we also created:

What is cross-browser testing?

Cross-browser testing is a type of testing that lets you make sure that your website or a JavaScript application works correctly in all web browsers. There are so many different browsers – Chrome, Firefox, Safari, Opera, Internet Explorer, Edge – and each one of them works a little bit differently. What's more, there are many different systems – Windows, macOS, iOS, Android – and these systems are also different. They have different fonts, different graphics capabilities, different screen sizes, etc. As a result, there can be substantial differences between how your website or app works in one browser on one system compared to another browser on another system.

Why is cross-browser testing important?

Cross-browser testing is important because people use different browsers and devices to view your website. For example, someone might be using Edge on Windows 10 on a high-resolution monitor but someone else might be using Safari on an iPad. Both people will experience your website differently. To make sure your website looks great in both environments, it needs to be tested in these environments. Similarly, if you're developing a web application, someone might still be on Windows 7 and using an older browser. If you don't test your app in this browser, it's possible the app is broken because older browsers don't support certain features.

How to perform cross-browser testing?

There are two ways how you can do cross-browser testing. The first one is maintaining your own testing stack with different browser installations and mobile devices. This approach is rather expensive and time-consuming as you have to buy new devices, install browsers, maintain security updates, etc. The second way is using Browserling. At Browserling, we maintain the testing stack and keep browsers up to date so you don't have to worry about it. You can just select the browser/device combo that you need and start testing in a couple of seconds.

Try Browserling!

For a quick demo, enter your website here, and we'll open it in Edge 110 on Windows 10:

We provide Edge on Windows 10 for free but other platforms and browsers require a developer plan.

Cross-browser Testing FAQ

Do you offer macOS testing?

Yes, we offer macOS testing. We bought a bunch of Mac computers and installed various Safari versions on them. You can try Safari 18 on macOS 15 (Sequoia) right now via the widget below. Simply enter your website and click the Test now button:

Do you offer Android testing?

Yes, we also offer Android testing. We run all versions of Android Studio and offer multiple Android browsers. You can try Android right now via the widget below. Simply enter your website and click the Test now button:

Do you offer other Internet Explorer versions besides 11?

Yes, we offer all Internet Explorer versions! We run various Windows operating systems and each Windows version has a different IE version. For example, Windows XP has IE 6, 7, and 8, Windows Vista has IE 9, Windows 7 has IE 10 and IE 11, Windows 8 and 8.1 have IE 11, and Windows 10 has IE 11. Please see our Testing in Internet Explorer page for more information. Additionally, Windows 10 and Windows 11 have the new Microsoft Edge browser, which we also support.

Do I need to test on old browser versions?

Sometimes, yes. If your users are from big companies, schools, or government offices, they may still use older browsers. A site that works in Chrome 130 might not work in Chrome 80. Testing older versions helps you find problems before your users do.

Do I need coding skills for cross-browser testing?

Not at all. If you just want to see how your site looks, you can start a browser and check visually. Developers and QA testers can go deeper by checking features, JavaScript, CSS, and APIs, but anyone can use Browserling for quick tests.

How long does a cross-browser test take?

Usually just a few minutes. You pick a browser and start browsing your site. You can quickly see if things look right or if something is broken.

Can I test behind a firewall or on a local server?

Yes. Browserling offers a local tunneling feature. It lets you test sites that aren't live on the Internet yet, such as local builds, intranet sites, or apps running on your own computer.

Is cross-browser testing the same as responsive testing?

Not exactly. Responsive testing checks how your site adapts to different screen sizes (like desktop vs. phone). Cross-browser testing checks how your site behaves in different browsers. They're related but not the same.

Do I need special hardware for testing?

Nope. Everything runs in the cloud. All you need is an Internet connection and a browser. Browserling does the heavy lifting for you.

Will cross-browser testing slow down my computer?

No. The browsers run on Browserling's servers. You're just streaming the session, like watching a video. Your computer only handles the connection.

How do I test browser-specific CSS bugs?

Use developer tools inside each browser session and check which CSS rules are being applied. Some properties behave differently across browsers, so testing multiple browsers helps you quickly spot mismatches.

Can I test browser performance differences?

Yes, you can. Open the same page in multiple browsers and compare load times, animations, and script execution. Even small differences in rendering engines can affect performance.

Do all browsers support the same JavaScript APIs?

Not always. Some browsers ship APIs earlier, while others lag behind or use different prefixes. Testing ensures your app won't break if a feature isn't fully supported.

What about testing browser extensions or add-ons?

Yes, you can install extensions inside the session and check how they interact with your site. This is useful if you're building tools that depend on browser APIs or want to ensure your extension works in older browser versions.

Can I test media playback in different browsers?

Definitely. Browsers support different video and audio codecs, so testing playback across Chrome, Firefox, Safari, and Edge helps you avoid "file not supported" issues.

Do I need to test browser security warnings?

Yes. Browsers handle mixed content, invalid SSL, and insecure scripts differently. Testing lets you see how users will experience security prompts or blocked pages.

How do I test cross-browser compatibility with iframes?

Load your iframe content in multiple browsers and check for sandboxing, CORS, and sizing issues. Some browsers enforce stricter rules, which can break embeds.

Can I test browser-specific developer tools features?

Yes, you can open DevTools inside each session. This helps you debug how browsers parse HTML, apply CSS, or run JavaScript differently.

Is WebAssembly supported in all browsers?

Most modern browsers support WebAssembly, but older ones may not. Testing ensures your app has proper fallbacks for users without WASM support.

Can I test WebRTC features in different browsers?

Yes, you can. WebRTC support varies across browsers, especially with permissions, codecs, and device access. Testing helps confirm video calls or peer-to-peer connections work everywhere.

Do browsers render fonts the same way?

Not always. Each browser and OS has its own font rendering engine. Cross-browser testing helps you catch differences in kerning, line height, or fallback fonts.

How do I test browser storage APIs?

Open your app in multiple browsers and check localStorage, sessionStorage, and IndexedDB. Some browsers have stricter storage quotas or privacy rules, which can break apps that rely heavily on client-side data.

Can I test push notifications across browsers?

Yes. Some browsers handle permissions or notification styles differently. Testing ensures your notifications appear as intended and actually trigger user actions.

Do CSS grid and flexbox behave the same in all browsers?

Mostly, but older versions and some engines handle edge cases differently. Testing side by side ensures layouts don't collapse or misalign.

How do I test browser zoom and scaling issues?

Set the browser zoom level to 90%, 110%, or higher during testing. Some browsers handle scaling differently, which can reveal layout bugs.

Can I test progressive web apps (PWAs)?

Yes, you can check how PWAs install, cache assets, and run offline in different browsers. Each browser supports PWAs a little differently, especially Safari vs Chrome.

What about testing drag-and-drop features?

Browsers can handle drag events slightly differently, especially with file uploads or HTML5 drag APIs. Testing across browsers makes sure the UX feels smooth everywhere.

Do all browsers support service workers the same way?

Most modern ones do, but Safari has stricter rules and some quirks. Testing ensures caching, push, and offline features work reliably across all browsers.

How do I test browser-specific keyboard shortcuts?

Open your site in each browser and try common keyboard interactions (Ctrl/⌘ + keys). Some shortcuts may conflict with browser defaults, so testing helps you find conflicts early.

What is geo-browsing?

Geo-browsing means opening a site from a specific country or city IP address so the site thinks you're physically there. This helps test location-based content, pricing, or redirects.

Why would I use geo-browsing?

To check region-specific content like language, currency, local ads, geo-blocking, or legal notices. It shows what real users in that location see.

How does geo-browsing help with cross-browser testing?

It lets you test the same site in different browsers and from different countries. For example, you can see how Chrome in the U.S. vs. Firefox in Germany load your site.

Do I need geo-browsing for cross-browser testing?

If your site changes by country or region, yes. Testing across browsers and geographic locations makes sure you're not missing bugs for international users.

How do I pick a country or city to test?

Just choose the country and sometimes the city in the geo-browsing menu item. Browserling offers many country options and sometimes common cities for better accuracy.

Can geo-browsing show me local search results?

Yes, it helps you see search results, local landing pages, and ads as they appear to users in that region.

Does geo-browsing change my browser language or just the IP?

It changes the IP and location. Browser language stays set in the browser unless you change it. For full locale testing, set both IP region and the browser language/locale (in system settings).

Is geo-browsing good for testing laws and compliance messages?

Yes. Geo-browsing is useful to confirm region-specific legal banners, cookie notices, and privacy messages are shown correctly.

What is mobile IP testing?

That's testing your site while using an IP address that belongs to a mobile carrier and uses mobile data (such as 4G or 5G), not a regular Wi-Fi or datacenter connection.

Why test with a mobile IP instead of normal IP?

Some services treat mobile IPs differently (ads, CAPTCHA, throttling). Mobile IP testing shows how your site behaves for users on cellular networks.

Can I combine mobile IP testing with cross-browser testing?

Yes, when you enable mobile IPs, you can see how a site behaves from a real mobile connection in different browsers at the same time. For example, you can test your site in Chrome, Firefox, or Safari while it's running on a real mobile carrier network. This shows you both browser differences and network-related issues that real users might face.

Why is mobile IP testing useful for cross-browser testing?

Because browsers sometimes behave differently on mobile data vs. Wi-Fi. Testing both gives a more complete picture.

Can you test using a real mobile carrier's IP?

Yes, Browserling offers mobile IP and mobile-networked sessions for testing in realistic mobile-network conditions.

Does mobile IP testing also mimic mobile network speed and latency?

It can. If the mobile connection happens to be slower or has higher latency, then it will mimic real mobile performance, so you can spot load-time problems.

Will mobile IP testing show carrier-specific content?

If a site serves content or restrictions by carrier or mobile region, you'll see it during mobile IP testing.

Is mobile IP testing the same as testing on a phone?

Not exactly. Mobile IP testing gives the network address of a mobile carrier. For UI and touch testing, use our Android offering.

What are residential proxies?

Residential proxies route traffic through real home ISPs. The IPs look like regular home users, not data centers.

Why would I use residential proxies for testing?

Sites that block datacenter IPs or show different content to home users will behave normally with residential IPs. Good for realistic geo and anti-bot checks.

How are residential proxies different from datacenter proxies?

Datacenter proxies come from big servers and are easier to detect. Residential proxies come from consumer ISPs and usually look more "real".

Do residential proxies matter for cross-browser testing?

Yes, they let you test different browsers as if you were a real home user, which makes results closer to what actual visitors see.

Can I use residential proxies for both geo and cross-browser testing?

Definitely. Residential proxies + multiple browsers = realistic testing for real-world conditions.

Can I use residential proxies with Browserling?

Yes, Browserling supports testing from many residential proxies in multiple countries, including US and EU.

Are residential proxies slower or more flaky?

They can be slower or less stable than datacenter proxies, since they route through home ISP networks, so plan your tests accordingly.

Are there legal or ethical issues with residential proxies?

Use them responsibly. Don't impersonate people, don't create accounts at popular services, or violate terms of service. If you're unsure, contact support before wide use.

Can I upload files during a cross-browser test?

Yes. You can upload HTML, CSS, JS, images, or even zipped projects into the session. Once uploaded, you can open them in any browser version to see how they look and behave.

Why is uploading files useful for cross-browser testing?

It saves time. Instead of deploying your site to a server, you can just upload the files directly and instantly test them in Chrome, Firefox, Safari, Edge, and more.

Can I download files from a cross-browser testing session?

In most cases, yes. You can download files created or generated in the session, such as screenshots or test outputs. Depending on your plan, downloading might be limited for security reasons.

Can I upload multiple files or full projects?

Yes, you can simply drag and drop a bunch of files or directories into a Browserling session, but for the quickest uploads make it a zip first, then upload it, and extract it inside the session.

Can I open uploaded files in multiple browsers?

Yes, after uploading, you can open them with all in-session browsers (Chrome, Firefox, Safari, Edge, etc).

Do uploaded files stay after the session?

No. Everything is temporary. Uploaded files disappear once the session ends. This keeps your data private and ensures nothing is stored on the cloud servers.

Can I upload a project, run it, and then download results?

Yes. For example, you could upload a Node.js or Python app, run it in the session, and download the generated output (logs, CSV, or other files) or open the output in various browsers.

Are uploads and downloads safe?

Yes. Files only exist in your private session and vanish after it ends. Still, don't upload sensitive information unless absolutely necessary.

Is there a file size limit?

Yes, sessions have upload and storage limits. Very large files (tens of gigabytes) might fail. If you need to test big assets, split them in parts and test them separately.

Can I upload docs or PDFs for cross-browser compatibility checks?

Yes, sometimes PDFs or embedded docs render differently in browsers. Uploading them lets you see those differences quickly.

Can I upload Node.js code to test in a browser session?

Yes, you can upload small snippets or apps via the file transfer feature and run them inside the session.

What sort of Node.js files can I upload?

Simple scripts, package.json, small web apps, or single-file demos. Multi-file projects are okay as well as the file transfer feature supports folder uploads.

How do I run Node.js after uploading?

Open the command prompt or terminal in the browsing session, install dependencies (npm install) and run your script (node index.js). You can also use the session's browser to test your app's UI or API.

Can I upload node_modules or should I install them inside the session?

Better to upload package.json and run npm install inside the session. Uploading node_modules makes transfers big and slow.

Are there limits on runtime, CPU, or network for Node apps?

Yes, sessions are temporary and have resource and time limits.

Can my Node app open ports and accept external traffic?

The browsing session allows local testing inside the VM (via localhost:port). Public exposure or persistent external ports are currently restricted.

Can I set environment variables or secrets for Node tests?

You can set env vars inside the command prompt or shell, but treat sessions as ephemeral (so you'll have to re-enter vars and secrets each time you are testing your Node app).

How does uploading Node.js snippets help with cross-browser testing?

You can upload your app, run it in the session, and then test how it works across different browsers without needing to deploy it live.

Do I need to deploy my Node app to do cross-browser testing?

Not necessarily. Uploading code directly into the session lets you quickly spin up your app and test it in multiple browsers instantly.

Can I upload Python scripts or small apps?

Yes, Python files, small Flask/Django demos, and scripts can be uploaded and run in a session.

How do I run a Python app after upload?

Open the session command prompt or terminal, install dependencies (via pip), and run the script (python app.py). Then test in the browser if it serves a web page.

Can I use virtual environments?

Yes, you can create a venv in the session and pip-install packages there for cleaner testing.

How does uploading Python apps helpful in cross-browser testing?

It lets you launch your app inside the session and check how it behaves across browsers like Chrome, Firefox, or Safari without publishing it online first.

Is uploading Python code useful for early cross-browser tests?

Yes, you can catch browser-specific bugs before deployment by testing your app right in the VM.

Are there package or dependency limits?

No, but large dependencies may take a long time to install. Try to keep test apps lightweight.

Can I upload Python web apps that use databases?

You can test simple local DBs (SQLite). External database connections may need extra setup or tunneling.

Can I run background jobs or continuous processes?

Sessions are meant for short tests. Background or long-running processes will be terminated when the session ends.

How do I debug Python errors during testing?

Use the session terminal, view logs, and run the app with debug flags. You can also download log files locally and open them for further local inspection.

Do you offer automated testing?

No, at the moment we offer only manual testing, but we plan to offer automated testing soon as well.

Can you help us cross-browser test our application?

Of course! Send us an email at hello@browserling.com and we'll help you. We're experts at all cross-browser testing issues and we have the infrastructure to quickly debug and solve all cross-browser testing issues.

Do you have something for QA teams?

Yes, we do! We created Live API that lets you embed browsers in your own applications. If you have a QA process that requires going through multiple browsers before the release is approved, you can embed these browsers in the QA flow. Live API works through JavaScript and doesn't require additional installations.

What other creative uses does Browserling have?

Our users are super creative, and they have found all kinds of cool ways to use Browserling beyond just cross-browser testing. For example, you can use Browserling as a browser sandbox. With a sandbox, you can open any URL in Browserling (such as a malware URL or a phishing URL) and as you're using an isolated browser that runs in our infrastructure on our servers, you don't risk infecting your computer or network. Another creative use case is using Browserling for anonymous browsing, like a VPN service. You get a quick online browser that runs on our servers and your IP address stays anonymous. And yet another creative use case is trying various browser extensions without risk. Often, browser extensions contain bad code that collects information about you but if the extension is installed in a virtual browser, your privacy is protected. Finally, one of the most popular use cases is getting access to a remote browser without installing or using remote desktop software. We run the browsers on our remote servers and people connect to them remotely with just JavaScript.

Any additional questions?

Please contact us at hello@browserling.com or use our contact form.