How to Merge PDF Files Online

When to merge PDF files

Merging PDFs is useful whenever you need to combine related documents into a single file. Common scenarios include combining monthly receipts and invoices into a single archive, assembling a project report from multiple sections contributed by different team members, creating a portfolio from individual work samples, and combining scanned pages into a single document.

A merged PDF is easier to share, store, and navigate than multiple separate files. It also ensures that the documents are read in the intended order.

Preparing your files before merging

Before merging, review each file to make sure it is complete and correct. Check that all pages are present, that the page orientation is consistent, and that the file names reflect the intended order. Renaming files with a numeric prefix (01-report.pdf, 02-appendix.pdf) helps you confirm the merge order before you start.

If any of the source files are very large, consider compressing them before merging. This reduces the size of the final merged document and makes the merge process faster.

Step-by-step: merging PDFs

1. Open a PDF merge tool like PDFKit at pdf.explorme.com.

2. Select or upload the PDF files you want to merge.

3. Arrange the files in the desired order. Most tools let you drag and drop to reorder.

4. If you need to merge specific pages rather than entire files, look for a tool that supports page-level selection.

5. Start the merge process. The tool combines the files into a single PDF.

6. Download the merged PDF and review it to confirm the page order and content.

7. If the merged file is large, compress it using a PDF compression tool.

Ordering and rearranging pages

The order of the files in the merge tool determines the order of the pages in the output. Most tools display a list or thumbnail view that lets you drag files to reorder them. Take a moment to confirm the order before starting the merge.

Some tools also let you rearrange individual pages within the merged document. This is useful when you need to insert a page from one document between pages of another, or when you need to move a cover page to the beginning.

Handling different page sizes

When merging PDFs with different page sizes (for example, A4 and Letter), the merged document will contain pages of mixed sizes. This is usually fine for digital viewing, but it can cause issues if the document is printed. If consistent page size is important, consider resizing the pages before merging or using a tool that normalizes page sizes during the merge.

Mixed orientations (portrait and landscape) are also handled correctly by most PDF viewers, but check the merged document to confirm that rotated pages display correctly.

Merging and compressing in one step

Some tools combine merging and compression into a single operation. This is convenient when the merged document would be too large for its intended use. If your tool supports this, enable compression during the merge to produce a smaller output file.

If your merge tool does not support compression, you can compress the merged file afterward. This is a two-step process but gives you more control over the compression level.