Two clean PDF editors with different strengths. One is a better editor. The other is smarter.
Sejda is an underrated PDF editor with genuinely good editing tools, flexible pricing (including a $5 weekly pass), and a desktop app that processes files locally. It's a smart choice for hands-on PDF editing.
ModernPDF processes PDF operations locally in the browser (no install), includes AI document analysis for contracts and legal documents, and costs $49/yr. It's less capable as a pure editor but smarter about what's inside your documents.
| Feature | ModernPDF | Sejda |
|---|---|---|
| File Privacy (Web) | PDF tools process locally; AI sends text via AES-256 encryption Winner | Files uploaded to Sejda servers |
| File Privacy (Desktop) | Local processing (browser) | Local processing (desktop app) — tie |
| AI Document Analysis | 10 document types, structured red-flag reports Winner | ✗ None |
| AI Translation | ✓ Claude-powered (50+ languages) Winner | ✗ None |
| AI Redaction | ✓ Auto-detect PII Winner | ✗ Manual whiteout only |
| PDF Editing | Basic (text, images, shapes, annotations) | More capable (edit existing text, links, forms) Winner |
| Fillable Forms | ✓ Fill existing forms | ✓ Create interactive forms Winner |
| PDF Tools | 28 tools | 30+ tools More tools |
| Free Tier | 3 tasks/day, 10MB | 3 tasks/hour, 50MB, 200 pages More generous |
| Desktop App | ✗ Web only | ✓ Windows, Mac, Linux Winner |
| Pricing Flexibility | Monthly ($9) or Annual ($49) | Weekly ($5), Monthly ($7.50), Annual ($63) More options |
| Annual Price | $49/yr Cheaper | $63/yr (Desktop+Web) |
| API | ✗ No API | ✓ Sejda API Winner |
Sejda is a better pure PDF editor than ModernPDF. It lets you click on existing text and change it, edit hyperlinks, create interactive form fields (checkboxes, dropdowns, text fields), whiteout content, and add bookmarks. Reviews consistently praise its editing capabilities — users describe it as the first PDF editor that "actually lets you edit" without the overhead of Adobe.
ModernPDF's editing is more basic: add text, images, shapes, highlights, and annotations. You can fill existing forms and add signatures. But you can't edit existing text in-place or create interactive forms. If your primary need is hands-on document editing, Sejda is the stronger tool.
Sejda has no AI features — no summarization, no translation, no chat, no document analysis. Like PDF24, it's a traditional toolkit that processes files without understanding their content.
ModernPDF's AI Document Analyzer reads your documents and provides structured analysis for specific document types. Upload a non-compete and get duration, geographic scope, exceptions, and enforceability red flags. Upload a lease and get rent terms, renewal provisions, termination clauses, and hidden costs. This isn't generic summarization — it's domain-specific intelligence that saves hours of manual review.
ModernPDF also includes AI translation (50+ languages via Claude) and AI redaction with automatic PII detection. Sejda offers basic whiteout, which visually hides content but requires you to find every sensitive item manually.
Sejda's online tools upload files to their servers — standard for web-based PDF tools. But Sejda also offers a desktop app (Windows, Mac, Linux) that processes files locally. If you use Sejda Desktop, your files never leave your computer. That's a real privacy advantage for desktop users.
ModernPDF processes all PDF operations locally in the browser — no desktop install needed. For AI features, only extracted text is sent to Anthropic's API via AES-256 bank-grade encryption — never the file itself. No text is stored after processing.
The distinction: Sejda requires a desktop install for local processing. ModernPDF achieves it in the browser. Both are meaningfully better than competitors that only offer server-side processing.
Sejda offers unusually flexible pricing: a $5 weekly pass (no subscription, expires after 7 days), $7.50/mo monthly, or $63/yr annual. The weekly pass is smart — if you have a one-time project, $5 gets you full access without committing to a subscription.
ModernPDF is $9/mo or $49/yr. No weekly option. On annual plans, ModernPDF is $14/yr cheaper ($49 vs $63). On monthly plans, Sejda is $1.50 cheaper ($7.50 vs $9).
No. Sejda is a traditional PDF editor without AI capabilities. ModernPDF includes AI document analysis, translation, and auto-redaction.
Sejda's web version uploads files to servers. The desktop app processes locally — files never leave your computer. If privacy matters, use Sejda Desktop or ModernPDF (which processes locally in the browser).
ModernPDF supports adding new text, images, shapes, and annotations, plus filling forms and signing. For editing existing text in-place, Sejda or Adobe Acrobat are more capable.
ModernPDF is cheaper annually ($49/yr vs $63/yr). Sejda is cheaper monthly ($7.50/mo vs $9/mo) and offers a $5 weekly pass for one-off projects.
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