About the tools

Part of zrina.app · Last updated: November 2026

These independent browser-based utilities are built and maintained by Zrina as a separate part of zrina.app. They are intended to make common network and developer tasks easier without requiring an account.

Available tools

• HostVitals — compare browser, edge and DNS checks with official status summaries for supported services.
• Download Time Calculator — estimate transfer time or the speed needed to meet a deadline.
• Subnet & CIDR Calculator — calculate IPv4 network details.
• JSON Formatter — format, minify and validate JSON in your browser.
• Unix Timestamp Converter — convert between timestamps and dates.
• Cron Explainer — explain schedules and show upcoming run times.
• Network & IP Inspector — view public IP and network information.
• UUID Inspector — inspect UUID, ULID, ObjectId and Snowflake identifiers and byte order.
• Network Planner — review IPv4/IPv6 overlaps and gaps and plan subnet allocations.
• QR Code Generator — create QR codes for text, links, Wi-Fi, contacts and messages.
• Password Generator — generate random passwords and passphrases using your browser's cryptographic random source.
• Base64 Encoder / Decoder — encode or decode text and files in your browser.
• Regex Tester — test JavaScript regular expressions with match highlighting, captures and replacement previews.
• Unit Converter — convert data sizes, length, mass, temperature and speed.

Questions or feedback?

Browse practical tool guides and technical references for detailed examples and troubleshooting.

For questions about these tools, contact [email protected]. HostVitals-specific methodology is described on its About page.