Compress PDF
Reduce PDF file size
Note: Pages are converted to images. Text becomes non-selectable but file size drops significantly. Use "High quality" for text-heavy PDFs.
How it works
Compress PDF — Reduce PDF file size. All processing happens in your browser — no upload, no signup, no email required. Free forever.
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About Compress PDF
Compress PDF reduces the file size of a PDF — often by 50% to 90% — so you can attach it to an email, upload it to a portal with strict size limits, or simply store it more efficiently. The PDF compressor runs entirely inside your browser, with no upload step.
It works by rendering each page to an image at a chosen quality and reassembling them into a new PDF. That trade-off makes it ideal for image-heavy documents, scanned papers, brochures, and photo books, while text-only PDFs sometimes benefit less.
Because the original file never leaves your computer, you can shrink confidential documents (passports, ID copies, signed contracts) without worrying about a service operator seeing them.
How to use Compress PDF
- Drop your PDF onto the upload zone — the tool reads it locally without sending anything over the network.
- Pick a quality preset: High quality keeps text crisp at modest savings, Balanced is good for everyday email attachments, and Maximum produces the smallest possible file.
- Click Compress and watch the progress as each page is rendered, optimised, and re-embedded.
- Once done, you'll see the original size, the compressed size, and the percentage saved.
- Download the smaller PDF; the original on disk is left untouched so you can re-compress with a different setting if needed.
Common use cases
- Squeezing a 30 MB scanned contract under the typical 10 MB email attachment limit.
- Shrinking a photo-heavy brochure or pitch deck before uploading it to a job portal that caps file size at 5 MB.
- Reducing the storage footprint of a document archive on a NAS or cloud drive without losing any pages.
- Preparing a PDF for fast download on a public website where every megabyte affects load time.
- Compressing high-resolution scans from a multifunction printer that produces unnecessarily large files by default.
Tips & common mistakes
- Compression converts pages to images, which means text inside the PDF will no longer be selectable or searchable. If you need searchable text, choose High quality and run OCR afterwards.
- Already-compressed PDFs (those exported from web tools or cameras) may not shrink much further — physics catches up at some point.
- For text-heavy reports, sometimes the best PDF size reduction is to re-export the source document with image downsampling settings rather than re-compress the PDF.
- Very large PDFs (500 MB+) consume substantial browser memory while compressing; close other tabs and avoid switching apps until the operation finishes.
Frequently asked questions
How much can my PDF be compressed?
Image-heavy PDFs typically shrink 50-90%. Text-only PDFs may shrink less. Try the 'Maximum' preset for the smallest size.
Does compression affect text selection?
Yes — pages are converted to images, so text becomes non-selectable. Use 'High quality' if you need text-based PDFs.
Is there a maximum file size?
No upload limit. The browser does the work, so very large PDFs (500MB+) may consume significant memory.
Will compression damage scanned documents to the point of illegibility?
Balanced quality is generally fine for office paperwork at typical reading sizes. If your scan contains small fonts (footnotes, fine print, signatures), prefer High quality to keep the strokes sharp.
Can I batch-compress several PDFs at once?
Currently the tool processes one PDF at a time. For batches, compress them sequentially or use Merge PDF first and compress the combined file.
Why is my compressed PDF sometimes larger than the original?
If the source PDF stored its images very efficiently (or used vector text), re-rendering to images at a high quality can ironically increase size. Try a more aggressive preset or accept that this particular file is already optimal.