How PDF compression works
PDFs can be surprisingly large — especially when they contain scanned pages, photos or high-resolution screenshots. This tool compresses PDFs directly in your browser by re-encoding pages in a smaller, more efficient way while keeping them readable.
When to use this tool
Compress PDF is most useful when your file is “too big to send” or “too large to upload”. It helps you reduce size without needing desktop software or online uploads.
- Email attachments: stay under common 10–25 MB limits and avoid bounce-backs.
- Online forms & portals: fit strict file-size caps for applications, HR, government and banking uploads.
- Sharing and storage: keep folders lighter and speed up downloads for other people.
If a PDF won’t open or errors during processing, try Repair PDF. If you need a simplified “final” PDF without interactive bits, Flatten PDF pairs well with compression.
Step-by-step: compress your PDF
Reducing PDF size follows the same short routine every time:
- Add your PDF files. Drag and drop PDFs onto the box above, or click it to select files from your device.
- Choose a compression level. Balanced is a strong everyday choice that keeps files readable.
- Adjust quality and downscale (optional). Lower values shrink more, higher values preserve more detail.
- Compress the PDFs. Click Compress PDF. Everything runs locally in your browser.
- Save the smaller files. Download each compressed PDF or use Save all PDFs to save everything.
Privacy, limits and how this tool treats your files
FileYoga is built around a simple rule: your files stay with you. This compression tool follows that rule closely.
Local-only compression
Your PDFs are processed in your browser. We do not upload, scan or store your files on FileYoga servers.
No hidden copies
When you clear the list or close the tab, the tool stops using your files and does not save copies on a server.
No artificial limits
No paywalls or quotas. The only limits come from your device’s memory and your browser.
No account required
Use the tool without signing up. Open the page, compress your PDFs, and leave when you are done.
Limits to be aware of: very large PDFs can exceed browser memory during rendering, and password-protected or restricted PDFs may fail unless you provide an unlocked copy.
Compression levels: light, balanced and strong
Compression is always a trade-off between file size and visual detail. The level slider keeps things simple while still giving you control.
Modest shrinking with strong readability and detail. A good choice for forms, contracts and documents where text clarity matters more than the smallest possible file size.
A dependable everyday setting for email and uploads. It usually gives a noticeable reduction while keeping scans and page content comfortably readable.
Maximum shrinking for large scans and image-heavy PDFs. Best when size limits are strict and you can accept a little less detail in photos or fine textures.
Quality and downscaling: when to use them
Use output quality and downscale to control the trade-off between detail and size. These are most effective for scanned/image-heavy PDFs.
- Output quality: higher values keep more detail, lower values shrink more.
- Downscale pages: reduces resolution. Try 85–90% for large scans when you need a big reduction.
Tips for best results
- For scanned PDFs, try Balanced with 85–90% downscale for a big reduction without ruining readability.
- For text-heavy PDFs, compression may be limited because the file is already efficient.
- If text looks soft, increase quality or keep downscale at 100%.
- If your PDF is huge, compress one file at a time to avoid browser memory limits.
- Password-protected or restricted PDFs may not compress unless you provide an unlocked copy.
Troubleshooting
- Compression doesn’t reduce size: Text-only PDFs are often already optimized. This tool helps most with scanned/image-heavy pages.
- Output looks blurry: Increase Output quality or keep Downscale at 100%, then compress again.
- Tool fails or freezes: The PDF may be very large or complex. Try one file at a time, reduce downscale (e.g., 85–90%), or close other heavy tabs.
- Password / permission errors: The PDF may be encrypted or restricted. Use an unlocked copy, or remove restrictions in your PDF editor if allowed.
- Need searchable text or working forms: Compression may flatten pages into images and drop interactive features. Consider Light settings or keep the original for editing/search.
Frequently asked questions
No. Compression runs locally in your browser. Your PDF files are not uploaded to FileYoga servers.
Scans are essentially images, so reducing image quality and/or resolution often cuts size dramatically. Text-only PDFs are frequently already optimized and may not shrink much.
Not always. If compression rebuilds pages from images, text search/selection may be lost. If you need searchable text, keep lighter settings or keep the original PDF for search and editing.
Not always. Interactive elements can be flattened or removed during compression. If you must keep forms/links, test one file first and keep the original as your editable copy.
Sometimes no. Encrypted or permission-restricted PDFs may fail unless you provide an unlocked copy that your browser can render and process.
Start with Balanced, quality around High, and downscale at 90% for scans. If it’s still too big, lower quality one step or downscale to 85%.
Large scans require rendering many high-resolution pages, which can exceed browser/device memory. Try one file at a time, use downscale (85–90%), and close other heavy tabs.
Use Light or Balanced with higher output quality and avoid aggressive downscale. Test-print a page if quality is important.