Live Scroll Position & Page Size
See your live scroll position, page dimensions and scroll percentage. Updates as you scroll.
How to use this tool
- Open this page — it runs instantly in your browser, no signup or install.
- Allow any permission prompt if asked; everything stays on your device.
- Use the on-screen controls — results update live.
See your live scroll position, page dimensions and scroll percentage. Updates as you scroll.
How it works
The Live Scroll Position tracker displays your current vertical and horizontal scroll offset in pixels, the total page dimensions, and your scroll progress as a percentage. All values update instantly as you scroll the page.
Scroll offset (scrollTop / scrollLeft) tells you how many pixels the page has scrolled from the top or left edge. Page height is the total document height including the off-screen portion. Scroll percentage is your current offset divided by the maximum scrollable distance, expressed as a value from 0% (top) to 100% (bottom).
Web developers use this to debug scroll-triggered animations, verify scroll-progress indicators, and check that anchor links land at the correct vertical position. Testers use it to document reproduction steps that depend on scroll depth.
No data leaves your browser. All measurements are read from standard browser DOM properties.
Worked example
Verify a scroll-progress bar reaches 100% at the page bottom
- Open the Scroll Position tool on a long page.
- Note the scroll percentage at the top (should be 0%).
- Scroll slowly to the bottom of the page.
- Confirm the percentage displayed reaches 100% when you can scroll no further.
Confirmed or identified a bug in the page's scroll-progress calculation by comparing it to the ground-truth percentage shown here.
Common mistakes to avoid
- Confusing viewport height with page height — viewport height is the browser window size, while page height is the full scrollable content length.
- Checking scroll percentage on a page shorter than the viewport — there is nothing to scroll so the percentage stays meaningless.
- Using viewport-relative scroll values from this tool as absolute page offsets in JavaScript without accounting for the scroll offset already applied.
Key terms
- scrollTop
- The number of pixels the document has been scrolled vertically from the top; 0 means the page is at the very top.
- Document height
- The total height of the full page content, including parts not currently visible in the viewport.
- Scroll percentage
- The ratio of current scroll offset to the maximum scrollable distance, expressed as a percentage from 0% to 100%.
Frequently asked questions
- What is scrollHeight?
- scrollHeight is the total height of the page including content outside the viewport. Subtract the viewport height to get the scrollable distance.
- How is scroll percentage calculated?
- scrollY / (scrollHeight - innerHeight) × 100. At the very top it is 0%, at the bottom 100%.