How to use
- 1Drop a PDF file on the box or click to choose one.
- 2Choose Lossless (keeps text) or Strong (converts pages to images).
- 3For Strong mode, set the JPEG quality and resolution (72–200 DPI).
- 4Click “Compress PDF”, compare the sizes and download the result.
Two compression modes
Lossless mode re-saves the document with pdf-lib using compressed object streams. Text, fonts, links and image quality stay exactly the same; the saving is usually small and is largest for files exported by older software. Strong mode renders every page with pdf.js and rebuilds the PDF from JPEG images at the quality and resolution you choose. For scanned documents and image-heavy files this usually shrinks the file substantially, but text can no longer be selected or searched, and links and form fields are lost. In Strong mode the tool also runs the lossless pass and keeps whichever version is smaller.
Choosing quality and resolution
For documents that will only be read on screen, the defaults — 100 DPI at 60% quality — are usually legible and small. Use 150 DPI for fine print or detailed drawings and 200 DPI if the file may be printed; 72 DPI gives the smallest files but blurs small text. Quality below about 40% produces visible JPEG artifacts around letters. Each page becomes one image, so the final size grows with the page count. If a born-digital PDF (created from Word or a web page) gets bigger in Strong mode, that is expected — vector text is already compact — and the smaller version is kept.
Privacy and limits
Nothing is uploaded: both libraries run in your browser, so you can compress contracts, pay stubs or ID scans without sending them to a server. If no mode makes the file smaller, the tool says so and offers the original unchanged. Password-protected PDFs can’t be processed; remove the password first.
Frequently asked questions
How do I make a PDF smaller for email?
Use Strong mode and lower the resolution to 100 or 72 DPI and the quality to 50–60%. If the result is still too large, try again with lower settings or split the document first.
Will compressing reduce the quality?
Lossless mode does not change quality at all. Strong mode does, because pages become JPEG images — check the result before deleting the original.
Why is my PDF not getting smaller?
It is probably already optimized, or it consists of vector text, which is more compact than images. Lossless re-saving has little to gain on such files.
Is it safe to compress confidential PDFs here?
Yes. The file is processed locally in your browser and is never uploaded to a server.
Not happy with the results?
Talk to Webin Agency about fast, SEO-friendly websites, e-commerce and Google Ads management.