Merge PDFs in order, the right order on the first try

By the getPDF team · Published 11 October 2026

The short answer

Number your file names (01, 02 and so on up to 10, or 001 for 100 files or more), drag the folder onto Merge PDF below, check the list, and press Merge: the files go in exactly as listed, and a dropped folder is listed in name order with numbers counted as numbers. To move a file, use its Up and Down buttons. There is no file count cap, and nothing is uploaded.

Try it here, nothing is uploaded

Drop PDFs to merge

PDF · any number of files · any size

Why does 10 come before 2?

Most file lists sort names letter by letter. Compared letter by letter, 10-receipt.pdf comes before 2-lease.pdf, because the first character, 1, comes before 2. Put 12 files through such a sort and you get 1, 10, 11, 12, 2, 3 and so on.

The same 12 files sorted letter by letter, and sorted with numbers counted as numbers. Padding the names with a 0 gives the right order in every program.

Two ways out, and the first is the one that never fails:

Pad the numbers. 01 to 12 for up to 99 files, 001 for up to 999. Every program, every operating system and every website sorts padded names correctly.
Drag the folder onto Merge PDF. A dropped folder is listed in name order with numbers counted as numbers, so 2-lease.pdf comes before 10-receipt.pdf even without padding. Subfolders are walked in the same order, each one’s files in turn.

How do I merge files in a set order, step by step?

Name the files with a number at the front, padded: 01-cover.pdf, 02-lease.pdf, and so on. Put them in 1 folder.
Drag the folder onto Merge PDF above. Files that are not PDFs are left out, and a line says how many.
Read the list from the top. Each file shows its name, page count and size. The page count is a quick check: the 1-page cover should not say 14 pages.
Fix any file with its Up and Down buttons, or take it out with Remove.
Keep Bookmark per file on. The result gets 1 bookmark per file, named after it, with that file’s own bookmarks under it.
Press Merge, then Download PDF. The file is named after the first file with -merged added.
Open the bookmarks panel in your viewer. The bookmarks read top to bottom in the order the files went in, so a wrong order shows at a glance.

A folder picked with the or a whole folder button is sorted the same way as a dropped one. Files picked one by one in the file chooser, or pasted, arrive in the order your browser hands them over, which is not always name order; step 3 matters most then.

Moving 1 late file to position 3 of 20

The list has no drag and drop and no sort buttons; each file has Up and Down. Moving file 20 to position 3 is 17 presses of Up. Two quicker ways:

Add files in the order you want them. New files always go to the end of the list. Drop files 1 and 2, then the late addition, then the other 17.
Rename and drop again. Name the late file 02b-addendum.pdf, or renumber, press Start over if needed, and drop the folder.

Reordering pages, not files

Merge orders whole files; each file’s pages stay in their own order. If page 7 of the lease belongs after the payslip, merge first, then open the result in Organise PDF, which lists every page with Up, Down, Turn and Remove, and Reverse the order for a stack that was scanned backwards. For many pages, the editor’s page rail lets you drag thumbnails instead; the organising pillar compares the 2.

Organise pagesReorder, rotate, delete, insert. Free, runs on your device.

Organise keeps the bookmarks, the per-file ones included, and points them at the pages’ new places, so reordering after the merge costs you nothing.

The honest part: limits on files and order

No file count cap here. In our test run, 100 single-page invoices (2.1 MB in all) merged in under 1 second, with 100 bookmarks. Online mergers that upload your files cap the free tier instead; checked on 11 October 2026, iLovePDF’s free merge takes up to 25 files and 100 MB (compared), and Sejda’s free website merge stops at 50 pages or 50 MB, with 3 tasks an hour (compared).
The real ceiling is memory. The files and the merged result are held in your browser while it works. 100 typed files are nothing; 100 scans of 10 MB each are 1 GB of input, which a laptop may manage and a phone may not. The tool says when a file is too big for the browser to hold. Compress the scans as a batch first, which also keeps the result sendable; see a merged PDF that is too big.
Mixed page sizes stay mixed. The merge keeps each page’s size; merging different page sizes covers making them match.
The order is files, then pages. Merge cannot slot page 7 of one file between pages of another in the same pass; that is Organise or the editor afterwards. The files’ own bookmarks do come along, nested under each file’s entry, and their links between pages keep working.

Everything runs on your device: the files are read, merged and saved in your browser, and nothing is uploaded.

Questions

In what order does Merge PDF combine the files?

In the order of the file list, top to bottom, and each file's pages in their own order. The options panel says it: Order, as listed. Move a file with its Up and Down buttons before you press Merge.

Why does file 10 come before file 2?

Because many programs sort names letter by letter, and the character 1 comes before 2. Name the files 01, 02 and so on up to 10 and every program sorts them right. When you drag a folder onto Merge PDF or pick it with the folder button, it counts numbers as numbers, so 2 comes before 10 either way.

Can I drag files into a new order?

Not in the file list: it has Up and Down buttons for each file. For a long list, it is quicker to number the file names and drop the folder, or to add the files in the order you want, because new files go to the end of the list.

Is there a limit on how many files I can merge?

No file count cap. The limit is your device's memory, because the files and the result are held in your browser while it works. In our test run, 100 single-page invoices merged in under 1 second.

How do I check the order after merging?

Open the bookmarks panel in your PDF viewer. The merge adds 1 bookmark per file, named after the file and pointing at its first page, so the list of bookmarks is the order the files went in.