Across my last [N=30] contracts, auditors found mismatches between the executed file, the working copy, and metadata. …
Open the PDF you want to archive in Adobe Acrobat.
Select File > Save As Other > Archivable PDF (PDF/A).
CautionPDF/A conversion may remove features like audio, video, and JavaScript that are not permitted in archival PDFs.
In the PDF/A conversion dialog, choose the desired PDF/A standard (such as PDF/A-1b for basic long-term preservation).
Best practicePDF/A-1b is widely accepted for basic archival needs, but check your organization's requirements.
Click OK to convert and save the PDF as a PDF/A file.
Open the newly saved PDF/A file.
Select File > Save As Other > Reduced Size PDF.
In the Reduce File Size dialog, select the desired compatibility level (choose the lowest version that meets your needs for maximum compression).
Best practiceFor archival, using the lowest compatible version maximizes compression but may reduce compatibility with very old PDF viewers.
Click OK and save the reduced-size PDF/A file.
Best practiceBefore archiving, use File > Properties to remove unnecessary metadata and hidden data for further size reduction.
After converting to PDF/A, always review the document to ensure all essential content remains accessible and readable.
This runs in the Acrobat app - there is no separate API for this task.
Adobe Acrobat reduces PDF file size mainly by compressing images. It can also remove extra data like old versions or hidden information. When you choose 'Reduced size PDF', Acrobat looks for ways to make the file smaller without you having to pick specific settings. This is a quick way to get a smaller file for sharing.
Reducing PDF file size often makes images look bad because the compression process lowers their quality, especially their resolution (DPI). If you choose a high compression setting, Acrobat might change images to a very low DPI, like 72-100. This is fine for screens but not for printing, which needs higher quality (300 DPI). Always consider where the PDF will be used to avoid poor image quality.
The 'Low (High Quality)' compression setting is special because it tries to make the PDF smaller without changing the quality of the images. It usually reduces the file size by 10-30% by removing other extra data. Other compression levels, especially 'High', will significantly reduce image quality by lowering their resolution. So, 'Low (High Quality)' is best when you need a smaller file but absolutely must keep images looking sharp.
For a PDF with many scanned documents, start by using the 'Low (High Quality)' compression setting. This option reduces the file size by removing extra data without re-compressing your images, which helps keep details. If the file is still too large, you might need to try 'Medium' compression, but always check the document afterward to ensure important details in your scans are still clear. Remember to always work from the original file to prevent further quality loss.
Yes, you can automate reducing PDF file sizes for many documents using the Adobe PDF Services API. This allows you to programmatically compress PDFs. You can choose from 'LOW', 'MEDIUM', or 'HIGH' compression levels. This is very useful for businesses or users who need to process many files without doing each one by hand.