How to use Compress PDF
- 1
Drag and drop your PDF files into the upload area, or click “Select files”.
- 2
Check the options — they are already pre-set for this page.
- 3
Click “Compress PDF”. Your file is processed in RAM in a few milliseconds.
- 4
Download the result, or continue with another tool without uploading again.
🛡️ Zero-Storage Architecture
Your files are processed in volatile RAM and never written to disk.
- ✓ In-memory processing, memory released immediately
- ✓ No account, no copy kept, no document logs
- ✓ HTTPS encryption in transit
Compress a PDF to a specific size
| Target | Typical use |
|---|---|
| Compress PDF to under 50 KB | |
| Compress PDF to under 100 KB | |
| Compress PDF to under 150 KB | |
| Compress PDF to under 200 KB | |
| Compress PDF to under 300 KB | |
| Compress PDF to under 500 KB | |
| Compress PDF to under 1 MB | visa application, passport scan |
| Compress PDF to under 2 MB | US visa application, job application, receipts, invoices, school assignment |
| Compress PDF to under 5 MB | university application, tax return, rental application |
| Compress PDF to under 10 MB | email attachment, court filing |
Frequently asked questions
Can every PDF be compressed under 50 KB?+
Scanned documents and photos usually shrink a lot because their images are re-encoded. Text-only PDFs are already compact; if 50 KB cannot be reached, you get the smallest possible version and we tell you so.
Is Compress PDF really free?+
Yes. UnboltPDF is free and unlimited: no sign-up, no watermark, no daily quota. The service is financed by advertising.
Are my files safe?+
Your files are processed in volatile memory (RAM) and are never written to a disk. The memory is released as soon as the result is sent back to you. We do not keep copies or log document contents.
What is the maximum file size?+
You can upload up to 50 MB per task, and up to 40 files for tools that accept several files.
Does it work on phones, Mac and Windows?+
Yes. Everything runs in your web browser: Chrome, Safari, Firefox and Edge on desktop, Android and iPhone. Nothing to install.
Popular uses
- Compress PDF for visa application
- Compress PDF for US visa application
- Compress PDF for email attachment
- Compress PDF for job application
- Compress PDF for university application
- Compress PDF for tax return
- Compress PDF for bank statements
- Compress PDF for receipts
- Compress PDF for passport scan
- Compress PDF for rental application
- Compress PDF for invoices
- Compress PDF for school assignment
- Compress PDF for court filing