You're getting messages from customers saying your website looks weird on their phone. Buttons are cut off. Text is tiny. Images are stacked on top of each other. The menu is nowhere to be found. Meanwhile, you open your laptop, check the site yourself, and everything looks completely fine. So what's going on?
This is one of the most frustrating website problems a business owner can run into — partly because it's hard to see with your own eyes, and partly because it's happening right now, to real customers who are trying to do business with you. Every person who lands on your site from their phone and sees a broken, jumbled mess is a potential customer walking out the door.
The good news is this is a fixable problem. It doesn't mean your whole website is broken. But it does mean something needs attention, and the longer you leave it, the more it costs you.
What Causes a Website to Look Broken on Mobile Phones
The most common culprit is something called responsive design — or rather, the lack of it. A responsive website is one that adjusts its layout depending on screen size. When that responsiveness breaks down or was never properly set up to begin with, your site can look great on a wide desktop monitor but fall completely apart on a phone screen.
Here are the most common reasons this happens:
A theme or template update went wrong. If you're on WordPress or Shopify and a theme update was applied recently, it may have overwritten settings or introduced code that doesn't behave correctly on smaller screens. This is more common than most people realize — you can check out what happens when a website breaks after an update for more context on how that plays out.
Someone edited the site and introduced a problem. Even a small CSS or layout tweak can have unintended consequences on mobile. If you or someone else recently made changes to the site, that's often where the trail leads. Website Broke After I Changed Something? walks through exactly how that kind of thing happens.
Third-party scripts or plugins are interfering. Ads, chat widgets, pop-ups, and embeds can all mess with how your page renders on mobile. Sometimes a plugin update changes how something loads, and mobile screens are the first to show the damage.
The original design was never mobile-friendly. Older websites built before mobile-first design became the standard often have this problem baked in. If your site is more than a few years old and was never properly updated, it may simply not be built to handle modern phone screen sizes.
Browser-specific quirks. Safari on iPhone, in particular, handles certain CSS properties differently than Chrome or Firefox. A site can look fine on an Android phone but completely broken on an iPhone — or vice versa. If this sounds familiar, Website Broken on iPhone Safari gets into the specifics of why that happens.
What Fixing a Mobile Display Problem Actually Involves
Fixing a site that looks broken on phones isn't usually a single click. Depending on the cause, it can involve several different types of work.
A developer will typically start by opening your site across multiple devices and browsers — a real iPhone, Android phones of different sizes, tablets — and documenting exactly what's breaking where. This diagnostic step matters a lot, because mobile issues can be inconsistent. Something might only break on iPhones running a certain iOS version, or only when the screen is below a specific width.
Once the problem is identified, the fix usually involves editing the CSS (the code that controls how things look) to add rules that tell the page how to behave on smaller screens. This might mean adjusting font sizes, fixing navigation menus that collapse incorrectly, correcting image sizing, or restructuring page sections so they stack properly instead of overlapping.
If a plugin or third-party script is causing the issue, that element needs to be isolated and either replaced, updated, or removed. If a recent theme update is to blame, the developer may need to roll back to a previous version or manually patch the affected code.
The work is usually not glamorous, but it requires someone who knows what they're looking at. Guessing at CSS values without understanding what's wrong is more likely to create new problems than solve the existing one.
Signs This Is Your Issue
You don't have to wait for customers to complain to suspect you have a mobile display problem. Here are signs worth paying attention to:
- A customer mentions your site looks "weird," "hard to use," or "all jumbled up" on their phone
- You notice your traffic has dropped, especially from mobile devices (check Google Analytics if you have it set up)
- You pull up your site on your own phone and something looks off — even slightly
- You recently updated a plugin, theme, or made changes to the site design
- Your site hasn't been updated in several years and was built before mobile responsiveness was standard practice
- Google Search Console is showing mobile usability errors (if you have access to it)
Any one of these is a reason to take a closer look. And if customers are actively telling you, that's not a sign to put it on the to-do list for someday — those are real lost sales happening in real time.
Should You Try to Fix It Yourself?
If you're comfortable in your website's backend and you have a clear, simple hunch about what changed (say, you updated a plugin right before this started), you might be able to undo that change and see if it resolves things. That's a reasonable first step.
But for most business owners, mobile display issues are not a DIY fix. The problem is that CSS and responsive layout issues require a working knowledge of how browsers interpret code on different screen sizes. Without that background, it's easy to spend hours making changes that don't help — or accidentally break something else in the process.
There's also the diagnostic challenge. You might fix how it looks on your phone and not realize it's still broken on a different device or browser. A developer will test across multiple environments before signing off.
If you're not sure where to start or you've already tried a few things with no luck, here's a straightforward guide on what to do when your website is broken and you don't know why. It's a helpful starting point before you decide who to call.
Common Questions About Mobile Website Display Problems
Why does my website look fine on my computer but broken on phones? Your computer monitor is wide enough that your site's layout doesn't have to change much to fit it — but phone screens are much narrower, and that forces the layout to adapt. If the responsive code that handles that adaptation is missing or broken, the layout falls apart on mobile even while looking perfectly fine on desktop.
Can a mobile display problem hurt my Google ranking? Yes, it can. Google uses mobile-first indexing, which means it primarily looks at the mobile version of your site when deciding how to rank it. A site that's broken or hard to use on phones can see lower search rankings over time, on top of the direct business it's already losing from frustrated visitors.
Is this a problem with my hosting, or my website itself? Almost always it's the website itself — specifically the theme, template, or CSS code that controls how the site looks. Your hosting provider is responsible for keeping the site online and loading quickly, but the visual layout on different screen sizes is entirely determined by how the site is built.
How long does it take to fix a mobile display problem? It depends on what's causing it. A single CSS fix might take less than an hour. If the issue is widespread — like a theme that was never properly designed for mobile — it could take several hours of work to test and address across different devices and screen sizes. A developer should be able to give you a clearer estimate after a quick look at the site.
What if only some pages look broken on mobile, not all of them? That's actually a useful clue. If the problem is isolated to certain pages, it often points to something specific on those pages — a particular plugin, an embedded element like a video or map, a custom layout section, or content that was formatted differently. It's usually easier to fix than a site-wide issue because the scope is narrower.
The Faster Path
If customers are already telling you your website looks broken on their phone, you've moved past the "keep an eye on it" stage. You need someone who can look at it, figure out what's wrong, and fix it — without a long back-and-forth about scope, hourly rates, or retainers.
That's exactly what Rune is built for. It's a flat-rate website repair service, which means you know what you're paying upfront, there's no hourly meter running, and fixes are handled by people who do this every day. If you've been putting off dealing with this because you weren't sure how much it would cost to fix or how to find someone you can actually trust, Rune takes both of those questions off the table.
You describe the problem, it gets looked at, and it gets fixed. No jargon, no project proposals, no waiting weeks for a developer to get back to you. Just a working website that doesn't embarrass you when a customer pulls it up on their phone.
If that sounds like what you need, head over to runeintel.com and get started.