These scripts can affect the rendering and SEO.
Heading structure is also changed in the new theme.

What should you do to keep SEO safe (not 100%, but it can impact a little)?
Keep the same layout for the home page (for 1 or 2 weeks to test it)
If you want to keep the newer version for the homepage, keep the old content, internal links, and heading structure, meta tags and schema markup.
Optimize it for Core Web Vitals, especially for the Home page. (Pay attention to the CLS, LCP and FID.
Preserve the same URLs and URL structure.
Optimize xml sitemap
Optimize the robots.txt file.
Do not forget to take the old website backup before proceeding further.
Your current website is mobile-friendly, so pay attention while switching to the new theme (it must be responsive too).
Check the Analytics, which page users visit the most and try to keep the same design or a similar one so the users can easily navigate to your website.

 

Thanks.
I can’t revert to the old version anymore.
I do have backups and can restore everything in case of an emergency.
But I can’t just switch the theme back with a single click.

This is the old version of my site:
https://web.archive.org/web/20250317072514/https://mexicanroutes.com/
I wanted to make it look like this site:
https://rivieramayatravelguide.com/

I’ve already activated the new theme.
This is my site now:
https://mexicanroutes.com/
To avoid a sudden and drastic change, I created a homepage template for the new theme that’s similar to the old site’s homepage design.
Now, I’ll wait a few months while I continue testing the site with the new theme and fixing minor issues (regenerate gallery etc).

Eventually, I want the homepage to look like this:
https://rivieramayatravelguide.com/

I think I need to keep all the current elements and adapt them to the new homepage design.
I’ve created a layout sketch to follow.
Am I right? Because I think that if I remove even one line of text from the old design, it could affect my SEO.

I didn’t understand what you meant.
What scripts are you referring to?
Do you mean the heading structure?
Are you talking about the whole site, or just the homepage?

So, by now, the new theme is already activated.
I will wait a few months to be sure the site is running smoothly.
And only then will start to redesign the Homepage.

 

I was talking about the JS libraries.
It will block your website rendering and also slow down the website loading time.

And, I mentioned it to check so you can avoid any serious SEO issues.

 

I have some JS for the homepage slider and a few more elements.
I don't think the site is rendering too badly.

• https://pagespeed.web.dev/analysis/https-mexicanroutes-com/ovgl75oggl?form_factor=mobile
• https://pagespeed.web.dev/analysis/https-mexicanroutes-com/ovgl75oggl?form_factor=desktop

I will learn later how to optimize it, but currently the site is working even better than with the old theme.
The problem is how to move all elements from the current homepage to a new layout.

 

94 is a great score and SEO is 100, that's great either.

 

Desktop 94
Mobile 62

 

After changing the theme, Bing, DuckDuckGo, and Yahoo lost about 1/3 of their organic traffic, but they are already recovering and regaining it.
However, Google lost between 80% and 90%...
Google is the most useless search engine, it doesn't search for pages but does who knows what instead.
All my URLs remained the same, the code was improved and cleaned up, but Google seems to be busy comparing class name changes, divs, and other things it shouldn't even be concerned with.

 

It's been 4 weeks, Google has returned some of the traffic, but it's coming back very slowly, once again proving that Google is garbage.
I only changed the theme, all the URLs stayed the same.
I even recreated the front page in the old format to preserve all the old text.
My new theme is lighter, even though the old one was already well optimized by me.
But with the new one, the PageSpeed score is even higher.
So what's the problem if the URLs are the same, the posts are the same, everything is the same?
Why did the traffic drop so hard?
The job of a search engine is to search, not to evaluate the HTML structure of a site.
In any case, one day would have been enough to scan the whole site and recognize the old content among the new classes and divs.
Why does changing class and div names affect the content and the ranking of posts?
Google is just doing the wrong job, poking into things search engine shouldn't be involved in...
I could understand if the new theme would load slowly, if I changed URLs, or moved to another domain.
The strangest thing is that now more visits are coming not to the posts that used to rank at the top, but to other ones...
So, Google stopped liking the post just because I changed the theme?
But it’s the same content, the same keywords...
I honestly don’t understand.

After I changed the theme, my Domain Authority (DA) finally increased to 30.
It jumped from DA 26 to DA 30 after the theme switch.
Finally, after 6 years of no growth, the DA has reached 30.

 

Ups, after 1 day, MOZ set the DA again to 26
wtf?

 

if the homepage already gets organic traffic, i’d be very careful about changing its structure too much. google may treat a big design/layout shift (especially above-the-fold content) as a change in page intent. best to keep key elements: headings, internal links, main text, and metadata. you can redesign visually, but try to keep the content and html structure similar. maybe A/B test or do the changes in stages. also, don’t forget to monitor gsc closely after launching the new theme.

 

The homepage was getting organic traffic.
After changing the theme 4 weeks ago, I lost 50%.
Bing, Yahoo, and DuckDuckGo recovered in 2 weeks.
Google started recovering this Monday.
Traffic is almost back.

Now I just need to redesign the homepage template only.
But I’m not sure how to adapt the old text to the new layout in a natural way.

• This is how the homepage looked before I changed the theme: https://web.archive.org/web/20250405223507/https://mexicanroutes.com/
• This is the current homepage with the old layout preserved: https://mexicanroutes.com/
• This is what I want: https://mexicanroutes.com/mexicanroutes/

You can see I added some important keywords to the category menu under the slider.
Next is a section with 8 random cities that change on each load, but I’m thinking of replacing them with 8 fixed popular destinations.
Then I added more keywords: Pre-Hispanic Mexico, Colonial Mexico, and Modern Mexico.
After that, there's a section showing 2 random images from the “archaeological sites” category, but maybe better to either fix 2 or rotate the top 10 posts.
Then comes the suggested routes section.
Then comes a new section: All you need to know about Mexico and What is Mexico famous for — I might rename or improve that part.
The last section is the blog, but I’m not sure if it’s better to show the latest 6 posts or it's better to show the fixed 6 most popular topics (The best time to visit Mexico, What is Mexico famous for, etc).
Part of the old content ("What is Mexican Routes"), I moved to the footer.

The problem is that the old version still has a lot more text: Mexico quick facts, Best time to visit, Is Mexico safe, etc.
I have no idea where to place all that in the new design without cluttering it.

I also need to find and resize 1500 old images, and I have to keep the same URLs since many sites link to them, so I need to carefully regenerate the gallery.
It all will take at least a few months, and only then I plan to update the homepage.

 

Hello, your clearest observation should be to check if there's been any change in your URL structures. If you haven't created any 404 pages and your URLs haven't changed, there won't be any problems.

 

Thanks.
Yes, I kept all URLs and my site has a 404 page.

After changing the theme, my site began losing traffic about three days later.
The drop continued steadily for around 10 days, and then it started to recover.
Before the theme change, daily traffic was around 190 visits.
As it recovered, it climbed back up to about 170 per day over the next two weeks and continued growing.

Then, suddenly, traffic dropped to 100 per day (even lower on weekends).
Google used to bring in around 100 visits per day, and now it's down to just 30-40.

I don’t think the drop is related to the theme change, because the site has already started recovering.
Before the sudden drop, I saw the same posts ranking at the top of organic results as before the theme change.
But after the sudden drop, I don't see any "top" - each day Google chooses a different random post for traffic.
I’m more than sure this happened because of a parasite-like service - spamhaus.org.

I have 30 domains on my server, and on July 10, something happened: the server sent 8 emails from each domain.
That’s a total of 240 emails, but they were only sent to me, to the registrant email, and no one else.
Spamhaus.org, this useless parasite site, detected this activity and added my server’s IP to their spam list.
After spamhaus.org listed my IP on their spam list, most of my emails stopped reaching recipients.
My emails started bouncing back with spam warnings and references to spamhaus.org.
That’s how I found out about them.
I removed my server's IP from their spam list, but the damage was already done.
My IP was in thier spam list for more than 1 week.
Most likely, Google detected that my domain was listed in their database and tanked my traffic.
Google is fast at finding gossip and lies on the internet, but they’ll never admit their own mistakes.
So whether my traffic will return, I honestly don’t know… damn spamhaus.org.

And no, this drop wasn’t caused by the Google core update in June.
All Google core updates have always had an impact on my site either on the release day or the next day, and never toward the end of the rollout.

I’m sure this traffic drop was caused by spamhaus.org - a parasite online site and service.
By the way, they have over 100 reviews and all of them are negative.
They label as spammer even the sites with no email on their domain.

 

Finally, Google traffic dropped from 100-120 daily to 20 daily.
Have no idea what the reason is - June Google core update, which struck me at the end of the rollout, the f#cking spamhaus.org or whatever else..

 

You're experienced enough to know that their traffic fluctuates with every update. Coupled with the new AI model they're using - it's a mess. Normally, traffic always returns to its previous level, and sometimes surpasses it, within a couple of weeks to a couple of months. My experience anyway.

 

After changing the theme, the site was restored... well, almost.
Organic traffic reached 170 daily organic (before switching to the new theme, traffic was over 180+).
But it started to drop two days after spamhaus.org added it to their spam list.
I don’t understand how a parasitic site like spamhaus.org still exists and has a reputation.

 

I asked Grok, it said: There's no clear indication that Google integrates Spamhaus data into its core ranking algorithms. Any impact would likely be secondary, such as a site being penalized for hosting malware or phishing content, which aligns with Google's broader security policies rather than a direct reliance on Spamhaus.

 

I understand, but after Spamhaus.org added me to their spam list, my emails stopped being delivered.
So Spamhaus isn’t just some random site, it carries some weight.
But if you look at the reviews about them, it’s all negative…
But the fact is, my clients stopped receiving my emails while I was listed by Spamhaus.
A week after I removed my IP from their list, my emails started working normally again.
So they affect a site's reputation in some way.
Maybe Google doesn’t take them into account directly, but probably through some third-party services.
None of Google’s core updates ever had an impact on my site at the end of their rollout.
Whenever Google started a new core update, my sites felt it on the very first day.

BTW, my site had no security vulnerabilities.
The issue was technical and related to the server configuration.
I received a few notifications through each of my 30 domains hosted on the server.
All emails were sent via server.mexicanroutes.com, and they were sent only to me, to my email registered with my hosting provider.
Besides, Spamhaus removed my IP immediately after my request, which indicates that there was no spam issue on my side.
The problem is that I found out about it a week later, so many services could have detected my IP on the Spamhaus blacklist during that week.