Upload your PDF
Choose one PDF from your device, Google Drive, Dropbox, or a public URL. The current upload limit is shown in the workspace.
Compress PDF Online for Free
Compress a PDF for free with Light, Balanced, or Strong optimization. If the candidate is not smaller, the original file is kept.
- Free to use
- No account required
- No watermark
- Automatic file deletion
- Three compression levels
Drop PDF file here
Or click the button to choose a file from your computer
Or choose from
Three simple steps
How to compress a PDF online
Choose how strongly to reduce resources and images, then compare the result with the original.
Choose a compression level
Use Light for fidelity, Balanced for the default tradeoff, or Strong for more aggressive image compression.
Download and compare
The result shows the before and after size. Review image clarity before replacing an important original.
Compression behavior
Reduce PDF size without pretending every file compresses the same
The result depends on what the PDF contains. Image-heavy files often offer more room to shrink than text-only or previously optimized PDFs.
Three clear levels
Light, Balanced, and Strong settings let you choose between visual fidelity and a more aggressive size reduction attempt.
Original kept when smaller is impossible
If the optimized candidate is not smaller, PDFreevert returns the original PDF bytes instead of delivering a larger file.
Unused resources removed
The engine removes unused objects and streams, links duplicate streams, and reuses page content where possible.
Fonts remain embedded
Compression does not intentionally unembed fonts, helping text display consistently in the resulting PDF.
Page count verified
The result is reopened and its page count is checked against the source before it is accepted.
Browser-based workflow
Compress and download from a modern browser without installing desktop PDF software.
Best use cases
When is PDF compression useful?
Compression is most useful when a file contains large images, duplicate resources, or unused document data.
Email attachments
Try to reduce reports, proposals, and scanned packets before attaching them to a message.
Upload limits
Prepare documents for application forms, client portals, and systems with smaller file limits.
Image-heavy scans
Scanned pages often have the greatest reduction potential, especially with Balanced or Strong compression.
Document storage
Reduce repeated storage and transfer costs for files that do not need maximum image fidelity.
Compression does not guarantee a target size. Text-heavy, vector-heavy, or already optimized PDFs may shrink only slightly; when no smaller result is produced, the original file is kept.
Choose a level
Light, Balanced, or Strong compression?
All three levels remove unused resources. Balanced and Strong also recompress images at different quality settings.
Light
Cleans unused and duplicate resources without intentionally recompressing document images.
- Best first choice when diagrams, screenshots, or photos must stay as close to the source as possible.
- May produce a small change when images already dominate the file size.
Balanced
Compresses images with the engine's quality setting of 75 while also optimizing document resources.
- A practical starting point for email, portals, and routine document sharing.
- Review small text inside screenshots and fine image details after download.
Strong
Uses the engine's image quality setting of 45 to seek a smaller candidate file.
- Useful when size matters more than preserving maximum image detail.
- Photos, scans, gradients, and small text inside images may look softer.
Private file workflow
Is it safe to compress a PDF online?
Files use controlled access while the service creates, validates, and delivers the compressed result.
Read the privacy policy →HTTPS in transit
The production website transfers source and result files over HTTPS.
Isolated processing
PDF optimization runs in a dedicated background process outside the ordinary page request.
Automatic file cleanup
Source and result files expire and are deleted under the current deployment's published retention settings.
Temporary result access
Downloading requires temporary access associated with the original upload session.
Practical guide
Get a better Compress PDF result
Prepare the source, understand the tradeoffs, and review the finished file with a focused checklist.
FAQ
Compress PDF FAQ
Is Compress PDF free, and do I need an account?
You can currently compress a supported PDF for free without creating an account. The result does not receive a watermark.
What is the difference between the three compression levels?
Light optimizes unused and duplicate resources without intentionally compressing images. Balanced uses image quality 75, while Strong uses image quality 45 for a more aggressive attempt.
Will PDF compression reduce image quality?
Balanced and Strong recompress images, which can soften photos, scans, gradients, or small text inside screenshots. Review important files after download.
Can you guarantee a PDF under 1 MB or another target size?
No. The result depends on images, fonts, vector graphics, and previous optimization. The tool does not repeatedly lower quality to guarantee a target.
Why is the compressed file the same size?
An already compact PDF may not produce a smaller candidate. In that case, the current implementation returns the original PDF bytes instead of a larger file.
Does compression remove pages or unembed fonts?
It does not intentionally unembed fonts. The result is reopened and its page count is checked against the source; the current maximum is 5000 pages.
Can I compress a password-protected PDF?
Not directly. If you are authorized to process the file, use Unlock PDF with the correct password first.
Does compression invalidate a digital signature?
A smaller rewritten result invalidates existing signatures. If the candidate is not smaller and the original bytes are retained, the original structure is not rewritten.
Is my uploaded PDF secure?
The production site uses HTTPS, temporary access, and isolated background processing. Source and result files expire under the published retention settings.