How can StackBlitz WebContainers efficiently paginate large datasets fetched from external APIs without exceeding browser memory limits?

Recommended approach

Use cursor-based pagination at the API level and keep only the current page plus the cursor in browser memory. Do not accumulate pages in a global array. Cursor pagination avoids offset scans and stays stable when rows are inserted or deleted; limit/offset is acceptable only for small, static datasets where previous pages are discarded immediately.

Confirmed behavior and assumptions

• Browser tab memory, not WebContainer internals, bounds retained data. SharedArrayBuffer or cross-origin isolation does not change pagination logic.
• StackBlitz hot reloads and container restarts do not reliably preserve Node module state, so in-memory caches across reloads are unsafe.
• Memory grows with retained row count and object graph size, not with the pagination method itself.
• No universal safe page size exists; it depends on average serialized row size and device.

Implementation steps

1. Request pages with limit and cursor (or next_cursor) from the external API. Fetch only the next page when the user navigates forward.
2. Store the current page data and cursor in a small UI state object. Replace, do not append, previous page data unless you explicitly need history.
3. Persist the cursor and page index in the URL search params or sessionStorage so a preview reload refetches only the current page.
4. Virtualize the visible list so only rendered rows are kept in the DOM; discard off-screen rows if possible.
5. Start with a conservative page size, such as 50–100 records, then measure heap growth before increasing it.

// Example state shape
const state = {
  page: [],
  cursor: null,
  pageIndex: 0,
};

// Persist on navigation
const params = new URLSearchParams(window.location.search);
params.set('cursor', state.cursor);
params.set('page', state.pageIndex);
window.history.replaceState(null, '', `${location.pathname}?${params}`);

Verification

• Open Chrome DevTools Memory, take a heap snapshot, page through several results, and take another snapshot. Retained memory should return to approximately the current-page baseline.
• Watch Chrome Task Manager or about:processes while increasing page size; stop at the largest size that remains stable and responsive.
• Reload the StackBlitz preview and confirm the persisted cursor causes one refetch of the current page, not a full dataset refetch.

Missing diagnostic

What is the average serialized size of one API row, and do you need to retain previous pages for backward navigation? This determines whether 50, 100, or a larger page size is safe for your target devices.

Assumption: a modern Chromium-based browser and a standard StackBlitz WebContainer tab. Page-size guidance is conservative and should be verified on the lowest-memory target device.