PDF Compressor
Make a PDF smaller using one of two honest methods. “Optimise structure” re-saves the file with a more compact internal layout and keeps text selectable, but typically saves little. “Rasterise pages” turns each page into a JPEG picture for large savings on image-heavy files, at the cost of text you can select or search.
Compress a PDF
Your files are processed in your browser and are not uploaded. Only use documents you are authorised to process. Compression results depend heavily on what the PDF contains; the tool shows the real result and never claims a saving that did not happen.
About the selected method
Compression result
Your download
How to Use the PDF Compressor
- Choose your PDF.
- Read the explanation and choose a method. Start with Optimise structure; if the result is not small enough, try Rasterise pages.
- For rasterising, pick a resolution (DPI) and JPEG quality. Lower values make smaller files.
- Press Compress. Compare the original and new size and download the new file only if it is really smaller.
About This Tool
People who hit an email attachment or upload size limit and need a smaller file, and who want to know exactly what they are trading away to get it.
Input: PDF · Output: PDF.
Features and Limitations
Features
- Shows the original size, new size and percentage saved.
- If the output is not smaller, it says so and offers your original file back instead of a bigger one.
- Rasterise mode caps the picture size per page to protect your browser from running out of memory.
- Nothing is uploaded.
Limitations
- The in-browser library cannot re-compress images already inside a PDF. Optimise structure therefore only removes overhead: savings are usually modest (often under 10%), larger mainly for small files saved without compact object storage, and some files will not shrink at all.
- Rasterised PDFs lose selectable and searchable text, links, bookmarks and form fields; pages become flat pictures. Do not use it on documents that must stay searchable or accessible.
- Rebuilding from pages removes bookmarks, form fields and tagged-PDF structure.
- Password-protected PDFs must be unlocked first.
- Processing happens on your device, so very large files depend on your browser's available memory.
Example
In our own test, a 4-page, 15 MB photo-heavy PDF fell to about 0.37 MB (97% smaller) when rasterised at 110 dpi and 70% quality, but its text was no longer selectable. Optimising the structure of the same file saved only 1.5 KB.
Frequently Asked Questions
Why did my PDF not get smaller?
Optimise structure can only remove overhead; if your PDF is already compact, or its size comes from large images, there is little to remove. Try the rasterise method, accepting that text will no longer be selectable.
Will the text still be searchable after compressing?
After Optimise structure, yes. After Rasterise pages, no: every page becomes a picture, so you cannot select, copy or search the text and screen readers cannot read it.
What DPI and quality should I choose?
For reading on screen, 100-120 dpi at 60-75% quality is a good balance. For documents that will be printed, use 150-200 dpi and 80% or more.
Are my PDFs uploaded to a server?
No. The work is done by JavaScript libraries running inside your browser tab, so the file never leaves your device. Closing the tab discards everything.
Can I process a password-protected PDF?
Not directly. Browsers cannot open encrypted PDFs without the password, so the tool stops with a clear message naming the file. Remove the password first with our PDF Unlock Utility (you need to know the password and be allowed to remove it), then come back.
Related Tools
More like this: all PDF Tools tools, all Files & Documents tools or the TinySandy home page.