How to compress a PDF online for free
Making a PDF smaller takes less than a minute. Follow these four steps to compress a PDF online without installing any software.
- 1
Select your PDF
Click “Select PDF file” or drag and drop a document into the box above.
- 2
Choose a compression level
Pick Extreme, Recommended or Basic depending on how small you need the file to be.
- 3
Click Compress PDF
Your browser reduces the PDF size in seconds. A progress bar shows each page as it finishes.
- 4
Download your smaller PDF
Check the before and after size, then download the compressed file. Nothing is stored anywhere.
Shrink PDF size, keep it readable
Large PDFs are a daily headache. They bounce back from email, fail on application portals and fill up your phone. Our PDF compressor reduces file size by optimizing the images that take up most of the space, so your document stays easy to read while the file gets far lighter.
Private by design
Compression runs locally in your browser. Your PDF is never uploaded, stored or shared.
Fast and simple
No installation, no account and no learning curve. Upload, compress and download.
Honest results
We show the before and after size. If we cannot improve a file, we say so and keep your original.
Choose the right PDF compression level
Every document is different, so you decide the balance between quality and size.
| Level | Best for | What you get |
|---|---|---|
| Extreme compression | Strict upload limits, email attachments, large scans | Smallest file and lower image quality. If needed, pages are converted to images |
| Recommended compression | Most documents, reports, brochures, CVs | Big size reduction with good on-screen quality. Text stays sharp and selectable |
| Basic compression | PDFs you want left almost exactly as they are | Only tidies the file structure, so savings are small |
How to compress a PDF to 100 KB, 500 KB or 1 MB
Many email services and online forms cap attachments at 1 MB, 2 MB or even 100 KB. To get under a limit, follow this simple routine:
- Run your original PDF through Recommended compression first and check the new size.
- Still too big? Compress the original again with Extreme compression. Avoid compressing an already compressed file repeatedly, because quality drops each time.
- For multi-page documents, remove pages you do not need before compressing. Fewer pages means a smaller file.
- Photo-heavy PDFs have the most to gain. Plain text PDFs are often small already.
When should you compress a PDF?
Email attachments
Get large reports and presentations under the attachment limit so they actually arrive.
Resumes and applications
Job portals and university forms often limit uploads. Compress your CV or documents to fit.
Scanned documents
Scans from a phone or office scanner are often huge. Reduce a scanned PDF’s size without retyping anything.
Storage and backups
Free up space on your phone, laptop or cloud drive by shrinking old PDFs.
Posters and brochures
Print-ready files full of images can be shrunk for easy sharing on screen and on the web.
Faster websites
Smaller PDFs download faster for visitors, which helps pages load quickly on mobile networks.
How does PDF compression work?
A PDF stores text, fonts, vector shapes and images. In most files the images are what make the document heavy. PDF compression lowers the resolution and quality of those images to a level that still looks good on screen, and trims data that is not needed, such as extra metadata. Because all of this happens on your own device, the process is fast and private.
Tips for smaller PDFs from the start
- Scan at 150 to 200 DPI instead of 600 DPI. It is plenty for reading.
- Export from Word, Google Docs or Canva using the “smallest size” or “web” option.
- Insert photos at the size you need rather than shrinking them in the document.
- Remove unused pages, attachments and embedded media before saving as PDF.
Compress PDF: frequently asked questions
Is the Apix PDF Tools compressor really free?
Yes. You can compress PDF files online for free, with no account, no watermark and no daily limit. It is free to use.
Is it safe to compress a confidential PDF?
Your file is compressed inside your own browser, so it is never uploaded to our servers or anyone else’s. That makes it a good fit for contracts, CVs, invoices and other private documents.
Can I compress a PDF without losing quality?
In most cases, yes where it matters. Recommended compression leaves your text and vector graphics exactly as they are and only shrinks the images inside the PDF, with a small drop in image sharpness that is usually hard to notice on screen. Basic compression changes nothing visible but saves less. Extreme compression trades more image quality for the smallest file.
How do I compress a PDF to 100 KB, 500 KB or 1 MB?
Start with Recommended compression and check the size. If the file is still over your limit, run the original again with Extreme compression. The final size depends on how many pages the PDF has and how image-heavy they are, so a 3-page text document will land far lower than a 60-page photo brochure.
Why can’t I select text in my compressed PDF?
Recommended compression keeps text selectable. Only when Extreme compression cannot reach a small enough size does it convert pages to images, and we tell you when that happens. If you need to copy or search the text, use Recommended or Basic compression.
How do I reduce the size of a scanned PDF?
Scanned PDFs are already made of page images, so they shrink very well. Choose Recommended compression for a clean, readable result, or Extreme if you need the smallest file possible for an upload form.
Why didn’t my PDF get smaller?
Some PDFs are already well optimized, and re-saving them can make them larger. When that happens we tell you and keep your original file instead of giving you a bigger one. Try Extreme compression for another attempt.
Can I compress PDFs on my phone?
Yes. The compressor works in modern mobile browsers on Android and iPhone. For the best results with very large files, use a desktop or laptop, because processing happens on your device.
What is the maximum PDF size I can compress?
You can compress PDFs up to 100 MB. Larger files can run out of memory in a browser, so we set this limit to keep things reliable.
Can I compress a password-protected PDF?
Not directly. Remove the password in your PDF viewer first, then compress the unlocked copy.
More free PDF tools are coming
We are adding merge, split and PDF to Word step by step. See everything in one place.
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