Quad9
quad9.netA public DNS resolver with malicious-domain blocking
A public DNS resolver with malicious-domain blocking
OpenPGP mailboxes bundled with encrypted file storage
Configurable browser with blocking and encrypted sync
Browse compatible encrypted filesystems inside Android
Check endpoint and job health, then turn failed checks into incidents and status-page updates.
Encrypted IPv6 overlay with public-key-derived addressing
Cloud DNS filtering with content and reporting controls
Check websites, endpoints, ports, DNS, and scheduled heartbeats, then send alerts when checks fail.
Probe HTTP, HTTPS, DNS, TCP, ICMP, and gRPC endpoints and expose results for Prometheus to scrape.
Define endpoint health checks and alert conditions in a lightweight self-hosted status dashboard.
Monitor website uptime, performance, certificates, and related site checks from one external service.
Keep a working folder and an encrypted folder in sync
Organize team messages, channels, and calls with optional end-to-end encrypted chats.
A Markdown notes app with wikilinks, graph views, offline work, and free encrypted sync.
A mobile crypto wallet with encrypted account backup and optional password recovery
Private business messaging with encrypted groups, files, voice calls, and disappearing messages.
A local-first personal knowledge workspace for private notes, linked objects, and databases.
Store notes and files in an encrypted notebook that syncs across devices.
A local-first desktop notebook that stores Markdown notes and canvases on the user’s computer.
Pre-1.0 encrypted team chat for organizations handling sensitive information.
A threaded team messenger with encrypted direct messages and optional agents inside workplace conversations.
Run network and application tests from global or private agents, then use path and routing views to locate where performance breaks.
Edit encrypted configuration without losing its familiar structure.