Compress PDF
Make a PDF of up to 50 MB smaller in your browser by saving its photos and scans again as compressed JPEGs. Free, no sign-up, and your file is not uploaded.
Drop a PDF here
or
One PDF at a time, up to 50 MB. Password-protected PDFs, and PDFs with editing or printing restrictions, can't be compressed.
Your PDF is compressed in your browser and is not uploaded.
Both modes write a new file, so a digital signature in the PDF will no longer be valid.
Add a PDF to compress.
How to Use Compress PDF
Add Your PDF
Drag a PDF onto the drop area or select Choose a PDF file. You can compress one PDF at a time, of up to 50 MB. The file is checked as it is added: password-protected PDFs, PDFs with editing or printing restrictions, and files that can't be read as a PDF are refused with a message.
Choose Normal or Strong
Normal keeps the text selectable and shrinks photos and scanned images. Strong turns every page into one image, which suits scans, but its text can no longer be selected or searched, and links, form fields and bookmarks are removed. Strong works on PDFs of up to 200 pages.
Pick an Image Quality
Low gives the smallest file (100 pixels per inch, JPEG quality 50), Medium is balanced (150 pixels per inch, JPEG quality 70) and High keeps images sharpest (200 pixels per inch, JPEG quality 85).
Compress and Download
Select Compress PDF. The work happens in your browser, so the time it takes depends on your device and the file. You then see the size before and after and the percentage saved, and you can download the copy, named after your file with -compressed added. If the copy isn't at least 1% smaller, your original file is kept and offered instead.
Key Features
Compressed in Your Browser
Your PDF is read and compressed on your own device with the open-source pdf-lib and PDF.js libraries. It is not uploaded to ToolistHub's server, so there is no upload to wait for and no copy of it on our side.
Normal Mode Keeps Your Text
Text, fonts and drawings are not changed, and links, bookmarks and form fields keep working. Photos and scanned images are saved again as JPEGs, at a lower resolution when they are well above the resolution you chose or larger than about 16 megapixels; data stored uncompressed is compressed without loss, and the file is saved in a more compact structure.
Strong Mode for Scans
Each page becomes one JPEG image at its original size and orientation (very large pages, such as posters, at a lower resolution), which can shrink scanned documents further. The text can no longer be selected, searched or read aloud by a screen reader, and links, form fields, bookmarks and attachments are removed. The title, author, subject and keywords are kept.
Results You Can Check
You see the size before and after and the percentage saved. Savings depend on the file: PDFs made mostly of photos or scans shrink the most, while a PDF that is mainly text may not get smaller. Every copy is opened again and its pages counted before it is offered.
Clear Limits
One PDF at a time, up to 50 MB, and up to 200 pages in Strong mode. Encrypted PDFs (password-protected, or with editing or printing restrictions) and damaged files are refused when you add them. In Normal mode some images are left as they are, for example CMYK images, greyscale images with a colour profile, palette (indexed) and 16-bit images, JPEG 2000 images, images with transparency, logos and charts that aren't stored as JPEGs, and 1-bit black-and-white scans.
Free, With No Sign-Up
Use it without an account or email address. No watermark is added, and because the compression runs in your browser, there is no hourly limit.
Common Use Cases
Email Attachments
Shrink a PDF that is too large to attach to an email, such as a report full of photos or a scanned contract. Check the new size shown after compressing: savings vary from file to file.
Upload Portals
Job, university and government portals often limit the size of uploads. Compress scanned certificates and forms to fit, then check that they are still easy to read.
Scanned Documents
Scanners often save pages at a high resolution. Normal mode lowers the resolution of many colour and greyscale scans and keeps any searchable text layer; Strong mode can shrink them further when you don't need to select the text.
Photo-Heavy Reports
Reports, brochures and portfolios often hold photos with far more detail than a screen shows. Medium or Low quality reduces that detail and the file size, while the text stays sharp in Normal mode.
Tips & Best Practices
- Start with Normal mode and Medium quality. If the file is still too large, try Low quality, then Strong mode.
- Use Strong mode for scans you only need to read or print. If you need to search, copy or fill in the PDF, use Normal mode.
- Check the compressed PDF before you send it, especially small print in photos and scans: a lower quality makes images softer.
- Compressing writes a new file, so a digital signature in the PDF will no longer be valid, and an archive copy made to the PDF/A standard may no longer meet it. Keep the original.
- Password-protected PDFs can't be compressed. If you can open the file, save an unprotected copy first (for example with print to PDF, when printing is allowed) and compress that copy.
Frequently Asked Questions
How do I compress a PDF?▼
Add a PDF with Choose a PDF file or by dropping it on the drop area, choose Normal or Strong and an image quality, then select Compress PDF. When it finishes, you see the size before and after and can download the compressed copy, named after your file with -compressed added.
Is my PDF uploaded to a server?▼
No. Compress PDF works in your browser with the open-source pdf-lib and PDF.js libraries, so your PDF is read and compressed on your own device and is not uploaded to ToolistHub's server.
What is the difference between Normal and Strong?▼
Normal keeps the PDF's text and structure and saves its photos and scanned images again as smaller JPEGs, so the text stays selectable and links, bookmarks and form fields keep working. Strong turns every page into one JPEG image: it can shrink scans further, but the text can no longer be selected or searched, and links, form fields, bookmarks and the text layer are removed. Strong mode works on PDFs of up to 200 pages.
How much smaller will my PDF get?▼
It depends on what is in the file. PDFs made mostly of photos or scans usually shrink the most; a PDF that is mainly text may not get smaller at all, because text already takes little space. You see the exact sizes and the percentage saved after compressing, and if the copy isn't at least 1% smaller, your original file is kept.
Will compressing reduce the quality?▼
Photos and scanned images can look softer, because they are saved again at a lower resolution and JPEG quality: Low gives the smallest file and High the sharpest images. In Normal mode, text and drawings are not changed. In Strong mode, the text becomes part of the page image, so it is only as sharp as the resolution you chose.
What are the limits?▼
One PDF at a time, up to 50 MB, and up to 200 pages in Strong mode. Password-protected PDFs, and PDFs that open without a password but restrict editing or printing, can't be compressed. In Normal mode, some images are left as they are, for example CMYK images, greyscale images with a colour profile, palette (indexed) and 16-bit images, JPEG 2000 images, images with transparency, logos and charts that aren't stored as JPEGs, and 1-bit black-and-white scans.
Is Compress PDF free?▼
Yes. It is free, needs no account and adds no watermark. Because it runs in your browser, there is no hourly limit on how often you can use it.