PDF files are notorious for getting large. A presentation with high-resolution images can easily reach 30 MB or more — well above the attachment limits of most email clients and upload portals. Compressing a PDF reduces file size so it's easier to share, without making it visually worse.
MakeitPDF's Compress PDF tool analyses your file and applies smart compression automatically. Most PDFs shrink by 50–80% while remaining sharp on screen and in print.
Key takeaways
- Most PDFs can be compressed by 50–80% without noticeable quality loss.
- Compression works by optimising embedded images and removing redundant data.
- Text-only PDFs are already small — image-heavy files benefit most from compression.
- Free, no account, no software — works on any device.
Table of contents
Why PDFs get so large
PDFs grow large for a few predictable reasons. The biggest culprit is embedded images — when you export a presentation or scan a document, images are often stored at print resolution (300 DPI or higher) even when the PDF will only ever be viewed on screen. Screen viewing typically requires only 72–150 DPI.
Other contributors include embedded fonts (a PDF can embed an entire font family even if only a few glyphs are used), duplicate objects, and metadata left over from editing software.
PDF compression addresses all of these: images are downsampled to an appropriate resolution, fonts are subsetted, and redundant data is removed.
How to compress a PDF with MakeitPDF
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Go to the Compress PDF tool.
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Upload your PDF by clicking Select PDF or dragging the file into the upload area.
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The tool compresses your PDF automatically. Once processing is complete, you'll see the original and compressed file sizes.
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Click Download Compressed PDF to save the result.
Will compression affect quality?
For most PDFs, the visual difference between the original and the compressed version is imperceptible on screen and minimal in print. If a document will be printed at A3 or larger, you may want to preserve higher image resolution.
Text in PDFs is stored as vectors, not as pixels, so it is never affected by compression — it remains perfectly sharp at any zoom level no matter how aggressively you compress.
Tips for getting the smallest file
- Compress after merging. If you're combining multiple PDFs, merge them first, then compress the result in one pass.
- Remove unnecessary pages with the Remove Pages tool before compressing.
- Convert to grayscale if colour isn't needed — the Grayscale PDF tool can reduce file size further.
Frequently asked questions
My PDF barely got smaller — why?
PDFs that contain mostly text compress very little because the text is already efficiently encoded. Files that are already compressed (e.g., previously run through a compressor) also leave little room for further reduction.
Is online PDF compression secure?
Your file is transferred over an encrypted HTTPS connection, processed, and then deleted from our servers after your session. We do not store or access your documents.
Can I compress a password-protected PDF?
You'll need to remove the password first, compress the file, then re-apply password protection with the Protect PDF tool.
How small can a PDF get?
There is no fixed limit — it depends on the content. A 20 MB scan-heavy report might compress to 4 MB; a 5 MB text document might only reach 4.5 MB. The tool always shows you the before and after sizes.
