Free Compress PDF Online (Reduce PDF Size)
Shrink heavy scanned PDFs by rasterizing pages to compressed images at a quality you pick — a 12 MB scan can drop under 3 MB. Your file never leaves the browser.
When to use it
- Getting a multi-page scanned contract under an email or upload size limit.
- Shrinking a photo-heavy slide export before sharing it in a chat.
- Reducing a scanned receipt or ID bundle so it fits a portal's attachment cap.
- Making an image-heavy report lighter to store or send without splitting it.
About Compress PDF
Compress PDF shrinks a PDF by rendering each page to a compressed JPEG image at a quality level you choose, then rebuilding the file from those images. That approach delivers the biggest savings on scanned documents and image-heavy decks, where the original pages are large bitmaps. The trade-off is that the rebuilt pages are pictures, so any text they contained is no longer selectable or searchable — you are choosing a smaller, email-friendly file over an editable one.
How to use this tool
- Upload a PDF file.
- Choose the compression quality.
- Click Compress PDF.
- Download the smaller PDF.
Examples
12 MB scanned PDF (8 pages, photographed at high resolution)
2.8 MB PDF at medium quality — small enough to email as one attachment
Scanned pages are large bitmaps, so rasterizing at medium quality removes the most weight.
0.4 MB text-only PDF exported from a word processor
~0.4 MB (little or no reduction)
The pages are already crisp vector text, not images, so there is little to squeeze out.
Tips & gotchas
- This works best on scanned or image-heavy PDFs; a clean text-export PDF is already small and may not shrink.
- Pages are rasterized to images, so the resulting text is no longer selectable, searchable, or copyable.
- Start at medium quality and only drop lower if you still need a smaller file — low quality can blur fine print.
- If you only need to drop a few pages rather than recompress, splitting the PDF may save more than compressing.
Features
- Reduce PDF file size
- Adjustable quality
- Shows original vs compressed size
- Best for scanned / image-heavy PDFs
Specifications
| Input / output | PDF in, PDF out |
|---|---|
| Method | Pages rasterized to compressed JPEG images |
| Best for | Scanned and image-heavy PDFs |
| Trade-off | Text becomes non-selectable (rasterized) |
This tool runs in your browser. Your files and text are not uploaded to our servers, and we do not store your input.
Frequently asked questions
Why didn't my text PDF get smaller?+
Compression works by re-rendering pages as images, which helps scanned and image-heavy PDFs most. A PDF that is already crisp vector text is small to begin with and has little to remove.
Will the text still be selectable after compressing?+
No. Pages are rasterized to images, so selectable and searchable text is not preserved. Use this when a smaller file matters more than keeping text editable.
How much smaller will my file get?+
It depends on the source. A 12 MB high-resolution scan can drop to roughly 3 MB at medium quality, while an already-light text PDF may barely change.
Is my PDF uploaded to a server?+
No. The file is processed entirely in your browser, so it never leaves your device.
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