Free · no signup · nothing uploaded
Compress PDF
Shrink a PDF's file size with a quality-preserving pass, right in your browser — you'll see the before/after size before you download.
Choose a PDF to compress
or drop your file here.
Runs in your browser — your file is never uploaded.
Short answer
To compress a PDF, choose your file and it's re-optimized in your browser — you'll see the before and after size. It never makes the file bigger, keeps text and images intact, and nothing is uploaded. Free and fully in-browser.
Compress PDF guides
How to compress a PDF
- 1Open the tool. Open the Compress PDF tool — no signup or install.
- 2Choose your PDF. Drag it in or click to select.
- 3Compress. The file is re-optimized in your browser and you'll see the before/after size.
- 4Download. Download the smaller PDF — nothing was uploaded.
What actually shrinks when you compress a PDF
| What's in your PDF | Typical saving | Why |
|---|---|---|
| Scanned pages (photos of paper) | Large | Big images re-encode to a lower quality |
| Photo-heavy brochures | Large | Images dominate the file size |
| Mixed text and images | Moderate | Only the image portion can shrink |
| Text-only documents | Small | Text and fonts are already tightly compressed |
| Already-compressed PDFs | Little or none | There is no redundancy left to remove |
| Vector diagrams & charts | Little or none | Vectors are instructions, not pixels |
Compression works almost entirely on embedded images, so a PDF's make-up decides the result far more than any setting. A text-only file that barely shrinks is not a failure — it means it was already efficient.
Frequently asked questions
Is my PDF uploaded to compress it?+
No. The PDF is re-optimized entirely in your browser and never sent to a server — safe for private files and works offline once loaded.
How much smaller will my PDF get?+
It depends on the file. PDFs bloated with redundant structure or exported inefficiently can shrink noticeably; already-optimized or plain-text PDFs may shrink little. The tool always returns whichever is smaller — original or compressed — so it never makes your file bigger.
Will compressing reduce quality?+
The in-browser lossless pass (restructuring the file) keeps text and images identical. It's a safe, quality-preserving optimization rather than aggressive down-sampling.
Why didn't my PDF get much smaller?+
If it's mostly text or was already optimized, there's little redundant data to remove. The biggest savings come from PDFs with bloated internal structure.
Is it free?+
Yes — no signup, no watermark, and it runs entirely in your browser.
Related tools
Your PDF is compressed entirely in your browser and is never uploaded. The lossless pass preserves content; savings vary by file. Provided free and ad-supported, without warranty.