PDF Compressor
Reduce the file size of a PDF by re-rendering its pages at a lower resolution. Choose your compression level, preview the size saving, and download the smaller PDF — entirely in your browser.
Drop a PDF here, or click to browse
Works best on PDFs with large embedded images
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Original size
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Compressed size
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Size reduction
This PDF is already well-optimised — the compressed version is not significantly smaller. Try a lower compression level, or the file may be text-only (which doesn't benefit from image compression).
How PDF Compression Works
This tool compresses PDFs by re-rendering each page as a JPEG image at a reduced resolution and quality, then repacking those images into a new PDF. This approach is most effective when the original PDF contains large, high-resolution embedded images — the most common cause of large PDF file sizes.
The resulting PDF is technically a "rasterised" PDF — each page is a single flat image rather than a mix of text, vector graphics, and images. This means:
- Text is no longer selectable or searchable in the compressed output
- The visual appearance is very close to the original, but fine text may look softer at high zoom levels
- File size reduction can be dramatic — often 50–90% — for image-heavy PDFs
For PDFs that are primarily text and vector graphics (like a Word document saved as PDF), the size reduction will be minimal because there are no large images to compress.
When to Compress a PDF
- Email attachments — many email systems have a 10 MB or 25 MB attachment limit
- Online form uploads — government and HR portals often cap uploads at 2–5 MB
- Web hosting — smaller PDFs load faster when served from a website
- Cloud storage — reducing file sizes saves storage quota
Compression Level Guide
| Level | DPI | Quality | Best for |
|---|---|---|---|
| Screen | 72 | 60% | Viewing on screen only; not for printing |
| eBook | 96 | 75% | Email, web sharing, general use |
| Printer | 150 | 85% | Desktop printing |
| Prepress | 200 | 92% | Professional printing |
Frequently Asked Questions
Why is the compressed file not smaller?
If the PDF contains mostly text and vector graphics (not photos or scanned images), image compression has little effect. Text-based PDFs are typically already compact and won't shrink significantly with this approach.
Can I still search the text after compression?
No. The rasterisation process converts each page to an image, which removes the text layer. If searchable text is important, keep the original PDF alongside the compressed version.
Is there a page limit?
There is no hard limit. Very long PDFs (hundreds of pages) will take longer to process since each page is rendered individually. The time scales roughly linearly with page count.
