Compress a PDF now
PRIVATE TOOLNo upload. Works in your browser.
Need more? Batch · Sign · Merge · JPG to PDF. Get the app ->
Pick a PDF to begin.
100% private — files stay on your device
Just PDF Compressor for iOS
One app for everyday PDF work.
★★★★★Save spaceCompress PDFs for sharing.
★★★★★Sign PDFsNo printing needed.
★★★★★Merge PDFsCombine files into one document.
★★★★★Batch compressCompress many PDFs at once.
★★★★★PDF toolkitJPG to PDF and PDF to JPEG.
Help & FAQ
How to make a PDF smaller safely
Pick the right quality level and avoid uploading private documents.
Quick tip: Choose PDF. Pick quality. Compress.
How do I compress a PDF, step by step?
- Choose your PDF. Click Choose PDF above or drag a file in. It stays on your device.
- Pick a quality level. Screen gives the smallest file, ebook is the best all-round choice for email and sharing, printer keeps the most detail.
- Click Compress. Just Compress makes a smaller PDF and downloads it automatically.
What do the quality levels mean?
| Setting | Image resolution | Best for |
|---|---|---|
| Screen | 72 dpi | Email, web upload, smallest size |
| Ebook | 150 dpi | General sharing — recommended default |
| Printer | 300 dpi | Printing, keeping image detail |
Why compress in the browser instead of uploading?
Many online PDF compressors upload your file first. Just Compress keeps your PDF on your device, which is better for contracts, bank statements, IDs, and medical records.
How do I compress a PDF on iPhone?
iPhones have no built-in PDF compressor. Two free options:
- In Safari: open this page on your iPhone, choose your PDF from Files, and compress it directly in the browser.
- With the app: install the free Just PDF Compressor app to compress many PDFs at once, work offline, and also sign and merge documents.
Is it really free?
Yes — the online tool is free with no sign-up and no file-size limit paywall. Output PDFs include a small Just Compress app logo watermark.
Are my files uploaded?
No. Your PDF stays on your device.
How much smaller will my PDF get?
Image-heavy PDFs often shrink 50–90% on the screen setting. Text-only PDFs are already small and won't change much.
Does it work on Mac, Windows, and Android?
Yes. It works on modern phones and computers. The app is for iPhone and iPad.