How to Batch Compress Multiple PDFs Offline

Aug 21 2026

PDF Creation

7 min

How to compress multiple PDF files at once offline

To batch compress PDF files offline, in Xodo PDF Studio and go to the Batch tab > Optimize. Choose a preset or custom optimizer profile. Add your PDF files or a folder of PDFs. Select a separate destination, and start the batch process. Afterwards, review the file size and document behavior before replacing any originals.

PDF compression vs. optimization vs. ZIP compression: What’s the difference?

PDF compression commonly reduces file size by recompressing or downsampling images.
PDF optimization can go further by changing the PDF itself (removing selected objects, merging duplicate images, flattening certain interactive content).
ZIP compression is another method to note. It differs from both by packaging files for storage or transfer without rewriting the content inside each PDF.

How to choose a test file and PDF optimizer profile

Before processing the full batch, test out one optimizer profile that closely suits the content, quality needs, and intended use of your PDFs.

How to choose a PDF optimizer profile

Xodo PDF Studio includes three default profiles: Light, Balanced, and Aggressive. Here's a quick look at which one to use:

Profile	Good starting point	Main QA concern
Light	PDFs where higher image quality is a priority	Smaller size savings; confirm the result meets your target
Balanced	Standard office documents and general sharing	Flattens comments, which can affect review workflows
Aggressive	Large PDF files intended for tight storage or transfer limits	Reduces image quality, removes comments, attachments and metadata, and flattens form fields

You can also create your own reusable custom profile, giving you more control. In Xodo PDF Studio, go to Document tab > Optimize. Select <new profile>. Configure the optimizer settings to compress your PDF. Save the profile and it will then be listed as an optimizer profile you can select.

How to test a PDF optimizer profile before batch compressing

To test an optimizer profile:

Choose a representative higher-demanding PDF file in your batch.
Run an optimizer profile on it.
Save the optimized test as a new copy.
Compare it with the original file at normal viewing size and at closer zoom.
Use the Audit to verify which document elements are still using the most space.
Review the Optimizer Results to see what actions Xodo PDF Studio took on the file to see where changes can be made to the profile.

If the results are acceptable, you can use the profile to batch optimize PDF files.

How to batch compress PDF files in Xodo PDF Studio

To compress multiple PDF files with Xodo PDF Studio, follow these steps:

Download and install Xodo PDF Studio on Windows, macOS, and Linux.
After installation, go to the Batch tab > Optimize.
Choose Light, Balanced, Aggressive, or your own customized profile.
Add your files, by clicking on Add Files or Add Folder.
Choose a destination folder.
Keep source filenames or set a new filename pattern.
Click on Start to begin the process.

Steps for batch compressing PDF files with Xodo PDF Studio on Windows, macOS, and Linux

A few tips to streamline your workflow:

Enable Preserve Folder Structure if the source hierarchy needs to remain intact.
Avoid Overwrite Files unless the profile and output have passed review.
Split significantly different document types into separate batches.

If file-size reduction is only one part of a multi-step process, you can automate repetitive PDF tasks using the Action Wizard. For compression alone, the Batch Optimize option provides the more direct workflow.

If you only need to reduce one file and uploading it fits your workflow, see how to compress a PDF online.

How to check PDF quality after batch compression

Once optimized, review the differences of your compressed files:

Clarity: Inspect fine print, signatures, stamps, diagrams, and image-heavy pages.
Searchability: Search for a known phrase and confirm scanned documents still work as expected.
Links and navigation: Test important links and bookmarks.
Forms and comments: Confirm interactive fields and annotations remain available when required.
Attachments and metadata: Check that anything your workflow depends on is still present.

If you plan to publish the PDFs online, file size is only one factor. For those cases, you should optimize PDFs for Fast Web View so browsers can display pages before the full file downloads.

Why do some PDF files compress more than others?

Some PDFs compress more than others for different reasons. For instance:

Compression results depend on the original document.
The content itself, high-resolution images, embedded fonts, thumbnails, and uncompressed objects, can all increase PDF file size.
Also, a PDF that has already been optimized may shrink very little.

Testing optimizer profiles will help you find a suitable balance. Judge the compression result against its intended use, not by the smallest file size.

Common batch PDF compression mistakes

A few simple mistakes can lead to poor-quality output or lost document features. Some mistakes to avoid:

Using one profile for scans, forms, review copies, and print-sensitive documents.
Processing the full folder before testing a representative file.
Overwriting originals on the first run.
Choosing the Aggressive profile without checking comments, attachments, metadata, and form fields.
Ignoring files that remain too large or need separate settings.
Using high compression levels which can lower clarity in scanned PDFs.
Using lossy compression which may affect image quality.

Frequently asked questions

1. Does PDF compression change the page size or layout?

No, usually PDF compression doesn't change the page size or layout. PDF optimization typically reduces the size of internal resources such as images and fonts without changing page dimensions.

2. Can I compress PDFs to an exact file size?

No. You cannot compress PDFs to an exact output size because results depend on the content and structure of each file. If an email system has a size limit, test several profiles and adjust settings for PDFs that remain above the required threshold.

3. Can I compress a PDF before adding a digital signature?

Yes. Compress and review the PDF before signing it. Optimizing a signed PDF may invalidate its digital signature. Keep the signed version as the final copy unless another approved revision is required.

4. Does PDF compression preserve PDF/A compliance?

Yes, but not always. PDF compression may affect PDF/A compliance if it changes embedded fonts, color information, metadata, or other required elements. For archival documents, use conservative settings, keep the original files, and validate the optimized copies with a PDF/A compliance checker before storing them.

5. Can PDF optimization remove sensitive information?

PDF optimization is not a substitute for redaction or document sanitization. It may remove selected metadata or embedded elements, but doesn't reliably delete sensitive content. Use proper redaction and sanitization tools to remove sensitive content, then optimize and inspect the PDF.

6. Can Xodo PDF Studio process password-protected PDFs?

Yes. Xodo PDF Studio can try up to four authorized open passwords during a batch process. A protected or locked PDF must be successfully unlocked before it can be optimized.

Reduce repetitive PDF compression work with Xodo PDF Studio

A reliable batch-compression workflow is simple: analyze a representative file, test the profile, process copies, and inspect the outputs before replacing originals.

Compressing PDFs offline with Xodo PDF Studio can retain file security and privacy. As a bulk PDF compressor desktop, it can batch optimize files locally with reusable profiles, folder input, and destination controls. Perfect for managing large folders of PDFs.

Start Xodo PDF Studio free and compare file-size savings with the clarity and functionality your documents require.

Reena Cruz

PDF Productivity Expert