Compress PDF – Reduce PDF File Size Online | ToolTree
Compress PDF files online for free using ToolTree's PDF compression tool. Reduce PDF file size quickly while maintaining document quality.
Free Compress PDF
Reduce PDF file size without losing quality. Our engine renders each page and recompresses imagery locally in your browser — your files never leave your device.
Choose a PDF file
Max 30MB • Click or drag & drop
Waiting for upload
Upload a PDF and choose a compression level to get started.
Found this tool useful?
ToolTree is built and maintained independently. Support helps keep these tools free and improve new developer utilities.
If ToolTree saved you time today, consider supporting the project.
1How it actually compresses
Unlike tools that only strip metadata, ToolTree renders each page of your PDF into an image using the PDF.js engine, then re-encodes it as a compressed JPEG at the quality level you choose. This results in genuine, significant file size reduction.
2Choosing the right level
Low — best for documents with fine text or charts where detail matters. Medium — ideal for most reports and presentations. High — maximum savings for scanned documents being emailed or uploaded to forms.
Benefits of compressing PDFs
- Smaller File SizesEasier to store and backup.
- Faster UploadsPerfect for forms and email.
- Universal ViewWorks on all devices.
- High PrivacyZero data exposure.
Frequently Asked Questions
How does it actually reduce the size?
Each page is rendered to a canvas and saved as a JPEG at your chosen quality level. This crushes bloated internal image data, often reducing file size by 40–80%.
Is it safe to compress my PDFs here?
Yes. All processing occurs locally in your browser tab. Your document data never touches our servers.
Will text become unreadable?
On Low and Medium settings, text remains crisp and fully readable. High is best for scanned images or when minimum file size is the priority.
Can I compress large PDFs?
Yes, up to 30MB. For very large files, processing may take a minute as each page is rendered and optimized individually.