PDF Optimizer
Merge PDFs into one file and trim their size.
About This Tool
This tool joins PDF files into one and cleans them up. It runs on your own device, so it is safe for private documents.
- Merge up to 100 PDFs into a single file.
- Optimize each file to remove extra data and repack it.
- Do both in one step.
- See the size before and after for every file.
How to Use This Tool
- Click the upload area or drag your PDF files onto it.
- Tick Optimize, Merge All, or both.
- If you tick Merge All, set the order with Move up and Move down.
- Press Process PDFs.
- Download each file, or all of them as one ZIP. A merged result downloads as a single PDF.
Options Explained
- Optimize clears the title, author, subject and keywords, then repacks the file structure. Images are not recompressed.
- Merge All combines every file into one PDF, in the order listed. The result is saved as merged-document.pdf.
- Move up and Move down change the order of the files. They appear when Merge All is ticked, before you press Process PDFs.
- Remove takes a file out of the list.
- Clear Canvas empties the list so you can start again.
How Much Smaller Will It Get?
It depends on what is inside the PDF.
- Text-based PDFs with extra data can shrink noticeably.
- PDFs made mostly of photos or scans shrink very little, because images are not recompressed.
- If the repacked file is not smaller, you get your original file back unchanged.
Tips for Merging
- Check the order before you press Process PDFs. You cannot reorder after merging.
- Tick Optimize as well for a cleaner merged file.
- Bookmarks and form fields from the originals may not carry over to the merged file.
Privacy: How This Tool Works
- Your browser does all the work. No file is uploaded.
- Nothing is stored or shared.
- Your files disappear when you close the tab.
Frequently Asked Questions
Are my PDF files uploaded to a server?
No. Everything happens in your browser, so your files stay on your device and nobody else can see them. That makes it safe for contracts, invoices and other private documents.
How much smaller will Optimize make my PDF?
It clears the title, author, subject and keywords and repacks the file structure. Images are not recompressed, so a PDF that is mostly photos may shrink very little. The size before and after is shown for every file.
Why did my PDF not get smaller?
Most of its size is probably images or scans, and this tool does not recompress images. When the repacked file is not smaller, you get your original file back unchanged.
How do I merge PDF files into one?
Add your files, tick Merge All and press Process PDFs. The files are joined in the order they appear in the list and saved as merged-document.pdf.
Can I change the order before merging?
Yes. With Merge All ticked, use Move up and Move down next to each file. The order cannot change after processing. Press Clear Canvas and start again if you need to.
Can I optimize and merge at the same time?
Yes. Tick both Optimize and Merge All and the tool does both in one step.
How many PDFs can I add?
Up to 100 files per batch, each up to 100 MB and 500 MB in total.
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