Browser and accessibility support

Browser support

We currently support the following browsers:

Operating system Browser
Windows Internet Explorer 11
Edge (latest versions)
Google Chrome (latest versions)
Mozilla Firefox (latest versions)
macOS Safari 12 and later
Google Chrome (latest versions)
Mozilla Firefox (latest versions)
iOS Safari for iOS 9.3 and later
Google Chrome (latest versions)
Android Google Chrome (latest versions)
Samsung Internet (latest versions)

The starting point for our browser support is the GOV.UK Service Manual.

However, because our service has a high number of internal government users (who may only have access to older versions of Internet Explorer) we also use our own Google Analytics to extend our support where appropriate.

We have a recurring 2nd line task to review this table every six months (as the service manual is reviewed every six months). Decisions are made with input from product managers and should take into account the below considerations.

The last change to our browser support table was in September 2019 when we dropped support for IE9 and IE10 as the combined percentage of visitors to our site using these browsers was less than 1% in the past three months. As a rule we will support browsers with a share above 1%.

All reviews should have the details logged below for future reference.

Date Outcome Details
September 2019 Drop support for IE9 and IE10 ticket
August 2019 No action ticket
October 2018 Drop support for IE8 ticket
March 2018 Drop support for IE6 and IE7 ticket

Browser support considerations

Whenever the browser support table is reviewed the considerations that take place should be documented and added to the table above. This section just tries to list some common considerations that should come up when reviewing browser support.

Older versions of browsers typically require custom support; for example, frontend apps will typically have one or more additional CSS stylesheets (e.g. digitalmarketplace-buyer-frontend/app/assets/scss/application-ie7.scss). For browsers that we support, we need to keep these stylesheets up-to-date. For browsers that we used to support but now do not, it should be fine to leave the old stylesheets if the maintenance cost is negligible.

Browsers (especially older browsers but in some cases newer browsers as well) may also require javascript ‘shims’ to support newer HTML classes, such as the details tag. In cases where this is required, the GOV.UK Design System repository should be used as the authoritative source for such code.

As well as considering who needs to access our service, we also need to consider the security of our website and our users. The Digital Marketplace uses HTTPS to secure all connections, but this has an effect on the browsers we can support. Occasionally flaws are found in the HTTPS protocol, and new features or sometimes new versions are needed to maintain security for users, but these new features are not always made available on all browsers.

On such an occasion we should be notified by NCSC WebCheck, and we will then have to make a decision whether to support the new feature conditionally and allow older browsers to use the website (with the risk of increased vulnerability), or make the new feature mandatory to increase the site security (and make it more difficult for some users to access the site). This ticket from October 2018 shows an example of this decision making process at work.

We also have to take into account what our hosts GOV.UK PaaS will support. The Digital Marketplace uses the cdn-route service to manage its custom domain, which means that HTTPS configuration changes should be run past the PaaS team first.

Assistive technology support

The GOV.UK Service Manual also has guidance on which assistive technologies we should be testing with, for example the JAWS screen reader.