Your service must be universally accessible. This means building it to work on every browser or device that your users access it on.
Test for compatibility
Technology is always changing, so users’ experience of your service will vary according to the technical capabilities of their browsers and devices.
Different browsers handle technologies like CSS, HTML and JavaScript in slightly different ways. It’s fine if there are small, visible differences in how a page renders - as long as it does not make it harder for the user to understand the content or interact with the page.
Services do not have to look perfect in every browser. But users must be able to access and use all the information and features they need, regardless of which browser they use.
Use progressive enhancement to give your service the best possible chance of working for the majority of your users.
Browsers to test in (from February 2026)
You should test your service in these browsers:
| Operating system | Browser |
|---|---|
| iOS | Chrome (latest stable version) |
| Safari (on supported versions of iOS) | |
| Edge (latest stable version) | |
| Windows | Edge (latest stable version) |
| Chrome (latest stable version) | |
| Firefox (latest stable version) | |
| Android | Chrome (latest stable version) |
| Samsung Internet (latest stable version) | |
| Firefox (latest stable version) | |
| macOS | Safari (on supported versions of macOS) |
| Chrome (latest stable version) | |
| Firefox (latest stable version) |
The list in the table represents approximately 98% of the most popular browsers used on GOV.UK.
Some users may access your service using older or unsupported browsers. You should use analytics to understand how your users access the service and decide whether additional support is needed.
Testing for services that are for government use
If your service is aimed at internal users rather than the general public you should look at your analytics data and check which browsers your users are using. Then you can then make an informed decision about which browsers to test with.
Testing with assistive technologies
You’ll also need to make sure your service works with assistive technologies.
Design for your audience
When designing your service, you should analyse your users’ choice of:
- operating systems
- browsers
- browser versions
- screen size and resolutions
- choice of mobile device
If evidence shows that your users have specific needs or extra support requirements, you can use this to make a case for not meeting these browser requirements.
For example, the trade tariff team chose not to tailor their tool to smaller screens as it’s largely used by office workers working during office hours. Equally, if your audience is likely to include those working in the public sector, there may be higher use of older, more limited browsers.
As your digital service develops, you should encourage more people to use it (this is called ‘channel shift’). You should also consider how this may affect future usage patterns. Channel shift means you must also consider your potential future audience.
Adapt to changing behaviour
Decisions about compatibility cannot be something you specify at the start of your project and then forget about. Digital services need to reflect and adapt to the changing digital behaviour of their users.
Do this by researching your users and checking statistics on a regular basis. You must also make sure there’s an obvious way for users to report problems so you can carry out additional testing and make adjustments to your service.
New products and platforms might not appear in any data, but it makes sense for you to test against them if they’re likely to be popular.
You also have to work out when to stop supporting a product or system if its popularity is declining.
Related guides
You may also find these guides useful: