Progressbar
A progressbar shows how much of a timed task is done. People can read it but do not control it directly.
A real example
While a 2.4 GB file uploads, the bar announces “Upload, 68 percent” and updates only when useful. It shows an unknown amount while the server checks the file. Cancel remains a separate button.
Main parts
- 01Task label
- 02Track and fill
- 03Current value
Use it when
Show a number when the total work is known. If it is unknown, label that state and explain what is happening now.
Do not use it when
Do not make a progressbar focusable or adjustable. Use a slider when the person controls the value.
Name used in code
role=progressbar with aria-valuemin/max/now and accessible name Before you ship
Before release, check the page structure, keyboard access, visible focus, contrast, and zoom. Also check loading, empty, error, success, cancel, and reduced-motion states.
Outcome: Use Progressbar to solve this user need without losing the current context. User context: While a 2.4 GB file uploads, the bar announces “Upload, 68 percent” and updates only when useful. It shows an unknown amount while the server checks the file. Cancel remains a separate button. Recommended pattern: Progressbar. Why it fits: Show a number when the total work is known. If it is unknown, label that state and explain what is happening now. Do not use it when: Do not make a progressbar focusable or adjustable. Use a slider when the person controls the value. Product requirements: Define the default, loading, empty, error, success, and recovery states. Keep user input. Give clear feedback after every action. Accessibility and resilience: Use semantic HTML, full keyboard access, and visible focus. Make the layout work when zoomed and support reduced motion. Follow the project’s current rules. Do not add a new UI library unless the project already uses it. Acceptance criteria: The main task works with keyboard only and at 320px width. Focus and status changes are announced. Check loading, failure, retry, cancel, and reduced-motion paths. Evidence and limits (evidence boundary): The standard covers only the listed scope. It does not choose the visual style, product decision, or Vibulary example. Unknowns to confirm: Product wording, data source, analytics events, supported devices and languages, and platform limits.
Check this request
Review the current use of Progressbar. Definition: A progressbar shows how much of a timed task is done. People can read it but do not control it directly. Release checks: Before release, check the page structure, keyboard access, visible focus, contrast, and zoom. Also check loading, empty, error, success, cancel, and reduced-motion states. Before changing code, report the evidence you found, gaps, severity, and the smallest safe fix.