Accessibility
Short version: every calculator, guide and reference page on Tuning4U is built to work with a keyboard alone, with a screen reader, and at 200% zoom. We aim at WCAG 2.2 Level AA. This page says exactly what that means here, what we check, and the places we know still fall short.
Where we stand
Tuning4U aims to conform to the Web Content Accessibility Guidelines (WCAG) 2.2 at Level AA. The assessment is our own — this site has not been through a third-party audit, so treat it as a statement of intent backed by testing, not as a certification. Everything in Known gaps below is a real limitation we have found rather than a disclaimer.
What you can rely on
- Keyboard only. Every control is reachable and operable with Tab, Enter and Space. Nothing traps focus, nothing needs a mouse, and the focus ring is always visible at 3:1 against its background.
- Screen readers. Every field has a real label, every icon-only button has a name, and the answer a calculator produces is announced when it changes — you do not have to hunt for the number after moving a slider.
- Zoom and reflow. Pinch-zoom is never blocked. Pages reflow to a single column at 320 px wide (equivalent to 400% zoom on a desktop) without a horizontal scrollbar, apart from the wide tables noted below.
- Contrast. All body text clears 4.5:1 in both the dark and light themes, and the border of every control — inputs, unit toggles, ghost buttons, the fader handles — clears 3:1, so you can see where a control is, not just what it says.
- Motion. If your system asks for reduced motion, the animated rev counter on the home page settles to a static reading, the value rollers stop flicking, and scrolling stops being smoothed.
- No time limits. Nothing expires, times out or auto-advances. The only clock on the site is inside the two reaction games, where measuring time is the activity.
- No sign-up. There is no account to create, no CAPTCHA and no email verification step to get through before a tool works.
Keyboard shortcuts
- Tab Move through the page. The first stop is always Skip to content, which jumps past the header.
- / or Ctrl+K Open the search palette over every calculator, guide and cheat sheet. Cmd+K on a Mac.
- ↑ ↓ Move through search results; on a calculator, step the focused value up or down.
- ← → Move a fader bar when it has focus.
- Esc Close the search palette or the Tools menu and return focus to the button that opened it.
How this is tested
Two layers, because neither one is enough on its own.
- Automated, on every change.
scripts/check-a11y.jsruns in CI over every page on the site. It fails the build on an unlabelled field, an icon-only control with no name, a skipped heading level, a duplicate id, anaria-*attribute pointing at nothing, a data table with no header cells, a page that blocks zoom, a calculator whose result never announces, and any theme colour that drops below its contrast floor. - By hand, for the things a script cannot see. Tab order and focus return, screen-reader announcements, reflow at 320 px, and whether each of the three games is actually playable without a mouse. These are checked when the relevant code changes rather than continuously, which is why the list below exists.
An automated checker catches the failures that live in the markup. It cannot tell you whether a label makes sense, whether an announcement arrives at a useful moment, or whether a page is pleasant to use — so a clean run is a floor, not a pass mark.
Known gaps
These are the places we currently fall short of the bar above, and what we do about them.
| Where | The gap | What to do instead |
|---|---|---|
| Tune It | The fuel map is drawn on a canvas. It is fully keyboard-operable and each result is announced, but the shape of the curve — the thing the game is about — has no text equivalent. | The peak-power figure and the outcome of each pull are read out; the curve itself is not. |
| Reaction Time | The task is reacting to a light in under a fifth of a second. A screen-reader announcement cannot arrive fast enough to be part of that. | Staging, the result and the red-light warning are all announced. The green light itself is visual and audible only. |
| Home page | The rev counter animates continuously. It respects a reduced-motion setting, but there is no pause control on the page itself for people who have not set one. | Turn on reduced motion in your OS display settings and it holds a static reading. |
| Cheat sheets | These are dense reference tables designed to print on one page. On a narrow screen they scroll sideways inside their own box. | The page itself never scrolls sideways — only the table does — and every figure also exists in the calculator it came from. |
| Calculator diagrams | The tyre, wheel and cam diagrams carry a fixed description of what they show, not a live one that changes with your numbers. | Every value the diagram draws is also in the result tiles beside it, in text, and those announce as they change. |
Found something we missed?
Please tell us — this is the fastest way the list above gets shorter. Email admin@tuning4u.info or use the contact page, and if you can, include:
- The page address, and what you were trying to do.
- Your browser and any assistive technology you use, with versions if you know them.
- What happened instead of what you expected.
We read every message and aim to reply within five working days. If something is stopping you using a calculator, say so and it goes to the front of the queue — a tool nobody can operate is a broken tool, not a low-priority ticket.
Technical notes
The site is static HTML, CSS and JavaScript with no framework and no build step. It relies on JavaScript for the calculators themselves; the surrounding content — guides, the glossary, cheat sheets and the OBD-II code pages — is plain markup and reads fine without it.
Conformance is measured against WCAG 2.2 Level AA using a mix of automated checks and manual testing, as described above. The admin dashboard at /admin/ is a private, password-protected page and is not part of the public site.
See also our privacy & cookies page and our terms & disclaimer.