# About Subnet Mask vs VLSM | Subnet

The clearest difference is ads: VLSM | Subnet at none against About Subnet Mask's shown. About Subnet Mask's advantage is update cadence (every 9 days vs every 9 months). On price, in-app purchases, device support and iOS requirement there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

About Subnet Mask ships an update every 9 days, VLSM | Subnet every 9 months. The most recent releases landed on November 3, 2026 and October 17, 2026 respectively.

## The numbers

| Metric | About Subnet Mask | VLSM | Subnet |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/about-subnet-mask/id1662782439/reviews)** | — |
| Number of ratings | **1** | — |
| In-app purchases | No | No |
| Ads | Yes | **No** |
| Update frequency | **Every 9 days** | Every 9 months |
| Monetization | Ad-supported | — |
| Size | 9 MB | 23 MB |
| Requires iOS | **15.0** | 15.6 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Jaehwa Noh](https://appshunter.io/developer/1629220949) | [Edwin Mejia](https://appshunter.io/developer/1620400021) |

## What reviewers say

### About Subnet Mask

[App page](https://appshunter.io/ios/app/about-subnet-mask/id1662782439)

This utility tool calculates subnet masks based on IP and subnet inputs. It supports both IP and CIDR formats, determines class-based network numbers, and saves previous calculations for easy access. Users can also check the class of any IP address.

**Highlights:** Subnet mask calculation, IP and CIDR format support, Class-based network number calculation, IP class checking, Search history

**Features:** macOS Compatibility

**In-app purchases:** none


### VLSM | Subnet

[App page](https://appshunter.io/ios/app/vlsm-subnet/id6504495906)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is About Subnet Mask free?

About Subnet Mask is free to download, with no in-app purchases.

### Is VLSM | Subnet free?

VLSM | Subnet is free to download, with no in-app purchases.

### Do About Subnet Mask or VLSM | Subnet have ads?

About Subnet Mask shows ads; VLSM | Subnet does not.

### Which is updated more often, About Subnet Mask or VLSM | Subnet?

About Subnet Mask ships an update every 9 days, and VLSM | Subnet every 9 months. Most recently, About Subnet Mask was updated on November 3, 2026 and VLSM | Subnet on October 17, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*