Compress PDF Online
Shrink PDF files with Ghostscript — 4 quality presets plus optional grayscale, metadata and annotation stripping. Files are deleted after 24 hours.
How It Works
This tool runs Ghostscript on the server — the same PDF engine used by most professional compression tools. Almost all size savings come from re-encoding and downsampling embedded images, which make up 80-95% of a typical PDF.
The 4 Presets
Low keeps 300 DPI images and quality around 90 — indistinguishable from the original when printed. Medium downsamples to 150 DPI (quality ~75), the sweet spot for on-screen reading. High drops to 72 DPI (quality ~60) for email attachments. Maximum applies aggressive JPEG compression on top for the absolute smallest file — visibly softer but still readable.
Size Preview
As soon as you pick a source PDF, the tool analyses embedded images and displays an estimate for each preset. Estimates are approximate (±15%) — the actual result may differ, especially on PDFs that mix vector text with rasterized scans.
Encrypted PDFs
If the source PDF is password-protected, you'll see a password field. Enter the password and the tool decrypts it, compresses it, and returns the compressed file without encryption. If you want the compressed output password-protected too, apply the PDF Protect tool afterwards.
Privacy
By using this tool, you confirm that you are the rightful owner of the PDF or have authorization to modify it. All uploaded and compressed files are automatically deleted after 24 hours.
Frequently Asked Questions (FAQ)
Q: How much can I expect to save?
A: Image-heavy scanned PDFs usually shrink by 60-85% on Medium. Text-only PDFs already use tiny amounts of space and may only save 1-5%.
Q: Is compression lossy?
A: Yes — images are re-encoded at lower quality and resolution. You cannot reconstruct the original from a compressed file. Keep the original safely stored.
Q: Can I compress password-protected PDFs?
A: Yes. Enter the password when prompted. The compressed output has no password; add one via PDF Protect if needed.
Q: What if compression makes the file larger?
A: The tool discards the result and tells you the PDF is already optimal. No file is added to your list.
Q: What does "Convert to grayscale" do?
A: Forces all colors to black-and-white. Saves an extra 30-60% on color-scanned monochrome documents.
Q: What is the maximum file size?
A: 100 MB per file. Large PDFs can take 30-60 seconds on the server.
Q: Is my data safe?
A: Files are session-isolated and automatically deleted after 24 hours. Passwords (when provided for encrypted PDFs) are used once and never logged.
Q: Is this tool free?
A: Yes, completely free with no registration required.