How do I merge PDF files for free?

Add PDFs or other supported files (images, DOCX, XLSX, TXT, ODT). Non-PDFs convert to PDF in the browser first. Drag cards to set order, check the total page count, then click Merge. Download uses pdf-lib and PDF.js locally.

Can I see a preview of each PDF?

Yes. Each file shows a thumbnail of the first page rendered with PDF.js. Use the zoom icon for a larger preview.

Are my PDFs uploaded?

No. Merging runs in your browser only.

What is the file size limit?

Up to 100MB per file. Large merges may need a desktop browser.

Password-protected or damaged PDFs, failed conversions, or encrypted Office files may fail. Unlock or re-save files, or remove the problem item.

Merge PDF

Combine PDFs and other files (images, Word, Excel, text, ODT) into one PDF — first-page previews, drag-and-drop order, and total page count. Non-PDF files are converted in your browser first, same engine as Convert to PDF.

Reorder by dragging a card, or drop on a card or in the gaps between cards. Drop PDFs or supported files into a gap to insert. Accepted: PDF, JPEG, PNG, WebP, GIF, DOCX, XLSX, XLS, TXT, ODT (legacy DOC/PPT skipped; PPT — export as images first).

Drop files here or use Add files below. PDFs merge as-is; other types convert to PDF per file. Each file can have many pages — all pages follow your card order.

Options for converted files

These settings apply when adding or refreshing Word, images, text, etc. Changing an option re-builds previews for non-PDF items already in the list.

Images

A4 Letter Auto-fit

Word (DOCX)

Page breaks before major headings No extra breaks

Excel (XLSX / XLS)

Each workbook becomes one PDF with all sheets (same as “all sheets in one PDF” on Convert to PDF). Legacy XLS may fail — save as XLSX if needed.

Plain text (TXT)

Font size (11pt)

Margins

Line spacing

Filename as header

Method Create bookmarks (best effort)

Merged PDF ready

Frequently asked questions

How do previews work?

PDF.js renders the first page of each PDF as a thumbnail. Your full PDFs — every page — are merged with pdf-lib.

Can I reorder files?

Drag a card or drop it in the narrow blue highlights between files. You can also drag new PDFs from your computer into a gap to insert them in the middle. Left-to-right order is merge order.

What does “Create bookmarks” do?

pdf-lib has limited outline support in the browser. The checkbox sets document metadata when possible; rely on page order for structure. Desktop tools add richer bookmarks.

Can I merge Word or Excel, not only PDF?

Yes. DOCX, XLSX, XLS, TXT, ODT, and common images are converted to PDF in the browser (same approach as Convert to PDF), then combined in your chosen order. Legacy .DOC and PowerPoint are not converted here.

Merge failed — why?

Encrypted PDFs, bad conversions, or damaged files may fail. Try unlocking in Acrobat, re-saving as PDF or XLSX, or removing the problem file.

Is data uploaded?

No. All processing is in your browser.