# OctetLab: Subnet Calculator — VLSM planner, IPv6, offline

> VLSM planner, IPv6, offline (iPhone/iPad app by 永 张.)

- Source: https://appshunter.io/ios/app/octetlab-subnet-calculator/id6791678289 (this page in markdown: same URL + `.md`)
- Developer: [永 张](https://appshunter.io/developer/1806535769)
- Category: Utilities
- Price: Free with in-app purchases
- Age rating: 4+
- Requires: iOS 26.0 · 1 MB
- Languages: American English, Chinese (Simplified, China)
- Released: 2026-07-24
- Data updated: 2026-07-28
- User reviews in markdown: https://appshunter.io/ios/app/octetlab-subnet-calculator/id6791678289/reviews.md

## What is OctetLab?

OctetLab is a subnet calculator built for network engineers, sysadmins, and students who need answers in seconds, not spreadsheets. Enter an IPv4 or IPv6 address and instantly see the network address, broadcast address, usable host range, and subnet mask — broken down bit by bit in a visualizer you can tap to reshape the mask boundary by hand.

Every calculation runs fully on-device: no accounts, no network calls, no ads.

INCLUDED
• Instant IPv4 subnet calculator with a tap-to-toggle binary bit visualizer — see and shape the mask boundary directly
• Full IPv6 subnet support, including compressed and expanded address forms
• Copy any result field or share a full subnet summary in one tap
• Save your recent calculations to a running history

PRO (ONE-TIME UNLOCK)
• VLSM subnet splitter — divide a network into right-sized subnets by host count
• Unlimited saved calculation history
• Export subnet plans to CSV

OctetLab does one job well: turning subnetting math into a clean, tappable interface — no lookup tables, no guesswork.

Terms of Use (EULA): https://obelisk.club/subnetmaskcalculator/terms

## Pricing and in-app purchases

Base price: Free.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| SubnetMaskCalculator Pro | $4.99 | one-time |



## Version history (last 1 release)

### 1.0 — 2026-07-24

No release notes.

## More apps by 永 张

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- [IDKit: Passport & ID Photos](https://appshunter.io/ios/app/idkit-passport-and-id-photos/id6769530845)
- [ShotKit: Screenshot Studio](https://appshunter.io/ios/app/shotkit-screenshot-studio/id6777430919)
- [NearBeam: Local File Transfer](https://appshunter.io/ios/app/nearbeam-local-file-transfer/id6777431459)

All apps by 永 张: https://appshunter.io/developer/1806535769

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-07-28.*