- Test the browsers your visitors use: GA4 shows them under Tech details.
- On iPhone, Safari's engine sits behind most browsers, so test Safari on iOS specifically.
- Developer tools simulate screen sizes well, but real devices catch touch and form problems.
- Focus on tasks, not looks: can people read, navigate and submit a form in every browser?
What cross-browser testing is, and why it matters
Cross-browser testing means checking that your website looks right and works properly in the different browsers and devices people use: Chrome, Safari, Edge and Firefox, on desktops, laptops, phones and tablets.
Browsers follow the same web standards, but they don't implement every feature identically or at the same time. A menu, a form, a font or a layout can behave differently in Safari than in Chrome. And most people check their own site in one browser, on one device, so the problem goes unnoticed until a prospect can't submit your contact form.
You don't need to test everything everywhere. You need to test the pages that matter in the browsers your visitors actually use.
Step 1: Find out which browsers your visitors use
Open Google Analytics 4 and go to Reports, Tech, Tech details. Change the dimension to Browser, then to Device category and Operating system. This tells you your real mix: for example, mostly Chrome and Safari, a lot of iPhone traffic, a share of Edge from office laptops.
Use that to set your test list. A sensible default for most business sites:
| Browser | Device | Why |
|---|---|---|
| Chrome | Windows or Mac laptop | The most widely used desktop browser |
| Edge | Windows laptop | Common on business laptops |
| Safari | Mac | Different engine from Chrome |
| Safari | iPhone | On iOS, most browsers use Safari's engine, so this covers much of your iPhone traffic |
| Chrome | Android phone | Covers most Android traffic |
| Firefox | Desktop | Smaller share, but a different engine again |
Step 2: Choose your pages and tasks
Test tasks, not just pages. For most sites that means:
- Homepage: loads, reads well, menu opens and closes.
- A main service page: layout, images, tables, call-to-action buttons.
- Contact page: the form can be filled in and submitted, the confirmation appears and the enquiry arrives.
- Any booking, quote or download flow.
- Cookie banner and pop-ups: can be read, accepted, rejected and closed.
Step 3: Test, using free and low-cost tools
View your website on mobile with developer tools
Every desktop browser has a responsive or device mode:
- Chrome and Edge: open DevTools (F12 or Ctrl+Shift+I / Cmd+Option+I), then click the device toolbar icon. Choose a device or drag to any width.
- Firefox: Responsive Design Mode (Ctrl+Shift+M / Cmd+Option+M).
- Safari on Mac: enable the Develop menu in Safari settings, then choose Enter Responsive Design Mode.
These are good for layout at different widths. They're not a perfect substitute for real phones: touch behaviour, on-screen keyboards, real performance and some Safari-specific quirks only show on the device.
Test on real phones
Use the phones you and your colleagues already have. Between an iPhone and an Android phone in the office, you'll cover most mobile traffic. Check on mobile data as well as office wifi, because slow connections expose problems.
Test your website on iPhone from a Mac
If you have a Mac, you can connect an iPhone with a cable and inspect the page in Safari's Web Inspector on the Mac. Apple's Xcode also includes an iOS Simulator for testing different iPhone sizes.
Test on browsers you don't have
Cloud testing services let you open your site on real devices and browsers in your web browser, including older versions and devices you don't own. Most offer free trials or limited free plans; they're useful before a launch or redesign.
Step 4: What to look for
| Area | Check |
|---|---|
| Layout | Nothing overlaps, overflows or forces sideways scrolling; columns stack sensibly on mobile |
| Text | Fonts load; text is readable without zooming |
| Navigation | Menus, dropdowns and the mobile menu open, close and work by touch and keyboard |
| Forms | Fields accept input; the right keyboard appears on mobile; validation messages show; the form submits and the enquiry arrives |
| Media | Images load and scale; videos play; embedded maps work |
| Interactive parts | Sliders, tabs, accordions and pop-ups work and can be closed |
| Sticky elements | Headers and chat buttons don't cover content or form fields on small screens |
| Speed | Pages load in reasonable time on a phone on mobile data |
Fixing what you find
Record each problem with the browser, device, page and a screenshot, then fix or hand to your developer. Common causes:
- A layout breaks in one browser: often a newer CSS feature that one browser handles differently. Developers can check support on caniuse.com and add a fallback.
- A form won't submit in Safari: often a script or validation issue, or a third-party form embed. Test the form provider's own page in the same browser to narrow it down.
- Something works on desktop but not on phones: usually touch events, hover-only menus, or elements sized for a mouse pointer.
- Fonts or icons missing: a font file that failed to load, often blocked by a server setting.
When to test
- Before launching a new site or redesign: see the website launch checklist.
- After any change to the theme, menu, forms or page builder.
- After major browser updates, if something looks off.
- Quarterly, on your key pages and forms.
Questions
How do I test my website on different browsers?
Check GA4 to see which browsers your visitors use, then test your key pages and forms in those browsers. Use developer tools for screen sizes, your own phones for real-device checks, and a cloud testing service for browsers you don't have.
How do I view my website on mobile from my computer?
Open your browser's developer tools and switch on device or responsive mode. It shows your site at phone and tablet widths. Confirm the result on a real phone for touch and form behaviour.
How do I test my website on an iPhone?
Use a real iPhone where you can, because it shows true touch and Safari behaviour. On a Mac, you can also inspect a connected iPhone in Safari's Web Inspector, or use the iOS Simulator in Xcode.
Which browsers should I test my website in?
The ones your visitors use, from GA4's Tech details report. For most business sites that's Chrome, Safari (Mac and iPhone), Edge and Chrome on Android, with Firefox as a check.
Is cross-browser testing the same as mobile testing?
They overlap. Mobile testing focuses on small screens and touch; cross-browser testing covers differences between browsers on any device. Do both on your key pages.
Every guide is checked against the platform it describes before it’s published, and re-checked when the platform changes.