Free Network & DevOps Tools
Fast utilities designed for systems engineers, network architects, and on-call practitioners. The calculators run entirely in your browser, so nothing you type leaves it.
What is my IP
Inspect the public IP address our edge proxy saw your connection from, including multi-hop X-Forwarded-For chains and proxy routing headers.
- Public IPv4 / IPv6 detection
- Reverse proxy header analysis
- Edge hop verification
CIDR Calculator
Instant browser-based IPv4 subnet mask calculator. Computes network address, broadcast, usable host ranges, and wildcard bitmasks.
- Real-time bit view calculation
- Subnet cheat sheet (/32 to /16)
- AWS VPC & Kubernetes sizing
Chmod Calculator
Interactive Linux file permission calculator. Convert octal to symbolic notation with SUID, SGID, and Sticky bit support.
- Interactive circular matrix
- Special permission bits (4000/2000/1000)
- Common DevOps & SSH presets
SLA & Uptime Calculator
Calculate allowed downtime for any SLA target and track error budget burn rate. Covers common nines from 99% to 99.999%.
- Downtime per day, week, month, quarter, year
- Error budget burn rate tracker
- Common nines reference table
Cron Explainer
Parse any 5-field cron expression into plain English and see the next 5 run times in your local timezone. Supports macros and presets.
- Plain-English schedule description
- Next 5 run times in local timezone
- Presets for common schedules
JWT Decoder
Decode and inspect JSON Web Tokens in your browser. Inspect header and payload claims with expiration checking. The token never leaves your device.
- Formatted JSON claims viewer
- exp / iat / nbf claim decoder
- 100% client-side decoding
Kubernetes Resource Units
Convert CPU millicores to cores and inspect binary (MiB/GiB) vs decimal (MB/GB) memory units. Understand why 512M is not 512Mi.
- Millicores to decimal core converter
- Binary vs decimal memory calculator
- Requests vs limits cheat sheet
Privacy-First
The CIDR, chmod, SLA, cron, JWT, and Kubernetes resource calculators run in your browser and send nothing anywhere. The IP tool asks our server which address it saw, and we keep only a salted hash of it for one minute, to rate-limit requests. No ads, no tracking cookies.