The table says 2,431 rows. You export it and get 50. Nothing errored.
This is almost always virtualisation, and it is worth ten minutes of your time to understand, because it is the one failure mode where a tool that says nothing is worse than a tool that refuses.
Rendering thousands of rows is slow, so grids render a window: the rows you can see plus a few above and below. As you scroll, rows outside that window are removed from the page and new ones are created. react-window, react-virtualized, TanStack Virtual and AG Grid's own row virtualisation all work this way, and so does every infinite-scroll list.
So at any moment the page contains fifty rows. Not fifty visible out of 2,431 present, fifty present. Copy, select-all, an extension, a console script: they all read the same page, and they all get fifty, because that is what is there.
Paste this into the DevTools console:
const g = document.querySelector('[role="grid"],[role="treegrid"],table');
console.log({
claims: g.getAttribute('aria-rowcount'),
inPage: g.querySelectorAll('[role="row"],tr').length
});The aria-rowcount attribute is the grid telling assistive technology how many rows exist in total. When that number is much larger than the number of rows in the page, you have your answer. Not every grid sets it, but the well-behaved ones do.
1. Find the page's own export. A Download CSV or Export to Excel button asks the server and returns every row. This is the only route that is both complete and reliable, and it is worth looking for properly before trying anything else.
2. Turn up the page size. Many grids have a rows-per-page control at the bottom offering 25, 50, 100 or All. Switching to the largest value often turns off virtualisation entirely, and then a normal copy or extract gets everything.
3. Check for a print view or a URL parameter. Plenty of internal tools accept a limit or per-page value in the query string, or have a printable version that renders the whole set as a plain table. Look at what the pagination links put in the URL.
4. Scroll the whole grid, then extract. This works only on grids that keep rows once they have been rendered, which is a minority. On a true virtualiser the rows behind you are already gone, so scrolling gains you nothing. Try it, then re-check the count with the snippet above before you trust the result.
5. Go to the API. Open the Network tab, filter to Fetch/XHR, page the grid so it refetches, and read the JSON. Usually you can request a larger page size directly. Right-click the request, Copy as cURL, and it carries your session with it.
A browser extension sees the same DOM you do. There is no privileged path to rows that were never rendered. An extension could scroll the grid for you, but on a real virtualiser that discards what it scrolls past, and on an infinite-scroll list it can take minutes and still miss rows that load late.
What a tool can do is tell you. GridPick compares the number of rows actually in the page against what the grid claims, and says so before you export, instead of handing you 50 rows out of 2,431 and letting you find out later. Most tools say nothing, which is how a partial export ends up in a report.
Two other things produce the same symptom and have different fixes:
The console snippet above tells the three apart in one line, so run it first.
GridPick does this for you. It reads real tables and div-based grids, expands merged cells, warns you when a grid is only half loaded, and exports to Excel, CSV, JSON or Markdown. The free version has no row limit; Pro is a one-time payment.