PDF files can become large when they contain high-resolution images, embedded fonts, or complex graphics. A 20MB PDF that's been emailed dozens of times wastes bandwidth, fills up inboxes, and exceeds attachment limits. Compressing reduces the file size by optimising images and removing redundant data.
ConvertPDF.Live's PDF Compressor uses PDF.js and pdf-lib to re-render and re-encode each page in your browser, with multiple compression presets to balance quality against size reduction.
Drag and drop or browse. The estimated compressed size is shown immediately after upload.
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Choose a compression level
Select from Low, Medium, High, or Maximum compression. The tool shows estimated output sizes for each option.
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Click Compress
The tool processes each page, re-encoding images at your chosen quality level.
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Download the compressed PDF
The output shows original vs. compressed size and the percentage reduction achieved.
Compression Modes Explained
Low compression: Minimal quality loss — good for PDFs you'll print or use professionally. Typically 10–30% size reduction.
Medium compression: Balanced quality and size. Ideal for most sharing scenarios. Typically 30–55% reduction.
High compression: Noticeable reduction in image quality — best for web display or email where file size matters more than print quality. Up to 70% reduction.
Maximum compression: Aggressive compression for the smallest possible file. Images will appear pixelated — best used only when file size is the critical constraint.
Benefits
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Email-Friendly
Get under email attachment limits (typically 10–25MB) without switching to file sharing services.
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Save Storage
Reduce cloud storage usage across Dropbox, Drive, and OneDrive significantly.
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Faster Loading
Compressed PDFs on websites and portals load faster for users on mobile or slow connections.
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Private
No upload — financial, medical, and personal PDFs are compressed locally.
Common Use Cases
📨 Email Attachments
Compress large PDF reports, brochures, or proposals to stay under email size limits.
🌐 Website Uploads
Compress PDFs before uploading to websites, portals, or CMS platforms for faster page load times.
📁 Long-Term Archiving
Reduce storage costs by compressing large archives of historical PDFs.
📱 Mobile Viewing
Smaller PDFs open faster on mobile devices and consume less data when shared over messaging apps.
Tips for Better PDF Compression
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Text-only PDFs compress very little. PDFs with mostly text are already small. The biggest gains come from PDFs with many images or photographs.
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Check the size estimate. The tool shows estimated sizes for each compression level before you commit — always check before downloading.
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Compress after merging. If you've just merged several PDFs with the Merge PDF tool, run the result through the compressor to keep file sizes manageable.
FAQs
How much can I reduce a PDF's file size? ▼
It depends on the PDF's content. Image-heavy PDFs can be reduced by 60–80%. Text-only PDFs may only reduce by 5–15% since text is already compact.
Will compression damage my PDF? ▼
Text and vector content are preserved exactly. Only raster images are re-encoded at lower quality with higher compression settings. The original file on your device is never modified.
Can I compress a scanned PDF? ▼
Yes — scanned PDFs are essentially image-only, so they respond very well to compression. You can typically achieve 50–80% reduction.
Is there a file size limit? ▼
No server limit. Very large PDFs (over 100MB) may be slow in-browser depending on your device's speed.
Ready to try it yourself?
100% free, browser-based — no upload, no sign-up, no watermark. Works instantly on any device.
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