Your website looks broken on mobile because it is not fully responsive. The layout was built and checked for a desktop screen only, so on a phone the text, images, menu and buttons do not fit or do not work properly.
The fix: make the layout adjust to every screen size, then test it on real phones. Check the mobile view of your page builder or theme, fix fixed-width sections and oversized images, confirm the viewport tag is present, and test the menu, forms and checkout. A developer can do this for you, or if you built the site yourself with AI, you can fix it with the prompt in Option 2 below.
This guide covers what goes wrong, what you can lose, how to test your site in five minutes, and how to fix it on each platform.
What You Can Lose When Your Website Breaks on Mobile
A large share of visitors open your website on a phone, so a broken mobile layout directly costs the business:
- Enquiries and sales. A hidden or tiny call button, contact form or Add to Cart button means the customer cannot take the next step.
- Customer trust. A messy website makes the business look careless, so visitors leave before they read your services.
- Google rankings. Google mainly uses the mobile version of a page to index and rank it, so a poor mobile experience can hold your rankings back.
- Ad budget. Many clicks on Google and Meta ads come from phones. Sending them to a broken page wastes money.
- Checkout conversions. In online stores, a hard-to-use cart or checkout on mobile is where orders are lost.
- Repeat customers and referrals. People do not come back to, or recommend, a website that was frustrating to use.
What “Broken on Mobile” Actually Looks Like
Check whether you recognise any of these on your own site:
- Text is tiny and you have to zoom in to read it
- The page scrolls sideways (left and right) when it should only scroll up and down
- Images are cut off, stretched, or overlapping the text
- The menu doesn’t open, or opens but can’t be closed
- Buttons are too small or too close together, so you tap the wrong one
- Two columns are squeezed side by side instead of stacking one below the other
- A popup covers the whole screen and the close button is out of reach
- Forms are hard to fill because the fields are cut off
- The page loads slowly on mobile data
If you see even two of these, your website is not fully responsive.
What Does “Responsive” Mean?
A responsive website automatically adjusts its layout to the screen it is shown on. On a laptop you might see three columns side by side. On a phone, the same content stacks into one column, the text becomes comfortable to read, and the menu turns into a simple tap-to-open button.
The content stays the same. Only the layout changes to fit the screen.
A website that is not responsive keeps the same desktop layout everywhere, so on a phone everything is squeezed or cut.
Why Websites Break on Mobile: The Real Causes
This is what we most often find when a client sends us a “my website looks broken on phone” problem.
1. The website was designed for desktop only
The designer or developer built and approved everything on a large screen and never properly checked the mobile version. This is the most common cause by far.
2. Fixed widths instead of flexible ones
If a section is told to be exactly 1200 pixels wide, it will not shrink to fit a 390-pixel phone screen. Flexible layouts use percentages and max-width rules so content adapts.
3. A missing or wrong viewport setting
Every responsive page needs a small line of code (the “viewport meta tag”) that tells the phone how to scale the page. Without it, phones show a tiny zoomed-out version of the desktop site.
4. Page builder settings only done for desktop
Builders such as Elementor, Avada, Divi and similar tools let you design separately for desktop, tablet and mobile. Many sites are only finished in the desktop view, and the mobile view is left with default or broken settings.
5. Large images, sliders and videos
Oversized images and heavy sliders don’t resize properly on small screens, and they make the page slow on mobile data.
6. Custom code or plugin conflicts
A custom snippet, an old plugin, or a theme update can break the mobile layout while the desktop view still looks fine.
7. Tables, embeds and fixed-size elements
Wide tables, embedded maps, forms, and videos with fixed sizes are a common reason for the sideways-scrolling problem.
8. Websites built quickly with AI or templates and only tested on desktop
AI website builders and AI-generated code can produce a nice-looking desktop page very quickly. But if nobody checks it on a real phone, small issues slip through, like overlapping sections, oversized headings, or menus that don’t work.
This is true on every platform: WordPress, Shopify, WooCommerce, or a custom-coded website. The platform is rarely the real problem. Skipping proper mobile testing is.
How to Check Your Website on Mobile in 5 Minutes
You don’t need to be technical for this.
- Open your website on your own phone. Scroll the full homepage, then open two or three inner pages.
- Test it on a second phone, ideally a different brand or an older model. Ask a friend or family member. A page that looks fine on a new phone can break on a smaller one.
- Use your laptop browser’s device view. In Google Chrome, right-click the page, choose Inspect, then click the small phone and tablet icon. You can switch between phone sizes.
- Rotate your phone to landscape and check again.
- Run your site through Google PageSpeed Insights (pagespeed.web.dev) and read the mobile results. It also shows speed problems that hurt mobile visitors.
- Test the important actions: open the menu, tap the call button, fill the contact form, add a product to the cart, and complete checkout.
Write down everything that looks wrong. A clear list makes the fix much faster, whoever does it.
How to Fix a Website That Looks Broken on Mobile
There are two practical routes: ask your developer or agency to fix it, or fix it yourself with some help from an AI tool.
Option 1: Talk to your developer or agency
If your website was built by a developer, this is the best first step. Don’t just say “the site is broken on mobile.” Send a clear message with:
- Screenshots or a short screen recording from your phone
- The page links where the problem appears
- Your phone model and browser (for example, iPhone 13 with Safari, or Samsung with Chrome)
- What you expected to see
A good developer will fix the layout for every common screen size, test it on real devices, and confirm back to you. If your developer cannot fix it or is not responding, a different developer can take it on, as long as you have access to the website.
Option 2: If You Built Your Website With AI
AI website builders and AI-generated code often look perfect on desktop but are rarely tested on a real phone. You can ask the same AI tool to fix the mobile layout. Take a backup first, paste your code, and describe the exact problem.
Copy this prompt:
“My website looks fine on desktop, but on mobile (390px wide) the page scrolls sideways and the layout is cut off. Here is my HTML and CSS: [paste code]. Find what is causing it and give me corrected CSS so the layout is fully responsive on phones, tablets and desktops.”
Always test the result on a real phone before publishing. We cover more prompts for WordPress, Shopify and custom code in a separate full guide: How to Fix a Mobile-Broken Website With AI: Prompts and Steps.
Fixes by platform
WordPress
- Switch your page builder to its mobile view and review every section, not only the top of the page.
- Check the theme settings for responsive and mobile options.
- Deactivate recently added plugins one by one to find a conflict.
- Compress and resize large images, and replace heavy sliders with a single optimised image where possible.
- Make sure your theme and plugins are up to date and take a backup before updating.
Shopify
- Use the theme editor’s mobile preview on every template: home, collection, product, cart.
- Remove or replace apps that add fixed bars, popups or widgets which cover content on mobile.
- Check that the theme is up to date, or consider switching to a well-reviewed responsive theme.
WooCommerce
- Test the full buying journey on a phone: product page, cart, checkout and payment.
- Make sure checkout fields, coupon boxes and payment buttons are large enough to tap.
- Review any custom checkout plugin or custom CSS, as these often break first.
Custom coded or AI-built websites
- Confirm the page contains the viewport tag:
<meta name="viewport" content="width=device-width, initial-scale=1"> - Use flexible widths (percentages,
max-width: 100%) instead of fixed pixel widths. - Use CSS flexbox or grid with media queries so layouts change at tablet and phone sizes.
- Make sure images use
max-width: 100%andheight: auto.
A Mobile-Friendly Website Checklist
Use this as a final check before you call the work complete:
- Text is readable without zooming
- No sideways scrolling on any page
- Menu opens, closes and links work
- Buttons are large enough to tap with a thumb
- Images fit the screen and are not stretched
- Forms are easy to fill and submit
- Popups can be closed easily
- Phone number and call button work with one tap
- Pages load quickly on mobile data
- Tested on at least two real phones, not only on a laptop
Check Your Website with Google PageSpeed Insights
Want to find more issues with your website? Use Google PageSpeed Insights to test your website on mobile and desktop. It highlights potential problems with performance, accessibility, SEO, and best practices, along with suggestions for improvement. Learn more.
How to fix the issues: Run the test, review the recommendations, and copy the results into your preferred AI tool to get help identifying possible fixes. You can also share the report with your developer to resolve the issues safely.
Tip: Always test your website again after making changes to confirm that the fixes work correctly on mobile and desktop.
What We Do at Sarvantic
When we build a website, we design and test the mobile version from the start, not as an afterthought. We check every page on real devices, because a preview on a laptop never shows everything. If you already have a website that looks broken on phones, we can review it, list exactly what is wrong, and fix it, whether it is built on WordPress, Shopify, WooCommerce, or custom code.
Frequently Asked Questions
Why does my website look fine on my laptop but not on my phone?
Usually because it was designed and approved only on a desktop screen. The mobile layout was either never set up properly or was broken later by a plugin, a theme update or custom code.
Can I make my WordPress website mobile-friendly without coding?
Often yes. Most modern WordPress themes and page builders have a mobile editing mode where you can adjust font sizes, spacing, columns and image sizes. If the problem comes from custom code or a plugin conflict, you may need a developer.
Is a broken mobile layout bad for SEO?
It can be. Google mainly uses the mobile version of a website for indexing and ranking, and visitors who leave quickly because the page is hard to use send a poor signal. Fixing mobile problems helps both rankings and enquiries.
Can AI fix my website’s mobile layout?
AI tools can be very helpful for finding and fixing layout and CSS problems, especially if you give them the exact code and a clear description. But they are not perfect. Always keep a backup, test on a real phone, and check the full page after each change.
How much does it cost to make a website mobile responsive?
There is no fixed price, because it depends on the number of pages, the platform and how much of the layout needs work. The best way to know is to get a short review of the site and a clear quote.
Final Thoughts
Your website is often the first impression a customer has of your business, and for many of them that impression happens on a phone. A website that looks great on a laptop and broken on mobile quietly costs you trust, enquiries and sales.
The good news is that it is fixable. Check your site on a real phone today. If you find problems, send clear screenshots to your developer, or use an AI tool carefully with a backup in place.
