Browser Support Policy
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Browser Support & Web Development Policies

TDA is committed to making our website easily accessible and consistent across supported browsers and platforms. Because it is not always possible or practical for us to fully test and validate our website using every available operating system and browser combination, we have implemented these policies to ensure support for the majority of our users.

Legacy Applications

Moving forward, all current and future applications will be developed in accordance to these policies. However, we also have several legacy applications that were developed before these policies were established, and they are not fully compliant with these policies.

We are currently working towards bringing these applications into full compliance, and in the mean time, they will indicate which configurations are supported and/or any known compatibility issues.

Third-Party Applications

In addition to developing applications and websites in-house, TDA sometimes contracts with third-party vendors to provide web-based applications; these applications may or may not be fully compliant with these policies. We are also working towards bringing these applications into full compliance.

Supported Browsers

To maximize our ability to successfully support our constituents' needs, and to enable our engineering teams to make use of new capabilities available in modern, up-to-date browsers, we made the decision to support only modern browsers, which also provide improved security and performance.

TDA also uses statistical data from web visitors and registered users, rather than generic industry data, to identify the browsers used by our target audience. We regularly review this data to determine which browsers to support. Our current policy covers over 95% of our users.

We support the latest version of Google Chrome (which automatically updates whenever it detects that a new version of the browser is available). We support the current and previous major releases of Firefox, Edge, and Safari (on macOS & iOS) on a rolling basis. Each time a new version is released, we begin supporting that version and stop supporting the third most recent version.

Internet Explorer (IE) is an outdated browser that does not fully support the latest web standards and has a number of security concerns. Microsoft replaced IE11 - the last version released - with Edge as the default browser in 2015. While most of our websites will function correctly with IE11, we recommend using a modern browser (see list of supported browsers above) to ensure a secure and fully functional experience.

You can download any of the supported browsers for free:

   General Browser Requirements

To successfully interact with our website and services, your browser must meet the following requirements:

  • The browser must be configured to accept cookies
  • The browser must be configured to execute JavaScript
  • The browser must be capable of 128-bit SSL encryption

Even if you are using a supported browser, you might not be able to use our online services if you have disabled cookies or JavaScript.

We invest time and resources to ensure that our websites and applications are consistent across each supported browser/platform combination. Minor differences in appearance such as differences in font anti-aliasing (or lack thereof) and coloring (e.g., 24-bit versus 32-bit color, different gamma between Mac OS and Windows) might be experienced, but these differences should not impact application functionality.

Other browsers might also work, but we do not attempt to resolve problems with browser/platform combinations other than those listed above. Browsers that have been developed to comply with the W3C guidelines and specifications, including mobile browsers, should operate successfully.

Development Principles and Web Standards

We attempt to minimize browser-support related issues by following three best practices:

  • Develop websites and applications using W3C web standards and according to our Accessibility Policy
  • Avoid technologies that are only supported by certain browser types (e.g., ActiveX)
  • Avoid programming implementations that are only supported by certain browser types (e.g., CSS extensions)

Mobile, Tablet, and Desktop Devices

Some of our websites and web based applications will work on both mobile and desktop devices.

However, most of our legacy applications were only designed to work on desktop devices with a keyboard and mouse. While these applications may also work on mobile devices, they may have impaired usability since they were never designed to be displayed on smaller device screens or to support touch interfaces.

With the proliferation of mobile devices in recent years though, we have shifted towards supporting both mobile and desktop devices. In some instances, we have applications specifically designed to run on mobile devices (e.g. iPhone, Android apps). Additionally, other applications have been designed to run on both mobile or desktop devices, adapting as necessary to the available screen size (mobile vs. desktop), and supporting touch interfaces as well as the traditional keyboard and mouse.

Minimum Screen Resolutions

The minimum screen resolutions for desktop and mobile devices are:

  • Desktop: 1024x768px
  • Mobile: 320x480px (portrait mode) or 480x320px (landscape mode)


Please refer to our Accessibility Policy page for detailed information.