My phone browser freezes when I merge large scanned PDFs. What can I do?
Merge fewer files per round and then merge the results, and close other tabs before you start. [[merge-pdf]] holds every file you added, plus the new file it builds, in your device's memory at the same time, and phones have far less memory than computers. If it still freezes, a computer is the reliable fix.
Why scans in particular
A scanned page is a whole picture, not text. A file of 120 scanned pages can be far heavier than a 500-page text document. So page count alone tells you little: the tool accepts up to 500 pages and 100 MB per file, but a phone can struggle well before those limits when the files are heavy images.
And during a merge the files are not in memory just once. Merge PDFs keeps each file open from the moment you add it until you press merge, then builds the new file alongside them. So at the moment of merging, two big files take up noticeably more memory than their size on disk suggests.
Steps that usually work
- Close other tabs and apps, since they all share the same memory.
- Merge only two or three files per round, then merge the round results together in a final round.
- Press 'Reset' between rounds so the list lets go of the previous round's files.
- If the browser freezes even with two files, move the job to a computer, even just this once.
Two scanned files of 120 and 150 pages. The tool accepts them, since 270 pages is well under the 2000 ceiling.
But accepted means the tested limits were not exceeded, not that your particular phone has enough memory for those two files.
Does splitting help?
Sometimes. If you only need part of a huge scan, pull out the pages you need first in Split PDF, then merge that smaller part. If you need the whole file in the result, splitting and re-merging does not reduce what the device must hold in the end, and a computer is the better place.
For next time: if you do the scanning yourself, a sensible resolution produces much lighter files than the highest setting the scanner offers, and ordinary office paperwork stays perfectly readable.
Common questions
Does a frozen browser mean my files are damaged?
No. The tool never changes your original files, so they are exactly as they were. Reload the page and try smaller batches.
Would merging on a server be faster?
It might, but it means sending your documents to someone else's machine. This tool keeps files on your device, and the trade-off is relying on its memory.
How do I know the merge is still running?
The progress bar moves as each file is copied. If it stalls for a long time and the page stops responding, try again with fewer files.