Compress PDF
Optimize structure and downsample images for aggressive size reduction.
Drop PDF here or click to browse file
Supports PDF files only
How to compress a PDF online
Large PDFs are slow to email and awkward to upload. PDF62's compressor shrinks them by optimizing the document structure and downsampling embedded images — all inside your browser, so the file never leaves your device. There's no sign-up, no watermark, and no size cap.
- 1
Open the Compress tool
Drop your PDF onto the upload area above, or click to browse for a file on your device.
- 2
Choose your quality
Use the JPEG quality slider to balance sharpness against size, and the image scale slider to downsample high-resolution images.
- 3
Compress the file
Click Compress PDF. The work happens locally on your device, so even large files are processed without waiting on an upload.
- 4
Download the result
Compare the original and compressed sizes, then download your smaller PDF. Re-run with different settings any time.
Why compress PDFs with PDF62
- 100% private: your file is processed in your browser and is never uploaded to a server.
- No limits: compress as many PDFs as you like, with no file-size caps or accounts.
- Adjustable quality: fine-tune image quality and scale to hit your target size.
- Works offline: once the page has loaded, you can compress without an internet connection.
Frequently Asked Questions
Does compressing a PDF reduce its quality?
It can, depending on your settings. Text and vector content stay crisp, but images are re-encoded — lowering the JPEG quality or image scale shrinks the file more at the cost of some image detail. For most documents the balanced range is visually lossless.
How much smaller will my PDF get?
It depends on what is inside. Scanned or image-heavy PDFs often shrink by 50–80%, while text-only files that are already optimized may only drop a little. Try a couple of quality levels to find the best trade-off.
Is it safe to compress confidential documents?
Yes. PDF62 compresses your file entirely in the browser using WebAssembly, so the document never leaves your computer — nothing is uploaded, stored, or seen by us.
Is there a file size limit?
There is no hard limit imposed by PDF62. Because processing happens on your own device, the practical ceiling is your computer's available memory.
Why is my PDF so large in the first place?
Usually high-resolution scanned pages or embedded images. Compressing downsamples those images to bring the size down without changing the text.