Reduce a PDF's file size by re-encoding its embedded images at a quality you choose and stripping unused objects. We show you the honest before-and-after size so you can decide if the trade-off is worth it. How much you save depends entirely on your document: image-heavy scans shrink dramatically, while text-only PDFs barely change. It all runs in your browser — no upload required.
Add your PDF
Drop the PDF you want to shrink onto the page, or click to browse. Files up to 100 MB are supported and processed locally.
Set the image quality
Drag the quality slider. Lower quality means smaller files but softer images; around 60% is a good balance for most documents with photos or scans.
Compress
Click Compress PDF. Your browser re-encodes embedded raster images to JPEG at your chosen quality and rewrites the file with tighter object packing.
Check the result and download
The result shows the new size and the exact percentage saved versus the original. If the savings aren't worth it, adjust the slider and try again before downloading.
It depends entirely on what's inside. PDFs dominated by high-resolution photos or scanned pages can shrink by half or more, while documents that are mostly text or vector graphics may only drop a few percent. We deliberately show the real before/after size rather than promising a fixed ratio, because miracle numbers would be dishonest.
No. Compression happens entirely in your browser using WebAssembly image codecs. Your PDF is never sent to a server, so you can safely compress private documents. Server-based competitors receive a full copy of your file; ConvertOwl never does.
Compression here works by re-encoding embedded images. A PDF that's mostly selectable text or vector graphics has little image data to shrink, so the savings are small. That's expected — there simply isn't much to compress in a text document, and we won't pretend otherwise.
Only the embedded images are affected, and only as much as the quality slider allows. Text and vector elements stay perfectly crisp because they're never rasterized. At moderate quality settings, image softening is usually hard to notice at normal viewing sizes.
It also rewrites the file using object streams, which packs the internal structure more tightly and drops unused padding. This gives a modest additional reduction on top of image re-encoding without altering how your document looks or reads.
Then your PDF was already efficient, and we show you that honestly so you can keep the original. You lose nothing by trying — the comparison runs locally and instantly, and you only download if the result is worthwhile.
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