How much can a PDF be compressed?
Compression savings depend heavily on the content type. Image-heavy PDFs (scanned documents, presentations with photos) compress dramatically — 60–80% savings are common. Text-only PDFs that already use efficient internal compression may only compress 10–30%.
| PDF Type | Typical Original Size | After Compression | Savings |
|---|---|---|---|
| Scanned certificate (1 page) | 2–5 MB | 300–600 KB | 70–85% |
| Resume with photo | 1–3 MB | 200–500 KB | 60–80% |
| Presentation (20 slides) | 10–30 MB | 2–6 MB | 70–80% |
| Scanned marksheet (4 pages) | 5–10 MB | 500KB–2 MB | 60–80% |
| Text-only report | 500KB–2 MB | 400KB–1.5 MB | 10–30% |
| eBook / novel (100+ pages) | 5–20 MB | 1–5 MB | 50–75% |
🔗 Related Tools on Aero Tools
Quality Level vs Target Size — which to use?
Quality Level is the faster option. Pick High Quality (30–50% savings), Balanced (50–70%), or Max Compression (65–80%). Best when you don't have a specific size requirement.
Target Size is for when you have an exact portal requirement — "must be under 500KB" or "must be under 1MB". The tool binary-searches quality and resolution settings automatically until it hits your target.
How to reduce PDF file size (3 steps)
Upload your PDF using Choose PDF or drag and drop. Any PDF — scanned, image-based, or text — up to any file size or page count.
Choose Balanced quality level for general use, or switch to Target Size mode and enter a specific size like 500KB or 1MB. Click Reduce PDF Size.
Preview the before/after size comparison and click Download. The tool shows you exactly how much was saved.
Frequently asked questions
Is this better than iLovePDF or Smallpdf?
For privacy: yes. Your PDF never leaves your device — everything runs in your browser. iLovePDF and Smallpdf upload your file to their servers. For compression power on native PDFs (vector text, form fields): server-side tools using Ghostscript can sometimes achieve smaller sizes. For scanned image-based PDFs, browser compression is equally effective.
Why is my compressed PDF larger than the original?
Some PDFs are already highly optimised internally (e.g., PDFs from Adobe Illustrator or Canva with efficient compression). Re-rendering and re-encoding them as JPEG can actually make them slightly larger. When this happens, the tool detects it and returns the original file unchanged.
Will my PDF remain searchable after compression?
No — this tool converts each page to a JPEG image, so text won't be selectable or searchable in the output. For portals that require text-based (searchable) PDFs, use Ghostscript or Adobe Acrobat's built-in reducer. For most portal uploads (job applications, exam forms), image-only PDFs are perfectly acceptable.
Can I compress a password-protected PDF?
No — password-protected PDFs can't be processed without the password. Remove the password protection in Adobe Reader first, then compress. If you don't have the password, you cannot compress the file.