IPCalc Pro

Professional IPv4 Calculator and Subnetting Tool for Visual Studio Code

IPCalc Pro is a fast, lightweight IPv4 calculator and subnetting engine built natively into Visual Studio Code. No browser, no external tools — just open the panel and get instant results as you type.

Features

Real-time IPv4 Analysis

• Network address, broadcast, host range, netmask, wildcard mask and usable host count — updated instantly on every keystroke
• Binary representation for Address, Netmask, Wildcard, Network, HostMin, HostMax and Broadcast
• IP class detection — Class A / B / C / D (Multicast) / E (Reserved) / Loopback / Reserved
• Public vs Private classification with correct RFC ranges (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16)

Input Validation

• Strict octet validation — each octet must be 0–255, rejects leading zeros and non-numeric input
• Visual feedback: input border turns green for valid input, red for invalid
• Clear inline error messages for malformed IPs and out-of-range prefixes

VLSM Subnet Builder

• Split any network into N optimally-sized segments
• Uses binary subdivision — each split halves the largest available block
• Adjustable segment count via stepper control (1–128)

FLSM Subnet Builder

• Divide a network into equal fixed-size segments by specifying a target CIDR mask
• Shows all subnets with their host ranges (up to 128 subnets)

Subnet Builder — per-row details

• Netmask (dotted decimal) displayed on each subnet row, color-coded in red to match the Analysis panel
• Broadcast address displayed on each subnet row, color-coded in blue to match the Analysis panel
• Host range (HostMin – HostMax) displayed between netmask and broadcast

Copy to Clipboard

• One-click copy button on every subnet row
• Visual confirmation (checkmark feedback)

UI

• Terminal-inspired dark theme (JetBrains Mono font)
• Two-panel layout: Analysis on the left, Builder on the right
• Activity Bar icon — click the IPCalc Pro icon in the left sidebar to open instantly, no Command Palette needed
• Fully self-contained — no CDN dependencies, no React, no Babel, no internet connection required
• Retains panel state when switching editor tabs

How to Use

1. Open the Command Palette (Ctrl+Shift+P / Cmd+Shift+P on macOS)
2. Type IPCalc Pro: Open Calculator and press Enter — or simply click the IPCalc Pro icon in the Activity Bar (left sidebar)
3. The panel opens — type any IP/CIDR in the input field (e.g. 192.168.1.0/24)
4. Analysis updates in real time — switch between VLSM and FLSM in the Builder panel

Examples

Requirements

• Visual Studio Code 1.80.0 or higher
• No additional dependencies
• Works fully offline — no internet connection needed

Extension Commands

Known Limitations

• IPv4 only — IPv6 is not currently supported

Release Notes

See CHANGELOG.md for the full release history.

License

MIT — Developed by powerfrankk