Compress PDF Online (100% Free & Private)
Shrink a PDF with a lossless clean-up or by re-rendering pages at a lower image quality, with real before and after sizes.
PDF Compressor
Shrinks a PDF in your browser and shows the real before and after size. 100% client-side; nothing is uploaded.
Large files work, but very long documents take a while on phones.
What this tool does and who it is for
Compress PDF shrinks one PDF at a time inside your browser and shows the real size before and after. Nothing is uploaded. You choose between two honest methods, because no single trick works on every file.
Lossless clean-up reloads the file and writes it back with compressed object streams, and removes the document metadata (the Info fields such as title and author, plus the embedded XMP packet). Text, fonts and images are left exactly as they were, so savings are usually modest.
Reduce image quality (rasterize) renders every page to a JPEG at 100, 150 or 200 dpi with the quality you pick, then rebuilds the PDF at the original page sizes. This is what shrinks scans and photo-heavy files, but the text becomes part of a picture: it can no longer be selected, searched or copied. If either method produces a file that is not smaller, the tool tells you and hands back your original.
Official Formula / Technical Standard
Real-World Worked Scenario
Select your PDF documents, apply the desired operation, and save the updated file directly to your local storage.
When people use it
Get a phone scan under an upload limit
A multi-page scan of a lease or medical form is mostly image data. Rasterizing at 150 dpi with medium quality usually brings it down sharply while staying readable.
Scrub author details before sharing
Lossless clean-up removes the title, author and XMP metadata so a resume or proposal does not carry the name of whoever built the template.
Trim exports from office software
Some programs save PDFs with loose internal structure. A lossless re-save can trim a little with no visual change, and the text stays searchable.
Notes for US users
- Many US upload portals state a maximum size in megabytes. Check the number on the portal itself, then compare it with the compressed size shown here before you submit.
- For forms and statements, 150 dpi is usually readable on screen and 200 dpi prints cleanly, but confirm the requirements of whoever receives the file.
- Some e-filing systems require text-searchable PDFs. Rasterized output is not searchable, so use lossless clean-up (or run OCR afterwards) for those portals.
- Wiping metadata is handy for privacy, but it does not remove visible content. Names inside the page text and images stay.
Limits and what to double-check
- •Lossless clean-up does not touch images, so scan-heavy PDFs barely shrink with it. Some files come out the same size or larger; in that case you get your original back.
- •Rasterizing turns each page into a JPEG. Text is no longer selectable or searchable, and links, form fields, bookmarks, annotations and digital signatures are dropped.
- •Password-protected PDFs must be unlocked first. One file is processed at a time, and very long documents can be slow or run out of memory on phones.
Expert Best Practices & Common Pitfalls
Recommended Best Practices
- •Keep local backup copies of original PDF files before applying irreversible transformations.
- •Check document formatting and page orientations after processing.
- •Ensure source PDFs are not corrupted before combining or splitting.
Common Mistakes to Avoid
- •Uploading confidential tax filings or contracts to unknown third-party cloud servers.
- •Attempting to process password-protected files without first unlocking them.
- •Ignoring file size limits on target email or portal destinations.
Features & Security Architecture
- 100% Client-Side: Zero server uploads ensure complete privacy and data confidentiality
- Fast Results: Processing happens on your own device, so there is no upload or server queue to wait for
- No Sign-Up Required: Completely free to use with no daily usage caps or account requirements
- Works on All Devices: Fully responsive across desktop, tablet, and mobile browsers
Frequently Asked Questions
How does the Compress PDF work?▼
The Compress PDF runs 100% inside your web browser using modern client-side JavaScript. It performs calculations, conversions, and document processing locally on your device without sending any data to external servers.
Is this compress pdf completely free to use?▼
Yes. This tool is completely free with no usage limits, no subscriptions, and no registration required.
Is my data private when using the Compress PDF?▼
Yes. Because all operations execute locally on your computer or phone, your inputs, documents, and data never leave your browser.
Which method should I use?▼
Try lossless clean-up first if the PDF came from Word or another program and you need the text to stay searchable. Use rasterize for scans, photo-heavy files, or when you must hit a size limit and searchable text does not matter.
Why did lossless clean-up barely change the size?▼
Because images dominate most large PDFs and lossless mode leaves them alone. It only repacks the internal structure and removes metadata. A text-based export may drop a little; a scanned contract will land close to its original size.
What happens if the result is bigger than my original?▼
The tool compares the sizes after processing. If the new file is not smaller, it says so and the download button gives you your original file, unchanged. A PDF that was already well optimized, or a rasterize setting higher than the source images, can cause this.
Will rasterizing make my text blurry?▼
At 100 dpi small print can look soft, especially when zoomed in. 150 dpi is a reasonable middle ground and 200 dpi is close to the original on paper. Lower JPEG quality adds visible artifacts around text, so raise it if the downloaded file looks rough.
Does compressing break digital signatures?▼
Yes, any re-save can invalidate a certificate-based signature, and rasterizing removes it entirely. Compress before a document is signed, not after.