System baselines for an accessibility audit

You test a page, change a browser or display setting, then get a different result. Without a record of the setup, it is hard to tell whether the page changed or the test environment did.

A system baseline is a short record of the device and settings used during an audit. It helps you repeat a check and explain differences between results. TooLab's System Info and Browser Info can capture some useful details, but they do not replace recording accessibility settings and assistive technology yourself.

Record a baseline for your audit

1. Open System Info on the device you will use for the audit. Record the information it shows about the processor, graphics, screen, battery and network. Write down the device name or a label you choose, such as "office laptop A," separately.
2. Open Browser Info in the browser where you will test. Record the browser version, engine, permissions and any relevant supported features. Use the same browser profile for later comparisons, since extensions and saved site settings can differ by profile.
3. Record the display conditions. Note the screen resolution, operating-system scaling, browser zoom, orientation and whether an external display is connected. Include brightness or contrast settings if they are part of the test.
4. Write down the accessibility and input setup. Include the screen reader or magnifier and its version if used, text size, contrast theme, captions, keyboard layout, and whether you are using a mouse, touch screen, switch or other input device.
5. Save the date and the page or task you tested with the notes. If you repeat the audit after an update, compare the setup first, then compare the page behavior.

Keep the record concise. A short list of settings is more useful than a long inventory that does not explain what changed. Only record details relevant to the audit, and avoid including account names or other personal information in notes you will share.

What the baseline tells you

The device and browser details match

If the same device, browser version, display setup and accessibility settings are in place, a repeated test is easier to compare. That does not prove the results will be identical: a site update, browser extension, network change or background application can still affect behavior. The baseline gives you a starting point for finding the difference.

A browser or feature has changed

If Browser Info shows a different browser version, engine or feature support, treat the result as a different test environment. A page may behave differently even when you have not changed its code. Note the change, then repeat the test in the original browser if you need a direct comparison.

A device detail is missing or looks imprecise

Browsers expose only some device information. For example, a browser-reported RAM amount is a rounded hint, not an exact inventory. A missing value is not proof that the hardware is absent or broken. Use the operating system's settings for details that the browser cannot reliably report.

The same setup gives a different accessibility result

Check whether the site, operating system or assistive technology changed. Also confirm that browser zoom, text size, contrast, input method and permissions match your notes. A system baseline helps narrow down the cause, but it does not identify the cause automatically.

Make the setup repeatable

1. Use one device and browser profile. Avoid switching between a personal and work profile during a comparison. They can have different extensions, permissions and saved site data.
2. Record display scaling and zoom separately. On Windows 11, check Settings › System › Display for scale and display resolution. On macOS, check System Settings › Displays. Record browser zoom too, since it is separate from operating-system scaling. In most desktop browsers, Ctrl + 0 resets zoom on Windows and Command + 0 does so on macOS.
3. Note accessibility settings instead of resetting them. On Windows 11, relevant options are under Settings › Accessibility, including display, text size, contrast themes, magnifier and keyboard settings. On macOS, check System Settings › Accessibility for options such as VoiceOver, Zoom, Display, Pointer Control and Keyboard. Record the settings you actually use for the audit. Do not turn off an accommodation just to make a test look more typical.
4. Include mobile settings when auditing a phone. Record the model, operating-system version, browser and orientation. On Android, accessibility options are generally under Settings › Accessibility; on iPhone, use Settings › Accessibility. Menu names can vary by device and software version, so write down the option names shown on your phone.
5. Keep the testing conditions steady. Use the same input method and assistive technology for each comparison. If you change a setting, make one change at a time and add it to the baseline notes before testing again.

What browser checks cannot tell you

System Info and Browser Info describe details that the browser can access. They do not tell you whether a screen reader announces a button correctly, whether keyboard focus is easy to follow, or whether a person can complete a task with their preferred input method. Those require testing the page with the relevant assistive technology and interaction method.

Some device details are also unavailable or limited in a browser. The browser may report a rounded memory hint rather than exact RAM, and a feature list does not confirm that every feature works as expected in a particular page. Treat the tools as a way to document part of the environment, not as a pass or fail accessibility certification.

Keep one baseline with each audit run, and add a dated note whenever the browser, display, assistive technology or input setup changes.