My tools

PDF merger

Put several PDFs in the order you want, then preview and download one merged file — right here.

Waiting for files

Add PDFs in the order you want them combined.

Drop several PDFs on this card, paste with ⌘V / Ctrl+V, or choose files. Merging starts on its own — there is no Merge button.

PDF only · up to 20 files · 50 MB each · 100 MB and 2,000 pages in total.

Files stay in this tab: nothing is uploaded, stored or logged, and the page sends no network request.

No PDF at hand? Load two local sample files (3 pages together) and try the whole flow.

Merged PDF preview

merged.pdf

If the preview stays blank, open it in a new tab or download the file.

Open in new tab

How to use it

  1. Drop PDFs on the card, paste with ⌘V / Ctrl+V, or press “Choose PDFs”. Files are appended in the order you add them, and merging starts immediately — there is no Merge button and nothing is uploaded.
  2. Check the order in the list: row 1 supplies the first pages of the output. Drag the grip, or use the up/down buttons; each row shows its page count, size and the page range it will occupy (for example pp. 2–5).
  3. The status turns green and says “Merged · N pages” when the file is ready. Press “Preview” to check the whole document in your browser, or “Download PDF” to save merged.pdf. A change in the list builds the file again automatically; preview and download stay disabled until the new file matches the order you see.

Example

Two files, in this order

Contract cover.pdf — 1 page, 210 KB
Body.pdf — 4 pages, 1.0 MB

merged.pdf

merged.pdf — 5 pages
Order: cover, then body
Body pages are pp. 2–5

Page ranges are cumulative: the first file starts at page 1, and each following file starts after the pages before it. The output is a new file; neither source is modified.

Rules, limits and known issues

  • Nothing is uploaded: files are read with the File API and merged in this tab. The page sends no network request, writes nothing to storage, and keeps no history — a reload starts from an empty list.
  • Page content is copied, not re-encoded. Images and fonts keep their original compression, so the merged file is usually about the size of the inputs combined; this is not a compression tool.
  • Password-protected PDFs are rejected; there is no “ignore encryption” option. Open the file with its password and save an unprotected copy first.
  • Form fields are not carried over. Page appearances may survive, but the output is not a fillable form; flatten the form in the source if it must look exactly as it does now.
  • Bookmarks/outlines, attachments and document metadata (title, author, subject) are not copied. The output gets a localised title and a YKit Creator/Producer tag. Links on the page usually survive, but links that point to named destinations or bookmarks may stop working.
  • Any merge changes the bytes, so digital signatures are no longer valid. PDF/A, PDF/X and other conformance markers are not preserved either.
  • Preview uses your browser’s built-in PDF viewer, not page thumbnails or a rendered copy. Inline display and mobile behaviour depend on the browser; if the preview area stays blank, open the file in a new tab or download it. Preview never changes the file.
  • Limits: 20 files, 50 MB per file, 100 MB and 2,000 pages in total. A file that would cross a limit is rejected on its own; files already in the list are kept. Jobs over 40 MB or 500 pages show a “may take a few seconds” hint.
  • Merging runs on the main thread. Large jobs can occupy the tab for several seconds and make other interactions feel slow; the status shows reading and merging progress while it works.
  • Encrypted PDFs, damaged files, 0-byte files and files without a %PDF- header are rejected with a specific message; they do not silently produce a partial download.

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