PDF converter
Compress PDF
Make PDF files smaller so they fit email and upload limits. Choose how strong the compression is and download a lighter PDF. Free, with no sign-up.
Tested by Thiago · Updated
Free, no sign-up · Sent over HTTPS · Files are deleted from our server automatically after 30 minutes
How to compress a PDF
- Add your files: drag them into the box above, or click "Choose files".
- Choose a compression level and click "Compress PDF".
- Download the smaller PDF. If your file is already well compressed, you get the original back. Files are removed from our server after 30 minutes.
When to compress a PDF
Email services, job portals and government websites often cap uploads at 2, 5 or 10 MB, and scanned documents or PDFs full of photos easily go over that. Compress PDF makes the file smaller mainly by reducing the resolution of the images inside it, while text and vector graphics stay sharp. Choose how strong the compression should be: the recommended level keeps documents perfectly readable at a fraction of the size.
- An email or upload form rejects your PDF because it is too big.
- A scanned document or a PDF made from phone photos is much heavier than it should be.
- You want to save storage space or make a PDF faster to download from your website.
What happens to a full-page photo at each level
To see what the levels really do, we made a PDF from three 12-megapixel phone photos, each filling a landscape A4 page, and compressed it with the same settings this page uses. The pictures inside, originally 4000 pixels wide, were rebuilt about 3040 pixels wide on Light, 1520 on Recommended and 730 on Strong.
At 1520 pixels a photo still looks sharp on a laptop screen and on a printed page. At 730 it looks fine on a phone but soft on a large monitor, and small print that was photographed on paper can become hard to read. That is why Strong is best kept for files that have to squeeze under a tight limit.
Best order of steps when preparing a document
- Fix the content first: remove extra pages with Split PDF and turn sideways pages with Rotate PDF.
- Combine the files with Merge PDF if the form wants a single document.
- Compress last, and only once. Each extra round makes the pictures inside a little softer.
- If the document needs a digital signature, sign after compressing, because compression rebuilds the file and a signature added earlier will show as invalid.
Tips for the best result
- Start with Recommended (150 dpi images). Use Strong only if the file is still too big, because photos inside the PDF will look softer.
- PDFs made mostly of text barely shrink, since text is already compact. The biggest savings come from scans and photos.
- If the compressed file would not be smaller, you get your original back, so you never end up with a bigger file.
- Password-protected PDFs cannot be compressed. Remove the password in your PDF reader first, if you are allowed to.
About these formats
PDF: The standard format for documents. It looks the same on every device, which makes it ideal for sharing, printing and sending scans.
Frequently asked questions
Will the text stay sharp?
Yes. Text and vector drawings are kept as they are, and only images are resampled to a lower resolution.
How much smaller will my PDF get?
It depends on the content. Scans and PDFs full of photos often shrink dramatically, while text-only PDFs change very little.
What is the difference between the levels?
Strong reduces images to 72 dpi (fine for screens), Recommended to 150 dpi (good for reading and printing at home) and Light to 300 dpi (high-quality printing).
Is it free and private?
Yes. It is free, with no sign-up. Your PDF is deleted from our server as soon as it is compressed, and the result after 30 minutes.
Can I compress a PDF to an exact size, like 1 MB?
There is no size target. The result depends on how many pictures the PDF contains and how large they are, so the same level can give 200 KB for one file and several megabytes for another. Pick a level, check the size and adjust from there.
Does Compress PDF work on a Mac, iPhone or Android?
Yes. The compression itself runs on our server, so it works the same from any current browser on a computer or phone. Only the upload and download depend on your connection speed.
Helpful guides
- How to Turn Phone Photos of Documents Into a Single PDF
- How to Merge PDF Files Into One (in the Right Order)
- How to Reduce a PDF File Size for Email and Upload Forms
- Email Attachment Too Large? How to Shrink Videos, PDFs and Photos to Fit
- How to Convert Word to PDF (Free, Even Without Microsoft Word)