PDF Compressor
Reduce PDF file size instantly in your browser. Choose your compression level — no uploads, no signup, 100% private.
Drop your PDF here
or click to browse
PDF files only · Max 100 MB
How It Works
Drag and drop your PDF onto the upload area or click to browse. Files up to 100 MB are supported.
Select Low, Recommended, or Maximum depending on how much size you want to save versus quality you want to keep.
Click Compress PDF and download your smaller file in seconds. See exactly how many bytes you saved.
Compression Levels Explained
Low Compression (20–40% smaller) renders each page at a high resolution with high JPEG quality. Ideal when you need the compressed file to look as close to the original as possible — great for sharing presentations or design files.
Recommended (40–70% smaller) is the best starting point for most use cases. It balances visual fidelity with meaningful file size reduction, making PDFs easier to email, upload, or share without obvious quality loss.
Maximum Compression (60–85% smaller) aggressively reduces file size by rendering at a lower scale and applying stronger JPEG compression. Best for archiving documents where readability matters more than fine visual detail, or when you need to meet a strict file size limit.
Why Compress PDFs?
Large PDF files are common when exporting from design tools, scanning documents, or generating reports with many images. Oversized PDFs can cause problems: email attachment limits are frequently set at 10–25 MB, cloud storage fills up quickly, and slow upload/download speeds frustrate recipients.
- Email attachments — most services cap attachments at 10–25 MB
- Web uploads — many platforms restrict file size for uploads
- Storage savings — smaller files mean less disk and cloud space used
- Faster sharing — compressed PDFs upload and download faster
- Mobile viewing — smaller files load faster on mobile devices
Limitations to Know
This tool works by rasterizing each PDF page — converting it to a JPEG image and reassembling a new PDF. This means:
- Text becomes non-selectable — the output is image-based, so you cannot copy text from the compressed PDF
- Best for image-heavy PDFs — text-only or vector PDFs may not shrink significantly (and could become larger)
- Password-protected PDFs are not supported
- Large files take longer — processing is done page by page in your browser
- No metadata preservation — embedded fonts, bookmarks, and hyperlinks are not retained
If you need to preserve selectable text, hyperlinks, or bookmarks, consider using a dedicated desktop PDF editor. This tool is optimized for reducing file size on scanned documents, image-rich reports, and presentation exports.
Frequently Asked Questions
Is my PDF safe when using this compressor?
Yes, 100%. All processing happens entirely in your browser using JavaScript. Your PDF file is never uploaded to any server. It stays on your device throughout the entire compression process.
How much can I compress a PDF?
It depends on the content and your chosen level. With Low compression, expect 20–40% size reduction. Recommended gives 40–70% reduction. Maximum compression can achieve 60–85% reduction. Image-heavy PDFs compress much more than text-only documents.
Will compression reduce the quality of my PDF?
This tool works by re-rendering each page as a JPEG image. Low compression preserves near-original visual quality. Recommended is a balanced trade-off. Maximum compression produces the smallest file but with noticeably reduced image fidelity. Text in the output is rendered as an image, so it will not be selectable.
What is the difference between the three compression levels?
Low Compression (scale 1.8, JPEG quality 88%) preserves the most detail with 20–40% size reduction. Recommended (scale 1.2, quality 72%) balances quality and size with 40–70% reduction. Maximum (scale 0.75, quality 52%) produces the smallest possible file with 60–85% reduction, at the cost of sharpness.
Why is my compressed PDF larger than the original?
This can happen when the original PDF is already highly optimized — for example, a text-only or vector-heavy PDF. When pages are re-rendered as JPEG images and reassembled, the result can be larger than a compact text-based PDF. Try a lower compression level, or consider that the original may already be well-compressed.
Can I compress a password-protected PDF?
No. Password-protected PDFs cannot be opened and processed by this tool. You would need to remove the password protection first using a dedicated PDF tool before compressing.
How does browser-based PDF compression work?
This tool uses PDF.js to render each page of your PDF onto an HTML canvas at a specified scale. Each rendered canvas is then exported as a JPEG image at a chosen quality level. The JPEG images are then embedded into a new PDF document created with pdf-lib. The resulting PDF is smaller because JPEG compression removes detail that is hard to perceive at screen resolution.
Is there a file size limit?
Yes, the maximum file size is 100 MB. Very large PDFs with many pages may take longer to process since each page is rendered individually in your browser. Performance depends on your device's CPU and memory.