Compress PDF Online Free
Reduce PDF file size with professional Ghostscript compression — choose a quality level, click Compress, and download. No signup. Files are processed securely and deleted immediately. Supports PDFs up to 4 MB.
How to Compress a PDF
- 1Click the drop zone or drag your PDF file onto it.
- 2Choose a compression level: Low for best quality, Medium for everyday sharing, or High for the smallest possible file.
- 3Click Compress PDF. Your file is uploaded over a secure connection and compressed with Ghostscript on our server.
- 4When complete, the file size comparison shows your original size, the compressed size, and the percentage saved. Click Download compressed PDF to save it.
Professional-Grade Compression
This tool runs Ghostscript, the same PDF engine used by print shops and publishing workflows worldwide. Rather than flattening your pages into images — the shortcut many browser-based compressors take — it intelligently re-samples embedded images, strips redundant data, and re-compresses internal streams while keeping your text selectable and your vector graphics crisp.
Your file is processed on our secure server and deleted immediately after the compressed PDF is returned. We never store, log, or retain your documents. The maximum file size is 4 MB per upload.
When to Use Each Compression Level
| Level | Ghostscript Preset | Best For | Typical Size Reduction |
|---|---|---|---|
| Low | printer (300 DPI) | Professional print, legal documents, signed contracts | 10–30% |
| Medium | ebook (150 DPI) | Email attachments, online sharing, general office use | 30–60% |
| High | screen (72 DPI) | Archiving, uploading to portals with strict size limits | 50–80% |
Tips for Compressing PDFs Effectively
Start with Medium
Medium (150 DPI) works well for most everyday documents. Only switch to High if you still need a smaller file, or to Low if print quality is critical.
Scanned PDFs Compress Best
Scanned documents are stored as high-resolution images. Ghostscript re-samples those images to your chosen DPI, which typically produces the largest savings — often 60–80%.
Text Stays Selectable
Unlike image-based compressors, Ghostscript preserves the real text layer. Your compressed PDF remains searchable and the text can still be copied — at every quality level.
Already-Optimised Files
If a PDF is already compact, there may be little left to remove. The tool detects this and lets you keep the original rather than handing back a larger file.
Remove the Password First
If your PDF requires a password to open, remove it with a PDF password remover before compressing. Encrypted files cannot be processed.
Compress Before Merging
If you plan to merge several PDFs into one, compress each individually first. The merged result will be much smaller than compressing after merging.
Frequently Asked Questions
How does the PDF compressor work?
The tool uses Ghostscript — the industry-standard PostScript and PDF engine — running on our server. It re-samples embedded images to an optimal resolution for your chosen quality level, removes duplicate and unused objects, and re-compresses the document's internal streams. Unlike browser-based compressors that flatten pages into images, Ghostscript keeps real text, vector graphics, and document structure intact, so the result stays sharp and selectable.
Is my PDF kept on your server?
No. Your file is uploaded over an encrypted connection, processed in an isolated temporary directory, and deleted immediately once the compressed file is returned. We do not store, log, or retain your documents. See our Privacy Policy for details.
What is the difference between Low, Medium, and High compression?
Low maps to Ghostscript's 300 DPI "printer" preset — high quality suitable for printing, with moderate size reduction. Medium uses the 150 DPI "ebook" preset, a balanced choice for email and online sharing. High uses the 72 DPI "screen" preset for maximum compression and the smallest possible file, best for archiving or strict upload limits.
Will compressed text still be readable?
Yes. Because Ghostscript preserves the original text and vector content rather than converting pages to images, text remains crisp, selectable, and searchable at every quality level. Only embedded raster images are down-sampled, and at Low or Medium settings the difference is rarely noticeable.
Are links, forms, and bookmarks preserved?
In most cases, yes. Because the document structure is retained rather than rasterised, hyperlinks, bookmarks, and the text layer are typically preserved. Interactive form fields and digital signatures may be altered or removed depending on the source PDF, so keep your original if you rely on those.
Can I compress a password-protected PDF?
PDFs that require a password to open cannot be processed. Remove the password first using a PDF password remover, then compress the unlocked file.
How much will the file size be reduced?
Reduction depends heavily on the content. Scanned documents and image-heavy PDFs commonly shrink by 50–80%. PDFs that are already optimised, or that contain only compact text, may reduce only slightly — if Ghostscript cannot reduce the file further, the tool tells you and lets you keep the original.
Is there a file size limit?
The maximum upload size is 4 MB per file. Most documents — invoices, reports, presentations, and forms — fall within this limit. For larger PDFs, consider splitting them first using our PDF Splitter tool.