Runs entirely in your browser
Compress PDF files
Shrink large PDFs down to a smaller file size on your device — nothing is uploaded to a server. Drop one or more PDF files, pick a compression level, and download the result.
Drag & drop PDF files here
or use the button below · multiple files supported · .pdf only
MAX 50MB PER FILE · PASSWORD-PROTECTED PDFs ARE NOT SUPPORTED, REMOVE THE PASSWORD FIRST
What Is Compress PDF?
Compressing a PDF means reducing its file size so it's faster to email, upload, or store, without needing to delete any pages. Most of the size in a typical PDF comes from the images inside it — scanned pages, photos, or screenshots — so shrinking those images down is usually what makes the biggest difference.
This tool reads your PDF directly in your browser, rebuilds it at a smaller size using the compression level you choose, and hands you back a new file — without uploading anything to a server.
Why Use Our Compress PDF Tool?
Most online compressors ask you to upload your file to a remote server, wait in a queue, and trust that it's deleted afterward. This tool takes a different approach: reading the PDF and rebuilding a smaller version both happen inside your own browser tab using JavaScript libraries. Your document never leaves your device.
- No account or sign-up: open the page and start compressing immediately.
- No file uploads: nothing is transmitted to a server for processing.
- No paid API: compression runs on free, open client-side libraries.
- No hidden limits: compress as many PDFs as you like.
Key Features of Our Compress PDF Tool
Adjustable compression levels
Choose Light, Balanced, or Maximum compression depending on how much you're willing to trade sharpness for file size.
Lossless mode
Keep pages exactly as they are, with fully selectable and searchable text, for a smaller — if more modest — reduction.
Automatic best-result fallback
If compression wouldn't actually make your file smaller, the tool keeps the original instead of handing you a bigger download.
Before/after size comparison
See the original size, the new size, and the percentage saved for every file, right in the queue.
Batch processing
Queue up several PDFs and compress them all in one pass, each with its own result.
Automatic ZIP bundling
Compressing more than one file at once automatically packages the results into a single .zip download.
Benefits of Using Compress PDF
- Fit under email limits: shrink attachments that are too large to send.
- Stay private: in-browser processing means your documents never touch a third-party server.
- Save storage space: keep more documents without running out of room.
- Faster uploads and downloads: smaller files move faster over slow connections.
- No software to install: everything runs in the browser you already have open.
How to Use Compress PDF?
- Add your PDF. Drag and drop one or more PDF files onto the drop area, or click "Browse files" to select them.
- Choose a compression level. Pick Light, Balanced, Maximum, or Lossless depending on your priorities.
- Click "Compress PDF." Each file is rebuilt at a smaller size entirely on your device.
- Check the savings. The before-and-after size and percentage saved appear next to each file.
- Download your results. Use the download button in the summary window that appears — a single PDF, or a .zip if you compressed more than one.
Supported File Formats
| Format | Direction | Notes |
|---|---|---|
| PDF (.pdf) | Input | Standard, unencrypted PDF files. |
| PDF (.pdf) | Output | A rebuilt, smaller version of your original PDF. |
| ZIP (.zip) | Output | Automatically offered whenever more than one file is compressed at once. |
Why Choose Our Online PDF Tool?
There's no shortage of PDF compressors online, but many route your file through a server, require a paid plan, or limit how many files you can compress per day. This tool is built around a simpler premise: compress entirely on your device using free, open libraries — no paid conversion API involved — and stay free to use without a login.
Privacy and Security
Because compression happens client-side, your PDF is read directly into your browser's memory, rebuilt there, and written back out as a new file — at no point is the file content sent to a server operated by this site or anyone else.
Common Use Cases
- Shrinking scanned documents so a multi-page scan fits under an email attachment limit.
- Preparing files for a website or portal that caps upload sizes.
- Archiving reports to save space without losing pages.
- Speeding up sharing over a slow or metered connection.
Frequently Asked Questions
Is this Compress PDF tool really free?
Yes. There's no sign-up, no per-file fee, and no watermark added to the compressed files.
Are my files uploaded to a server?
No. Reading the PDF and rebuilding a smaller version both run inside your browser using JavaScript. Your document is never transmitted anywhere for processing.
Will compressing reduce the quality of my PDF?
With Light, Balanced, or Maximum compression, each page is redrawn as a compressed image, so very fine text or line art can look slightly softer and the text is no longer selectable or searchable. If keeping the original text intact matters more than file size, use Lossless mode instead — it keeps every page exactly as it was, usually with a smaller reduction in size.
What's the difference between the compression levels?
Light, Balanced, and Maximum trade image sharpness for file size — Maximum gives the smallest file but the softest images. Lossless skips that trade-off entirely by keeping pages as vector text and graphics; it works best on PDFs that already contain few or no large images.
Can it compress password-protected PDFs?
No. Files that require a password to open are not supported — remove the password with a PDF unlock tool first, then compress the result.
What happens if compression doesn't actually shrink the file?
If the rebuilt file would end up larger than your original — common with PDFs that are already small or text-only — the tool keeps your original file instead, so you never end up with a bigger download.
Is there a limit to how many files I can compress?
No hard limit is enforced by this tool. The practical limits are your device's memory and the 50MB-per-file size cap, which keeps in-browser processing responsive.
Conclusion
Shrinking a PDF shouldn't require uploading sensitive pages to an unknown server or installing desktop software. This tool aims to make compressing fast, private, and free — reading and rebuilding your document entirely on your own device, from a single quick file to a full batch.