How to Reduce PDF Size Without Losing Quality

Quick answer 

To reduce PDF size, compress the file with an online PDF compressor or use a PDF optimizer to remove or compress the content taking up the most space. For the fastest option, upload the PDF to Foxit’s online compressor. For more control, Foxit PDF Editor can reduce file size with default settings or let you optimize images, fonts, and other PDF data individually. 

Why is my PDF file so large? 

PDF file size usually grows because of high-resolution images, scanned pages, embedded fonts, multimedia, attachments, metadata, or other document objects. A PDF created for professional printing can also be much larger than a version meant only for email or online viewing. 

The right way to make a PDF smaller depends on what is making it large. A simple compressor works well for most files. Image-heavy, scanned, or complex PDFs may benefit from advanced optimization so you can reduce the biggest elements without unnecessarily lowering the quality of everything else. 

Common reasons to reduce a PDF file size include: 

• Meet an email attachment or upload limit. 

• Speed up uploads, downloads, and mobile viewing. 

• Reduce cloud or local storage use. 

• Share scanned or image-heavy documents more easily. 

• Prepare large PDFs for websites, portals, or document management systems. 

How to reduce PDF size online 

If you need a smaller PDF quickly, an online PDF compressor is usually the simplest option. Foxit’s online tool works in a browser and does not require software installation. 

1. Open Foxit’s Compress PDF tool.
2. Drag and drop your PDF into the compressor or click to select a file.
3. Click Start Compression.
4. When compression finishes, click Download Your File to save the smaller PDF.

Use the Compress PDF tool when you want a fast, browser-based way to shrink a PDF file without manually changing optimization settings. 

How to reduce PDF file size with Foxit PDF Editor 

For PDFs you work with regularly, Foxit PDF Editor gives you a quick Reduce File Size command plus advanced controls when you need more precision. 

Option 1: Reduce file size with default settings 

The Reduce File Size command applies default optimization settings that are suitable for a wide range of documents. 

1. Open the PDF in Foxit PDF Editor.
2. Choose File > PDF Optimizer > Reduce File Size.
3. Choose Current File. Under PDF Version Compatibility, keep the existing version or choose the version you need.
4. Choose the compression effect you want, then click OK.
5. Choose a file name and save location for the optimized PDF.

Best for: everyday PDFs when you want a smaller file without manually tuning individual image, font, or object settings. 

Option 2: Use Advanced Optimization for more control 

If the PDF is still too large, Advanced Optimization lets you see what consuming space is and decide what to reduce. 

1. Choose File > PDF Optimizer > Advanced Optimization > Advanced Optimization.
2. Click Audit space usage to see which types of content take up the most space in the PDF.
3. Choose the PDF version compatibility you need.
4. Select the categories you want to optimize and adjust their settings. Common targets include images, embedded fonts, transparency, objects, and user data.
5. Save the optimized PDF as a new file, then compare it with the original.

Best for: large, image-heavy, scanned, or complex PDFs where file size matters but you also need control over quality and document content. 

7 ways to make a PDF smaller 

1. Compress the PDF 

Compression is the fastest general-purpose way to decrease PDF size. A compressor analyzes the file and reduces data where possible, especially in images and repeated or unnecessary content. Start here when you simply need a smaller PDF for sharing or uploading. 

2. Downsample or compress large images 

Images are often the largest part of a PDF. Downsampling lowers image resolution, while image compression reduces the amount of data required to store the image. Stronger settings usually create smaller files, but they can also reduce visual detail. 

For documents viewed mainly on screens, you often do not need print-level image resolution. Keep higher resolution when the PDF contains detailed diagrams, fine print, signatures, medical images, engineering drawings, or content that will be professionally printed. 

3. Remove unnecessary embedded fonts 

Embedded fonts help a PDF look consistent on different devices, but they also add data. If a document contains multiple fonts or large font subsets, unembedding unnecessary fonts can reduce file size. Check the finished PDF carefully to confirm that the text still displays correctly. 

4. Remove unused objects and user data 

Complex PDFs can contain attachments, comments, hidden layers, metadata, alternate images, embedded thumbnails, scripts, or other objects you no longer need. Removing unused content can reduce PDF file size without changing the visible pages but only delete items you are sure the document no longer requires. 

5. Optimize scanned PDFs 

Scanned PDFs can become very large because each page is stored as an image. Reduce the image resolution or use scan-specific compression to make the document smaller. If the scan needs searchable text, use OCR so people can search or copy text without keeping unnecessarily high-resolution page images. 

6. Use Save As when repeated edits have increased file size 

Repeated edits can sometimes leave behind document data that increases file size. Saving a new copy may produce a cleaner file structure. This is not a substitute for compression, but it can help when an edited PDF is unexpectedly larger than an earlier version. 

7. Remove pages or content you do not need 

If the PDF contains duplicate pages, outdated appendices, unused attachments, or other unnecessary content, removing it reduces file size at the source. This is often the best approach when the goal is a smaller file without lowering the quality of the pages that remain. 

How to reduce PDF file size without losing quality 

Any method that removes data can affect quality, so the goal is usually to reduce file size without making the document harder to read or use. Start with the least aggressive option and only increase compression if the file is still too large. 

• Keep the original PDF as a backup before optimization. 

• Start with standard or moderate compression instead of the strongest setting. 

• Check small text, charts, signatures, screenshots, and images at 100% zoom after compression. 

• Use Advanced Optimization when you need to target the biggest file components instead of compressing everything equally. 

• Avoid repeatedly compressing an already compressed PDF, which can compound image-quality loss. 

• For scanned documents, balance resolution with readability and use OCR when searchable text is important. 

Which PDF compression method should you use? 

Method	Best for	Trade-off
Online PDF compressor	Quick one-time compression	Fastest option, with less granular control.
Reduce File Size	Routine desktop compression	Easy and consistent but uses broader preset settings.
Advanced Optimization	Large or complex PDFs	More control but requires you to choose what to optimize.
Image optimization	Scans and image-heavy PDFs	Can produce major savings, but aggressive settings may reduce image detail.
Remove unused content	PDFs with extra pages, objects, or data	Preserves remaining quality, but removed content may be difficult or impossible to restore.

How small should a PDF be? 

There is no single ideal PDF file size. The right size depends on how the file will be used. A document for email or a web portal may need to fit a strict attachment limit, while a high-resolution print file can be much larger. 

• Email: aim below the recipient’s attachment limit, leaving room for message overhead and other attachments. 

• Web upload: follow the portal’s stated MB or KB limit. 

• Mobile sharing: smaller files generally upload and open faster on slower connections. 

• Archiving or printing: prioritize legibility and required quality standards rather than pursuing the smallest possible file. 

Frequently asked questions about reducing PDF size 

How do I reduce PDF size quickly? 

Use an online PDF compressor. Upload the PDF, start compression, and download the smaller file. If you work with PDFs frequently, the Reduce File Size command in Foxit PDF Editor provides a fast desktop option. 

How do I make a PDF smaller without losing quality? 

Start with moderate compression and check the result before using stronger settings. For more control, use Advanced Optimization to target images, fonts, or other large elements instead of applying maximum compression to the entire document. 

Why is my PDF so large? 

Large PDFs often contain high-resolution images, scanned pages, embedded fonts, attachments, metadata, multimedia, or other objects. Auditing what takes up space can help you choose the best way to reduce the file. 

Can I reduce PDF size online for free? 

Yes. Foxit offers an online PDF compressor that lets you upload a PDF, compress it in the browser, and download the smaller file. 

How do I shrink a scanned PDF? 

Optimize the scanned page images by reducing resolution or applying scan-friendly compression. If you need searchable text, run OCR so the document remains useful even after image optimization. 

Does compressing a PDF change the page size? 

No. File compression reduces the amount of data stored in the PDF. It does not normally change the physical page dimensions such as Letter or A4. 

Can I reduce a PDF to a specific size such as 2 MB? 

Compression can substantially reduce a PDF, but hitting an exact target depends on the document. Use progressively stronger compression or Advanced Optimization while checking quality until the file is below the required limit. 

What is a PDF size reducer? 

A PDF size reducer is another name for a PDF compression or optimization tool. It decreases the amount of data in a PDF, so the file is easier to upload, email, store, or share. 

Reduce PDF size with the right level of control 

For most files, start with simple compression and review the results. If the PDF is still too large, identify what is consuming the most space and optimize those elements individually. This approach gives you a smaller file while protecting the text, images, and formatting that matter. 

For advanced compression, image optimization, OCR, and ongoing editing in one workflow, use Foxit PDF editor.