PDF merger not working? Here's how to fix it
Most issues are small and fixable in seconds. Work through these in order.
1. The tool won't load
Reload the page or open it in a fresh tab. If an extension blocks scripts, use private (incognito) mode — the merger needs JavaScript, which is on by default in every modern browser.
2. A file won't upload
Check the format and size. Merge PDF accepts PDF up to 100 MB each. If a file is larger, split it first, or confirm the file really is a PDF (a renamed file from another type will be rejected).
3. The pages are in the wrong order
You merged before arranging. Drag and drop the files into the desired sequence first, preview, then download. This is the most common merge mistake.
4. Merging is slow or the browser lags
The merger runs locally, so memory matters. Close unused tabs, process fewer large files at once, and try again.
5. Nothing downloads
Check your browser's download location and pop-up/file settings. Many browsers quietly block automatic downloads from new sites.
Still stuck?
Try a different current browser (Chrome, Firefox, Safari, Edge). Because the tool runs locally, a fresh environment usually resolves remaining edge cases.
Verdict
Most Merge PDF problems are solved by a reload, reordering before merging, or a private window.