Compress PDF Online

Shrink your PDF's file size for easier sharing by email or cloud storage. PDFDistrict rebuilds the PDF structure to remove redundant data, then shows you the before/after size so you can decide whether to download.

See before & after file size instantly
Never touches the quality of your images or text
Results depend on how the file was created
Processed entirely on your device

How PDF compression works

PDFDistrict Compress rebuilds your PDF's internal structure to remove redundant data left over from edits and revisions — it does not recompress or resample the images or text inside the file. How much smaller the result is depends entirely on what's already in the file: a document that's been edited and resaved several times often shrinks noticeably, while a file that's already well-optimized, or one made mostly of scanned images, may barely change. You'll see the exact before-and-after size before deciding whether to keep it — if it doesn't help, just discard the result.

Runs entirely in your browser — files aren't uploaded anywhere. Privacy →

Wondering which PDFs compress well and what to try when yours barely shrinks? Our guide to compressing a PDF covers both.

Practical use cases

A document that's grown noticeably in size after many rounds of edits in Word or Acrobat, before attaching it to an email.
Sharing a file through a channel with an attachment size limit, where every megabyte counts.

What actually changes during compression

PDFDistrict reloads the file and re-saves it using a more compact internal container format (object streams), which removes duplicate or orphaned internal bookkeeping left over from a document's edit history. It does not touch the images or text streams themselves — nothing is resampled, requantized, or re-encoded. That's why the result depends entirely on what was already inside the file: a document with a long edit history often shrinks noticeably, while a file made mostly of scanned images barely changes, because the images — the bulk of its size — are exactly the part this tool leaves alone. You always see the real, measured before-and-after size before deciding whether to keep the result; if it's the same size or larger, PDFDistrict says so plainly instead of showing a fake percentage.

If your real goal is a much smaller file and you don't need it to stay a searchable, editable PDF, converting it to images with PDF → JPG will usually shrink an image-heavy document far more than structural compression can — at the cost of no longer being a real PDF with selectable text.

Common problems

The file barely changed: that's expected for scanned or already-optimized PDFs — this tool doesn't recompress images, so it has little left to remove.
You compressed it twice and the second time did nothing: once the redundant data is gone, running Compress again has nothing left to save — that's a sign the file is already as small as this method can make it.
The file won't load at all: a password-protected or corrupted PDF shows "This file is password protected" or "This file appears to be corrupted or is not a valid PDF" instead of processing.

PDFDistrict vs. tools that upload your file

	PDFDistrict	Tools that upload your file
Sends your file to a server	No — processed in your browser	Yes, by design
Account required	No	Depends on the service
File size limit	100 MB per file, checked in your browser	Set by each service

Last updated: October 2026

Compress PDF — frequently asked questions

Why did my file size barely change? +

That usually means the file was already well-optimized, or it's dominated by image data that this tool doesn't recompress. It's an expected outcome, not an error — you can simply discard the result.

Does Compress reduce image or text quality? +

No. It never touches the images or text inside your file — it only removes redundant structural data, so visual quality is completely unaffected.

Will running Compress again reduce the size further? +

Usually not. Once the redundant structural data is removed on the first pass, there's typically nothing left for a second pass to clean up.

Can I compress a PDF without losing quality? +

PDFDistrict Compress does not recompress or resample images or text, so the pages look exactly the same. The trade-off is that the reduction depends on what is inside: files that were edited and resaved shrink the most, while scanned documents may barely change. You see the exact before-and-after size before deciding.

How do I compress a PDF to send it by email? +

Compress it, check the before-and-after size and download the result if it fits your email limit. If it is still too big, split the file or delete pages you do not need.