Best Free PDF Compressor in 2026 — 6 Tools Tested

6 Best Free PDF Compressors — Tested with Real Files

We compressed the same 25 MB PDF (a 40-page report with photos) across 6 free tools. Here are the results.

Test Results

Tool	Output Size	Reduction	Quality	Speed	Free Limits
MyPDF	5.2 MB	79%	Excellent	Fast	Unlimited
PDF24	5.8 MB	77%	Excellent	Fast	Unlimited
iLovePDF	6.1 MB	76%	Good	Medium	2/day
Smallpdf	6.4 MB	74%	Good	Fast	2/day
Adobe Online	5.5 MB	78%	Excellent	Medium	Limited
Sejda	6.0 MB	76%	Good	Medium	3/hour

Rankings

1. MyPDF — Best Free PDF Compressor

MyPDF Compress PDF

• Best compression ratio in our tests (79% reduction)
• Three compression levels (Low, Medium, High)
• No daily limits — compress as many files as you want
• No watermarks
• Files auto-deleted after 15 minutes

Why it's #1: Best compression + truly unlimited + no watermarks.

2. PDF24 — Close Second

• Strong compression (77%)
• Also unlimited and free
• Offers desktop app for offline use
• Interface less modern than MyPDF

3. Adobe Acrobat Online — Good But Restricted

• Excellent compression (78%)
• Requires Adobe account
• Limited free compressions
• Constantly upsells to paid plan

4. iLovePDF — Good Quality, Limited Free

• Decent compression (76%)
• Only 2 free tasks per day
• Clean interface
• May add watermarks

5. Sejda — Quality With Limits

• Good compression (76%)
• 3 tasks per hour limit
• 200-page limit on free tier
• Clean interface

6. Smallpdf — Popular But Weakest

• Lowest compression in our test (74%)
• 2 tasks per day
• 5 MB file limit on free tier
• Pushes Pro heavily

Compression Level Guide

Most tools offer multiple compression levels:

Level	Use When	Typical Reduction
Low	You need near-original quality (print)	20-40%
Medium	Best balance for sharing and email	40-60%
High	You need the smallest file possible	60-80%

Tips for Maximum Compression

1. Start with Medium: Best quality-to-size ratio
2. Remove unnecessary pages first with Delete Pages
3. Convert to grayscale if color isn't needed: Grayscale PDF
4. Flatten the PDF first: Flatten PDF removes interactive overhead

Bottom Line

For unlimited, free PDF compression with the best results, MyPDF Compress PDF is the clear winner. No daily limits, no watermarks, and the highest compression ratio in our tests.