How to Compress a PDF Online
A large PDF can be too big to email or upload. This free Compress PDF tool shrinks the file so it fits within size limits, while letting you choose how much to compress. It runs entirely in your browser, so your document is never uploaded — important for anything private.
Add your PDF
Drop a PDF or click to browse. It's read locally on your device and the page count is shown instantly.
Choose a level
Pick Low, Medium, High or Extreme depending on how much smaller you need the file.
Compress and download
See how much you saved, then download the smaller PDF. Your original stays untouched.
Compression Levels Explained
Different levels trade quality for size in different ways — here's the honest breakdown:
Low — best quality
Strips hidden metadata and re-saves efficiently. Text stays fully selectable and pages look identical.
Medium — recommended
A balanced squeeze that keeps the document readable while noticeably reducing size. The best default for most files.
High — smaller
Flattens each page into a sharp image to cut size further. Great for sharing, but text is no longer selectable.
Extreme — smallest
Maximum shrink for tight upload limits. Pages become images, so use it when small size matters more than editing.
Text vs images
Honest note: High and Extreme rasterize pages, so you can't select or copy text afterwards. Choose Low or Medium to keep text.
Runs in your browser
All compression happens on your device — your PDF is never uploaded, so it's private and instant.
Free and 100% Private
Compressing a PDF often means handling private paperwork, so this tool keeps everything on your device. Your file is never uploaded, stored or seen by anyone. It's completely free, with no account, no daily cap and no watermark on the result.
Need to combine files first? Use Merge PDF. Want to break one apart? Try Split PDF, or shrink photos before making a PDF with Compress Image.
Compress PDF on Any Device
How to compress a PDF on Windows
Open this page in any browser, add your PDF, pick a level, and click Compress. You get a smaller PDF — no Acrobat or other software needed.
How to compress a PDF on Mac
Open the page in Safari or Chrome, add the PDF, choose a level, and download the smaller file. Everything runs locally, so it's fast and private.
How to compress a PDF on iPhone or Android
Open this page in your phone's browser, tap to pick the PDF from Files, choose a level, and save the smaller PDF to your device.
How to compress a PDF to a specific size
Try Medium first and check the result. If it's still too big, step up to High or Extreme — each shows the exact new size so you can compare.
How to compress a PDF for email
Most email limits are around 25 MB. Pick Medium or High until the compressed size fits comfortably under the limit.
How to compress a PDF without losing text
Use the Low or Medium level. These keep your text fully selectable while still reducing the file size.
Frequently Asked Questions
How do I compress a PDF for free?
Add a PDF above, choose a compression level, and click Compress. You get a smaller PDF in seconds — completely free, with no signup and no watermark.
Are my PDFs uploaded to a server?
No. Compression happens right inside your browser, so your file never leaves your device. Nothing is uploaded, stored or seen by anyone.
How much smaller will my PDF be?
It depends on the file and level. Text-heavy PDFs shrink less; image-heavy PDFs can drop dramatically. The tool shows the exact before-and-after size.
Will I lose quality?
Low and Medium keep quality high and text selectable. High and Extreme flatten pages to images for more shrink, so text becomes non-selectable.
Why can't I select text after compressing?
The High and Extreme levels turn each page into an image to save the most space. Use Low or Medium if you need selectable text.
What if my PDF is already small?
The tool will tell you if the file is already well optimized and couldn't be shrunk further without hurting quality.
Is there a page or file size limit?
There is no fixed limit. Very large PDFs just take a little longer since everything runs on your device.
Can I compress a password-protected PDF?
You'll need to remove the password first. Encrypted PDFs can't be read for compression until they're unlocked.
Does it work on mobile?
Yes. It runs in any mobile browser on iPhone and Android — add your PDF and download the smaller file.
Are my original files changed?
No. The tool creates a new compressed PDF and never modifies or deletes your original file.
Is this Compress PDF tool really free?
Completely free, with no account, no watermark, no limit and no premium wall.
100% private — your PDF is compressed right here in your browser and never uploaded to any server.
Last updated: July 2026 · FlipMyFormat Compress PDF
Written and maintained by the FlipMyFormat team