Compress PDF
Reduce the file size of a PDF without losing readable quality. Choose a compression level, preview the size reduction, and download — all in your browser. No upload, no signup, no watermark.
Drop a PDF file here
or click to select from your device
Max 50 MB · Format: .pdf
How to Compress a PDF
- Drop a PDF file onto the upload area.
- Choose a compression level and image quality.
- Click "Compress PDF" — the file is processed in your browser.
- Click "Download Compressed PDF" to save the smaller file.
Why Your Files Stay Private
The compression runs entirely in your browser. No PDF is uploaded to a server, stored, logged, or shared. Unlike most online PDF compressors, your document never leaves your device. You can disconnect from the internet after the page loads and the compressor will still work.
How PDF Compression Works
A PDF is a container for text, images, fonts, and structural metadata. The size comes primarily from embedded images — a scanned document is mostly images, while a text-based PDF is mostly fonts and text.
This tool re-encodes the PDF by:
- Re-sampling images at a lower quality (controlled by the quality slider)
- Removing redundant metadata
- Optimizing the PDF structure
Text-based PDFs compress less because the text is already efficient. Scanned PDFs (images) compress dramatically — often 50–80% reduction. The "Saved" figure in the result box tells you exactly how much this file shrank.
Frequently Asked Questions
Is this PDF compressor free?
Yes — completely free, no signup, no watermark, no file limit. The compression runs in your browser, so there is no server cost per document. Compress as many PDFs as you need.
Does compressing reduce PDF quality?
It depends on the file. Text-based PDFs lose almost nothing — text is stored as text, not as images, so quality is preserved. Scanned PDFs (images) lose some detail when re-encoded at lower quality. At the "Recommended" level (60%), the difference is usually unnoticeable for reading. At "Strong" (40–50%), you may see softness in images, but text remains readable.
Why does my PDF barely shrink?
Text-based PDFs (Word exports, digital signatures, forms) are already efficient — there is little to remove. If your PDF is mostly text, expect 10–30% reduction. If it is a scanned document or contains large images, expect 50–80% reduction. The tool shows the actual savings after compression, so you can decide whether the result is useful.
Is there a file size limit?
The tool accepts PDFs up to 50 MB. Larger files may cause the browser to run out of memory during compression. For PDFs over 50 MB, use a desktop tool like Ghostscript or Adobe Acrobat Pro.
Does this work on mobile?
Yes — the tool runs in any modern mobile browser. You can select a PDF, choose compression settings, and download the compressed file. For very large PDFs, use a desktop browser for better performance.
What about password-protected PDFs?
Password-protected PDFs cannot be compressed without first removing the password. Decrypt the file in your PDF reader, then compress. The tool will alert you if a file cannot be processed.