How to Fix PDF File Size Increasing After Digital Signing
Question details
The user needs to understand why signing a PDF drastically increases its file size and how to prevent this issue so the document meets file size limits for submissions.
- Product
- Device & OS
- not provided
- Scenario
- Adding a digital signature to a PDF document for official submission or sharing via email.
- Observed behavior
- The PDF file size increases exponentially (e.g., adding several megabytes per signature), causing receiving organizations to reject the file because it is too large.
Before modifying signature settings, ensure your organization permits the exclusion of revocation status data or the use of lower-resolution signature images, as these changes might affect strict compliance requirements.
Adjust Signature Creation Preferences in Adobe Acrobat
Prevent unnecessary data like revocation status and high-resolution images from inflating the PDF file size during the signing process.
Acrobat may embed extensive revocation data, signature details, and high-resolution appearance images by default. Adjusting these settings reduces the footprint of each applied signature.
Go to Edit > Preferences (or Acrobat > Settings on Mac) and select the 'Signatures' category on the left panel.
Under the 'Creation & Appearance' section, click the 'More...' button next to Creation.
Deselect the option 'Include signature's revocation status when signing' if your validation policies allow it. This prevents the software from embedding bulky certificate validation data.
Edit your signature appearance profile to remove or replace high-resolution background images or custom logos with simpler, low-file-size graphics.
Use WPS PDF for Lightweight Digital Signatures
WPS PDF offers a streamlined digital signature feature that applies secure signatures without unnecessarily bloating your file size. It ensures your signed documents remain compact, professional, and easy to share.
- 1. Open your PDF in WPS Office: Launch WPS Office and open the PDF document you need to digitally sign.
- 2. Access the signature tool: Navigate to the 'Protect' or 'Fill & Sign' tab on the top ribbon and select the 'Sign' option.
- 3. Create or apply a lightweight signature: Choose an existing signature or create a new one using plain text, the drawing tool, or a low-resolution image to save space.
- 4. Apply and save: Place the signature in the desired location and save the document. The resulting file will remain compact and ready for submission.
Frequently Asked Questions
Why does a digital signature add so much size to my PDF?
A digital signature increases file size because it often embeds complex cryptographic data, revocation status information (CRL/OCSP), rich signature metadata, and high-resolution appearance images into the document structure.
Can I compress a PDF after it has been digitally signed?
Generally, compressing a digitally signed PDF using standard compression tools may invalidate the signature, as compression alters the file's underlying byte structure. It is better to compress the document before signing or adjust the signature creation settings to prevent bloat.
Will removing the revocation status make my signature invalid?
Removing the embedded revocation status does not necessarily make the signature invalid. However, it means the recipient's PDF reader will need an active internet connection to check the certificate's validity online when they open the document. Always verify with your receiving organization's compliance rules.
How can I reduce the file size of my signature appearance?
Instead of using high-resolution scanned images or complex company logos for your signature appearance, use a simple hand-drawn signature using your mouse/stylus, plain text, or a heavily compressed, low-resolution JPEG/PNG image.
