The four contenders
iLovePDF — the most popular free PDF tool. 25+ operations, 25 MB file limit on free tier, $7/month Pro. Server-based (uploads your files).
Smallpdf — the prettiest UI. 20+ operations, 5 MB file limit on free tier, 2 tasks/day free, $9/month Pro. Server-based.
Adobe Acrobat Online — the official Adobe web version. Excellent quality, 5 tasks/month free with Adobe account, $20/month Pro. Server-based.
PrivacyScanPDF (mine) — 19+ operations, no file size limit, no daily caps, no signup. Browser-based (zero uploads). Free with optional $79 lifetime Pro. Includes AI-powered PII scanner.
Privacy: the biggest differentiator
This is where the tools diverge most sharply. iLovePDF, Smallpdf, and Adobe Online all upload your files to their servers for processing. Their Terms of Service promise deletion (usually within hours), but you can't audit the deletion, and multiple major PDF services have been caught retaining files for 'service improvement' (training ML models).
PrivacyScanPDF has no upload endpoint. Every operation runs as JavaScript in your browser tab. You can verify this in your browser's DevTools (F12 → Network tab) — zero file upload requests during any operation. This isn't a marketing claim; it's verifiable in 30 seconds.
Practical implication: for sensitive documents (contracts, medical records, tax filings, anything with PII), only PrivacyScanPDF is safe to use. For non-sensitive PDFs (public reports, blog posts, marketing material), all four work — but server-based tools offer no advantage over browser-based.
Feature comparison
iLovePDF wins on tool count: 25+ operations including some niche ones (PDF to FB2, PDF to RTF) that no one else offers. PrivacyScanPDF has 19+, Smallpdf has 20+, Adobe has ~15 on the web version (more in the desktop app).
PrivacyScanPDF wins on unique features: the AI-powered PDF Privacy Scanner (detects 50+ PII patterns, metadata leaks, embedded scripts, produces a 0-100 risk score) is not available on any of the other three at any price. Adobe has a basic redaction tool in Pro; iLovePDF and Smallpdf don't have PII scanning at all.
Adobe wins on conversion quality, especially PDF-to-Word. Their neural-network-based conversion handles complex layouts (multi-column, tables, custom fonts) better than any free tool. If you convert PDFs daily as part of your job, Acrobat Pro ($20/month) is worth it for this alone.
Smallpdf wins on UI polish. The cleanest, most intuitive interface of the four. If you're willing to pay $9/month and don't care about uploads, Smallpdf is the most pleasant to use.
Pricing comparison
PrivacyScanPDF: $0 free (unlimited) / $79 lifetime Pro (one-time payment, no recurring fee). Best value over 12+ months.
iLovePDF: $0 free (25 MB limit) / $7/month Pro ($84/year). Best for casual users who don't mind uploads and need the 25 MB cap lifted.
Smallpdf: $0 free (5 MB limit, 2 tasks/day) / $9/month Pro ($108/year). Most expensive, but the UI is genuinely better.
Adobe Acrobat Online: $0 free (5 tasks/month, Adobe account required) / $20/month Pro ($240/year, or included with Creative Cloud). Most expensive, but best conversion quality and tightest integration with Adobe's ecosystem.
Over 2 years: PrivacyScanPDF Pro costs $79 total. iLovePDF Pro costs $168. Smallpdf Pro costs $216. Adobe Pro costs $480. PrivacyScanPDF is 2-6× cheaper over time.
When to use which
Use PrivacyScanPDF if: you handle sensitive documents (contracts, medical, financial), you want zero uploads, you scan PDFs for PII, you want unlimited free use, or you're cost-conscious over the long term.
Use iLovePDF if: you need a specific niche tool (PDF to FB2/RTF/etc.), you're fine with uploads, you need the 25 MB cap lifted occasionally, and you don't mind $7/month. Most popular for a reason — it works.
Use Smallpdf if: you value UI polish above all, you only need 2-3 PDF tasks per day, and you're willing to pay $9/month for the Pro tier. The prettiest of the four.
Use Adobe Acrobat Online if: you convert complex PDFs to Word/Excel daily, you need the best conversion quality, you're already in Adobe's ecosystem (Creative Cloud subscriber), or you need Adobe's specific enterprise features (e-signature tracking, document analytics).
You don't have to pick one. Most users end up with two: PrivacyScanPDF for sensitive documents (zero uploads) + iLovePDF or Adobe for non-sensitive tasks where conversion quality matters.