How to Reduce PDF Size When Embedded Fonts Use Most of the File
Question details
The user needs to reduce the file size of a PDF where embedded fonts account for the majority of the file size, without breaking the document's visual rendering.
- Product
- Device & OS
- not provided
- Scenario
- Trying to share or store a PDF file that is unusually large due to heavy font embeddings and multiple font subsets.
- Observed behavior
- The PDF file size is heavily inflated because multiple font styles (like regular, bold, and italic) are embedded as separate resources, causing storage and sharing difficulties.
Before attempting optimization, save a backup copy of your original high-quality PDF, as aggressive compression or font removal may alter document rendering or remove accessibility tags.
Adjust Export Settings in the Source Application
The safest and most effective way to reduce PDF size is to adjust the font embedding and subsetting settings directly in the original document editor before exporting.
Different font styles (like Regular, Bold, and Italic) are distinct resources, meaning they are not duplicates but individual files embedded into your PDF. Modifying export settings at the source guarantees that you only embed the necessary subset of characters.
Launch the source application (such as Microsoft Word, InDesign, or WPS Writer) and open your original document.
Navigate to 'File', select 'Export' or 'Save As', and choose the PDF format.
Look for 'Options', 'Advanced', or 'Settings' related to PDF creation. Ensure that font subsetting is enabled (e.g., 'Subset fonts when percentage of characters used is less than 100%').
Export the new PDF file. This ensures only the exact characters used in the document are embedded, significantly decreasing file size.
Use Built-in PDF Optimization Tools
If you do not have access to the original source file, you can use dedicated optimization tools in professional PDF editors to reduce the file size.
Print to a Virtual PDF Printer
As a last resort, recreating the PDF by 'printing' it to a virtual PDF printer can flatten the document and strip out heavy backend data.
Compress PDFs Quickly with WPS Office
WPS Office features a powerful built-in PDF compression tool that helps you easily reduce large PDF files caused by embedded fonts and high-resolution media, without losing layout compatibility.
- 1. Open the PDF: Launch WPS Office and open your heavy PDF document.
- 2. Select the Compress tool: Navigate to the 'Tools' tab on the top ribbon and click on 'Compress'.
- 3. Choose optimization level: Select your preferred compression level (e.g., HD, Normal, or Basic) based on your file size requirements.
- 4. Compress and save: Click 'Compress' to process the file, then save the optimized, smaller PDF to your device.
Frequently Asked Questions
Why do font styles like bold and italic increase my PDF size so much?
Font weights and styles, such as Regular, Bold, and Italic, are treated as entirely distinct resources within a PDF. Embedding multiple styles of the same font family requires embedding multiple separate font files, which significantly increases the total document size.
Should I manually remove embedded fonts to save space?
Generally, it is not recommended unless you are removing common system fonts. Removing required embedded fonts can cause the PDF to display incorrectly on devices that do not have those specific fonts installed. Using font subsetting is a much safer alternative.
What does 'subsetting' a font mean when exporting to PDF?
Subsetting means embedding only the specific characters (such as particular letters, numbers, and symbols) that are actually used in the document, rather than the entire font character set. This drastically reduces the file size while seamlessly maintaining the document's appearance.
