How do you merge, split and compress PDF files?
Merge PDFs, split out page ranges and shrink oversized files in about five minutes with free PDF24 Creator or browser tools.
Short answer
On Windows, install the free PDF24 Creator and use the "Merge PDF files", "Split PDF files" and "Compress PDF" tiles on the start screen. Drag your files into the window, fix the order, press the matching button and save the result. For compression, 150 DPI with 75% image quality is enough for most official submissions. All three jobs take roughly five minutes.
What you need
Step by step
Line the files up in one folder
Copy every PDF you plan to merge into a single folder and prefix the names with 01-, 02-, 03-. Most tools sort by file name, so numbering keeps the page order from scrambling in the merged document. For ten files this prep takes two to three minutes.
Install PDF24 Creator
Download the PDF24 Creator installer from pdf24.org and pick your language during setup. The program does all the work locally, so your documents are never uploaded to a server. Download and installation take three to five minutes on a normal connection.
Merge the PDFs
Click the "Merge PDF files" tile on the start screen and drag your files into the window. If the order is wrong, grab a file with the mouse and move it up or down, then press the "Merge" button at the bottom. Use "Save" to write the result to your desktop as merged.pdf.
Split the document into pages
Open the "Split PDF files" tool from the start screen and add your file. Type a range such as 3-7 under "Split by page ranges", or tick "Split after each page" if you want every page as a separate file. Pressing "Split" downloads the results as a ZIP archive.
Compress the file
Add the file to the "Compress PDF" tool, set "DPI" to 150 and "Image quality" to 75%, then press "Compress". 150 DPI stays readable on screen and prints fine. A 20 MB scanned document usually drops to 2-4 MB with these settings.
Check the size and the pages
Right-click the saved file and read the "Size" line in the "Properties" window. If it is still above your limit, drop the DPI to 100 and compress again. Then open the file and zoom in on the first page, the last page and any signature or stamp areas to confirm they are legible.
Use a browser tool instead
For a one-off job, use ilovepdf.com or Adobe's "Merge PDF" page: drag the file in, press the button, download the result. Free tiers cap the number of daily files and the maximum size. Do not upload personal documents such as ID cards, medical reports or contracts to these sites.
Finish on a Mac with Preview
On macOS, open the file in Preview, choose "View > Thumbnails" and drag the second PDF into the sidebar to merge them. To shrink the size, go to "File > Export" and pick "Reduce File Size" from the "Quartz Filter" menu before saving.
Tips
Watch out
Compression cannot be undone: below 100 DPI, small type, stamps and signatures blur and the receiving office may reject the document. Never save over the original. Add "-compressed" to the file name to create a new copy, and zoom in to check legibility before you send it.
Frequently asked questions
+Does compression ruin the text?
At 150 DPI and 75% quality, text stays readable. At 72-100 DPI, small type and stamps blur, so never go below 150 DPI for official submissions.
+Can I compress a digitally signed PDF?
No. Merging, splitting or compressing changes the file contents, which invalidates the electronic signature. Send digitally signed documents exactly as you received them.
+Do free tools have file limits?
The PDF24 Creator desktop version has no page or size limit. Web tools like iLovePDF and Adobe cap daily operations and file size on their free plans.
+Why is the page order wrong after merging?
The tool sorts files by name. Prefix the file names with 01-, 02- and so on, or drag the files into the correct order inside the merge window.
+Why won't the file size drop at all?
If the document is already text-based there are no images to compress, so you only gain 5-10%. When such a file is large, the bulk comes from scans, and rescanning the pages at a lower DPI works better.
Sources and verification
Last verified: September 15, 2026. tell us.
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