UlvixorPDF Compressor
Upload a heavy PDF — typically a scanned document or one full of photos — and shrink its file size by choosing a compression level. The tool regenerates every page as a compressed image, which works great for scans and photo-heavy documents, though the text stops being selectable. Everything happens in your browser with pdf.js.
How it works
- Select a PDF file from your device using the file picker.
- Choose the compression level: low (better quality), medium (recommended balance), or high (maximum size reduction).
- Each page is rendered as an image with pdf.js at the resolution matching the chosen level, then re-encoded as JPEG at that level's quality.
- The resulting images are combined into a new PDF, one image per page, keeping each page's original size.
- Download the compressed PDF and compare the original size against the new one.
Use cases
- Shrink a scanned PDF (for example, one captured with a phone camera) before emailing it.
- Compress a photo-heavy PDF, like a portfolio or catalog, to make it easier to share.
- Reduce a document's file size to meet a file-upload form's size limit.
- Compare how much a given PDF shrinks at different compression levels before picking the final one.
Use cases
- Shrink a scanned PDF (for example, one captured with a phone camera) before emailing it.
- Compress a photo-heavy PDF, like a portfolio or catalog, to make it easier to share.
- Reduce a document's file size to meet a file-upload form's size limit.
- Compare how much a given PDF shrinks at different compression levels before picking the final one.
Common mistakes
- Compressing a PDF that's already mostly text (for example, exported from Word) expecting it to shrink a lot more.This tool compresses by turning every page into an image, which helps enormously on scanned or photo-heavy PDFs, but may not shrink (or could even grow) a PDF that was already efficient because it's mostly vector text. In that case, the original PDF is already the lightest version possible.
- Expecting to be able to select or search text in the compressed PDF.The resulting PDF is made of images of each page, not real text, so you won't be able to select, copy, or search text in it. If you need to keep selectable text, use the Image Compressor on the photos before assembling the PDF instead of this tool.
- Using the highest compression level for a document where text readability really matters.The high level cuts resolution quite a bit and can make text blurry or hard to read, especially at small font sizes. Try the medium level first, and only increase compression if you need an even lighter file.
Frequently asked questions
No. The entire process, from reading the PDF to generating the compressed file, happens in your browser using the pdf.js and jsPDF libraries. Your file is never uploaded to any server.
This tool works by converting every page into a JPEG image, which greatly reduces the size of scanned PDFs or ones with high-resolution photos. But if your original PDF was mostly text (light per page), converting it to images may not shrink it, or could even make it bigger. In that case, the original PDF was already efficient.
Yes. The compressed PDF is made of one image per page, not real text, so you won't be able to select, copy, or search text in the result, though you can still view and print it normally.
The medium level offers the best balance for most cases. Use the low level if visual quality is the priority (for example, for printing), and the high level only when you need the smallest possible file and can accept lower quality.
Alternatives
Tools like Adobe Acrobat or online services like Smallpdf and iLovePDF compress PDFs with more sophisticated algorithms that can shrink internal images without turning the whole document into images. This tool is handy when you'd rather your document never leave your browser, especially for scans where selectable text isn't a priority.