Browser support: which browsers we test and why
How we decide which browsers and devices a business website must work in, what works everywhere by construction, and what we test by hand before every launch.
The short answer
Browser support used to mean building the same site several times for browsers that disagreed about everything. Modern browsers update themselves, agree on the web standards, and publish a shared baseline of what works everywhere, so a site built to those standards works in all of them. The differences that remain are at the edges: older devices that no longer receive updates, in-app browsers inside social and messaging apps that behave a little differently, unusual settings and assistive technologies. Our policy is to support the current and previous major versions of the main browsers on phone and desktop, to test by hand on real devices covering the most common combinations in the site’s own analytics, weighted towards phones, and to build with progressive enhancement so that an older browser still gets a working site without the newest refinements rather than a broken one. The policy is written down for each site, so the business knows what is promised and what is best effort.
What is supported and how
| Category | Policy | How it is checked |
|---|---|---|
| Current and previous major versions of the main browsers, desktop and mobile | Fully supported: layout, interactivity, forms, performance | Automated cross-browser checks in the pipeline; manual test before launch |
| The default phone browsers on both major mobile platforms | Fully supported and tested first | Real devices, mid-range and flagship, on mobile data |
| In-app browsers in social and messaging apps | Supported; tested for the common ones | Real devices, opening links from the apps |
| Assistive technologies: screen readers, magnification, voice control | Supported through standards and accessibility testing | Manual tests with a screen reader on phone and desktop |
| Older browser versions still in use per analytics | Working content and forms; newest visual features may degrade | Spot-checked; progressive enhancement guarantees the base |
| Retired browsers | Not supported | None; content still renders as HTML |
| Basic, readable print styles | Manual check on key pages |
How we decide and test
- Read the site’s analytics by browser, version and device, or the market’s typical mix for a new site.
- Write the support policy: fully supported, best effort, not supported.
- Build to baseline features; treat newer features as enhancements with fallbacks.
- Run automated checks across browsers in the pipeline on every change.
- Test by hand on real devices before launch: the top phone and desktop combinations, in-app browsers, a screen reader.
- Watch error monitoring after launch for browser-specific failures.
- Review the policy yearly as the analytics shift.
Why this is simpler than it used to be
Self-updating browsers mean most visitors are on a recent version within weeks of a release. Standards convergence means the same code behaves the same way. Progressive enhancement means the remaining differences degrade gracefully rather than breaking. The result is that browser support is now a written policy, a pipeline check and a real-device test before launch, rather than a permanent tax on every feature.
What this means for you
A site built to current standards with progressive enhancement works in all modern browsers by construction. What remains is a written policy drawn from your visitors’ actual browsers, automated checks in the pipeline, and hand testing on real devices including the in-app browsers and a screen reader before launch. Ask for the policy and the device list; they are short, and they are the difference between assumed and verified.
Frequently asked questions
Do you still support old browsers like Internet Explorer?
No, and neither does its maker; it has been retired for years. Supporting it would mean building the site down to standards from a decade ago and slowing it for everyone else. A site built with progressive enhancement still shows its content in very old browsers, because the content is plain HTML, but layout and interactivity are not tested or promised there.
Which browsers matter most for a business site?
Whatever your visitors use, which analytics shows by browser and device. For a European business site that means the default phone browsers on the two major mobile platforms, the major desktop browsers, and the in-app browsers inside social and messaging apps, which behave differently and are often forgotten. The testing list is drawn from the analytics, weighted towards phones.
What happens when a browser updates and something breaks?
Rarely, because browsers now ship changes carefully and standards-based sites are insulated, but it happens. Monitoring shows errors rising, the pipeline's cross-browser checks catch it on the next build, and the fix is deployed through the normal process. Keeping the site's dependencies current is what keeps this rare, because outdated libraries are where browser changes bite.
Sources
- MDN Web Docs: Baseline (accessed 2026-09-12)