Compress PDF
Reduce PDF file size so you can email, upload or share it easily. Runs entirely in your browser, works offline, — your file never leaves your device.
Drop a PDF file here
or click to choose — PDF
Choose PDF fileHow to compress a PDF
- Click "Choose PDF file" or drag a PDF into the box above.
- Choose a compression level — Light keeps text, Medium/Strong re-render pages as images for bigger savings.
- Click "Compress PDF" and download the smaller file.
What is "Compress PDF"?
Compressing a PDF means producing a smaller file that still opens, prints, and shares the same way the original does. PDFs grow large for predictable reasons — embedded fonts, uncompressed images, redundant metadata, or pages that were scanned at unnecessarily high resolutions. A good compressor identifies which of those costs can be reduced without breaking the document.
PDFtez gives you three levels because not every PDF should be compressed the same way:
- Light is lossless. It strips metadata, optimises the document structure, and rewrites the file with efficient encoding — but it leaves text, vector graphics, and embedded fonts untouched. Text remains selectable, searchable, and screen-reader friendly. Typical savings: 10–30%.
- Medium re-renders each page as a JPEG image at 120 DPI and rebuilds the PDF around those images. The result is visually almost identical at normal viewing zoom, but the text layer is replaced by an image — copy/paste and search no longer work. Typical savings: 60–80%.
- Strong re-renders at 90 DPI with aggressive JPEG compression. Best reserved for scans and image-heavy PDFs that will be viewed on screen or sent over email rather than printed at high quality. Typical savings: 80–95%.
When to use Compress PDF
Compression is the right tool whenever a PDF is too large for its purpose:
- Email attachment limits. Gmail, Outlook, and most corporate mail systems cap attachments around 20–25 MB. A 40 MB scanned contract becomes sendable after a Medium compression pass.
- Government and bank uploads. Many official portals (tax returns, visa applications, mortgage uploads) impose strict file-size limits — often 5 MB or 10 MB. Compressing first avoids re-scanning.
- Sharing scans over messaging. WhatsApp, Telegram, and Signal struggle with multi-megabyte PDFs. Strong compression on scanned documents brings them down to a size that uploads and previews quickly.
- Archival storage. If you store every PDF you've ever signed in cloud storage, compressing older documents recovers gigabytes without changing how they look on screen.
- Web publishing. Posting a PDF brochure or report on a website? Compressed PDFs load faster, count less toward bandwidth costs, and rank better on mobile.
- Sending photos as a PDF. A 12 MB phone-camera PDF of a receipt can shrink to under 200 KB with no meaningful loss in legibility — quicker to send, easier on the recipient's inbox.
How PDFtez compresses your PDFs (under the hood)
PDFtez's Compress tool runs entirely inside your browser. When you drop a file, your browser reads it into memory and passes it to pdf-lib for structural work, and to PDF.js (Mozilla's PDF rendering engine) when pages need to be rasterised for Medium or Strong compression. The output is built in memory and downloaded via URL.createObjectURL — no upload, no server, no logging.
The trade-off you're making at each level is visible in the result card: original size → compressed size → percentage saved. Light is always safe; Medium and Strong should be reserved for PDFs where you don't need the text layer (or where you're willing to run OCR later if you do).
How is PDFtez Compress different from other online compressors?
Most online compressors — iLovePDF, SmallPDF, PDF24, Adobe — upload your file to a server, compress it there, and return the result. That model means your PDF is briefly on someone else's infrastructure, governed by their privacy policy and retention rules. It also typically means daily limits and constant prompts to upgrade.
PDFtez does the compression on your device. Nothing leaves your computer. There is no daily limit and no premium tier. The trade-off is that very large or image-heavy PDFs may take a few extra seconds to process on your browser, where a server-based tool might do it slightly faster. For most files the operation completes in under five seconds.
Frequently asked questions
Will compression make my text uneditable or unsearchable?
It depends on the level. Light is lossless — text stays selectable and searchable. Medium and Strong rasterise each page as an image, so the embedded text layer is lost. If you need to keep text editable, choose Light; if your goal is the smallest possible file, choose Medium or Strong and run OCR later if needed.
How much will my PDF actually shrink?
It depends entirely on what's inside the file. A text-heavy report compressed at Light typically loses 10–30% of its size. A scanned 30-page contract compressed at Medium often loses 60–80%. Image-heavy PDFs at Strong frequently lose 90%+. The result card after each run shows your exact before/after numbers.
Is there a file size limit?
No hard limit. Files under 100 MB compress within a few seconds on a modern laptop. Files over 200 MB may briefly slow your browser depending on available RAM. The "Strong" level is the most computationally expensive and may take longer for image-heavy PDFs.
Can I compress password-protected PDFs?
PDFtez will attempt to read encrypted PDFs in compatibility mode. If a file is tightly locked with owner-password restrictions, use the Protect PDF tool first to remove the password (you'll need to know it), then compress.
Does it work on mobile?
Yes — Safari on iOS and Chrome on Android both work. The interface is touch-friendly. Mobile browsers have less RAM than laptops, so very large files (200 MB+) may struggle. For huge scans, run the compress on a desktop browser and transfer the result to your phone if needed.
Where do my files go? Are they uploaded?
Your files stay on your device. The compression runs entirely in your browser using JavaScript. No file data is uploaded to any server, no copy is stored anywhere, and nothing is logged. You can verify this in DevTools → Network while you compress: there will be no outgoing requests carrying your PDF data.