How to Merge PDF Files Online
Merging PDF files is one of the most common document tasks in both professional and personal life. You might need to combine a cover letter with a resume before sending a job application. You might be assembling a report from sections written by different people. You might have scanned a multi-page document one page at a time and now need to join everything into a single file. Whatever the reason, merging PDFs is straightforward when you have the right tool.
- Combine a cover letter and resume into one PDF before applying for a job
- Assemble a report or proposal from multiple chapter files
- Join scanned pages into a single document
- Merge invoices or receipts into one file for accounting or expense reports
- Combine PDF handouts into one file before sharing with a class or team
All of this can be done in your browser in under a minute, with no software to install and no account required.
How to merge PDF files online - step by step
- Open the Dockitt Merge PDF tool in your browser.
- Click 'Choose PDFs' or drag and drop your files into the upload area. You can select multiple files at once by holding Ctrl on Windows or Cmd on Mac.
- Check the order of the files in the list. The final document will follow the order shown.
- If the order is wrong, rearrange the files by dragging them into the correct sequence.
- Click 'Merge PDF' and wait a few seconds while the tool combines your files.
- Once complete, click 'Download' to save the merged PDF to your device.
- Open the downloaded file to confirm all pages are present and in the right order.
How merging PDFs works
When you merge PDF files, the tool joins the pages from each document in sequence to create a single new PDF. The content of each file is preserved exactly as it was. Text remains selectable and searchable, images stay at their original quality, fonts are embedded, and hyperlinks continue to work.
- Page content is not re-rendered: The original page data is copied directly into the merged file. There is no re-compression or quality loss.
- Bookmarks and metadata: Some PDF merge tools carry over bookmarks from the original files. Simple online tools typically do not, so if you need a bookmarked table of contents in the merged file, you may need a desktop application.
- File size of the merged PDF: The merged file will be roughly the sum of the sizes of the individual files. If the result is too large, run it through the Compress PDF tool afterwards.
- Password-protected files: A file that requires a password to open cannot be merged until it is unlocked. Use the Unlock PDF tool first.
Getting the page order right before merging
The order of pages in the merged PDF depends entirely on the order in which you arrange the files before clicking Merge. Getting this right before merging saves you from having to redo the process.
- Select files in order: On most operating systems, you can select files in a specific order by clicking them one at a time while holding Ctrl on Windows or Cmd on Mac. The files will be added to the upload list in the order you clicked them.
- Drag to reorder: After uploading, most merge tools let you drag files up or down to change the order. Check the list carefully before merging.
- Name files with numbers: If you regularly merge the same set of files, naming them with a numeric prefix such as 01-intro.pdf, 02-chapter.pdf, 03-conclusion.pdf makes it easy to select them in the right order every time.
- Fix order after merging: If the pages end up in the wrong order after merging, use the Reorder PDF Pages tool to drag individual pages into the correct sequence without having to merge again.
Common use cases for merging PDFs
Understanding when and why to merge PDFs helps you decide whether it is the right approach for your situation.
- Job applications: Employers often ask for a single PDF containing your resume, cover letter, and any supporting documents such as certificates or references. Merging these into one file is cleaner than sending multiple attachments.
- Legal and financial documents: Contracts, agreements, and financial statements are often split across multiple files. Merging them into a single document makes signing, archiving, and sharing simpler.
- Scanned documents: When scanning a multi-page document on a flatbed scanner that produces one file per page, merging is the final step that creates a usable document.
- Reports and presentations: Team members working on different sections of a document often produce separate files. Merging combines their work into the final deliverable.
- Invoices and receipts: Accountants and finance teams often need to submit all invoices for a period as a single PDF. Merging them is faster than emailing them individually.
Merging PDFs on different devices
You can merge PDFs from any device with a browser. Here is what to expect on each platform.
- Desktop and laptop: The easiest experience. Drag and drop files directly into the tool, reorder them in the list, and download the result. Chrome and Firefox work best.
- iPhone and iPad: Open the tool in Safari or Chrome. Tap the upload area to select files from your Files app, iCloud Drive, or other connected storage. The process works the same as on desktop.
- Android: Open the tool in Chrome. Tap to select files from your device storage or Google Drive. Merging and downloading works identically to desktop.
- Chromebook: Use the Chrome browser. Files can be selected from local storage or Google Drive. The tool runs entirely in the browser and works well on ChromeOS.
What to do after merging
Once you have your merged PDF, there are a few things worth doing before sharing or submitting it.
- Check the page count: Open the file and confirm the total number of pages matches what you expect. If any pages are missing, one of the source files may not have uploaded correctly.
- Check the page order: Scroll through quickly to make sure the pages flow in the right sequence.
- Compress if needed: If the merged file is larger than you need, run it through the Compress PDF tool to reduce the size.
- Protect if needed: If the document contains sensitive information, use the Protect PDF tool to add a password before sharing.
- Split if needed: If you merged more than you intended, use the Split PDF tool to extract the pages you actually need.
Common problems
The merged PDF is missing some pages.
Make sure all files uploaded correctly before merging. If a file shows an error during upload, remove it and re-add it. Also check that none of the source files are corrupted by opening them individually before merging.
The page order in the merged file is wrong.
Reorder the files before clicking Merge. The final document follows the order shown in the upload list. If you have already merged and the order is wrong, use the Reorder PDF Pages tool to fix the sequence without merging again.
One of the PDFs is password protected and will not merge.
Password-protected PDFs cannot be merged until they are unlocked. Use the Dockitt Unlock PDF tool to remove the password, then try merging again.
The merged file is very large.
The merged PDF will be roughly the combined size of all input files. Use the Dockitt Compress PDF tool after merging to reduce the file size without losing quality.
The fonts or layout look different in the merged file.
This should not happen with a proper PDF merge, as the page content is copied directly without re-rendering. If you see layout differences, the source files may have been created with non-embedded fonts. Try opening each source file individually to confirm they display correctly before merging.
Related tools
FAQ
How many PDF files can I merge at once?
There is no hard limit on the number of files. You can merge two files or twenty. Very large batches with many high-resolution files may take longer to process, but there is no enforced maximum.
Will the formatting and fonts be preserved after merging?
Yes. Merging PDFs does not alter the content of individual files. Text, images, fonts, and layout are all preserved exactly as they are in the original files. The merge operation joins pages together without re-rendering or re-compressing anything.
Can I merge a scanned PDF with a regular PDF?
Yes. Scanned PDFs and text-based PDFs can be merged together without any issues. The result will be a single PDF containing all pages from both files, regardless of how each was originally created.
Is it safe to merge PDFs online?
Yes. Dockitt's Merge PDF tool processes files entirely in your browser using PDF.js and pdf-lib. Your files are never uploaded to a server. They stay on your device throughout the entire process.
Can I merge PDF files on my phone?
Yes. Dockitt works on mobile browsers on both iPhone and Android. You can upload files from your device storage, merge them, and download the result directly to your phone.
Can I merge PDF files that have different page sizes?
Yes. PDFs with different page sizes such as A4 and Letter can be merged together. Each page retains its original dimensions in the merged file. The page sizes are not standardised or resized during the merge.
Does merging PDFs remove bookmarks or hyperlinks?
Hyperlinks within pages are preserved. Bookmarks, which are the clickable navigation entries in the PDF sidebar, may not be carried over by simple online merge tools. If you need to preserve or create bookmarks in the merged file, a desktop application such as Adobe Acrobat or PDF-XChange Editor gives you more control.
What is the difference between merging and combining PDFs?
Merging and combining mean the same thing in the context of PDF files. Both refer to joining multiple PDF documents into a single file. The terms are used interchangeably.
Try it now
Ready to combine your PDF files? Use the free Dockitt merger below.