PDF4U vs Gamma PDF

A side-by-side comparison built from both listings. Blank cells mean the company has not given that detail; we never guess.

PDF4U compared with Gamma PDF
Detail	PDF4U	Gamma PDF
What it does	Free PDF tools that run in your browser without uploading files to servers	Read papers. Keep what you learn.
Stage	Not given	Not given
Founded	Not given	Not given
Based in	Not given	Not given
Pricing model	Free	Freemium
Pricing	Not given	Free: desktop app and self-hosted server. Lite: $2/month or $20/year. Plus: $5/month or $50/year. Pro: $20/month or $200/year.
Key features	Not given	Highlight, draw, and annotate on PDFs with every mark becoming a note Outliner with live Markdown and LaTeX for mathematical notation AI chat to ask questions about papers with cited answers Full-library search across notes, highlights, and all PDFs Shared workspaces with live cursors and comments for collaboration Works offline on iPad, Android, and desktop with automatic sync Integrations with Zotero, Obsidian, Logseq, and Notion Browser extension for one-click saving papers with metadata
What makes it different	Files never leave your device - all processing happens in your browser No sign-up, no account required Unlimited usage with no daily caps or watermarks Works on phones, tablets and computers Available in 16 languages	Self-hosted option with one Docker image for full control over data Live math support with Markdown and LaTeX directly in outliner notes Works on any device: Windows, macOS, Linux, iPad, Android, and browsers No vendor lock-in with SQLite files and export at any time
Community votes	0	0
DR (Domain Rating by Ahrefs)	17 +1 (up) since last check	Not checked yet no change since last check
Trust Flow (Majestic)	4	0
Citation Flow (Majestic)	23	9
Referring domains (Majestic)	24	1

3 details filled in for both companies.

More alternatives to PDF4U More alternatives to Gamma PDF