# CIDR vs About Subnet Mask

The clearest difference is in-app purchases: About Subnet Mask at none against CIDR's 1. About Subnet Mask also leads on update cadence (every 9 days vs every 3 weeks). CIDR's advantage is ads (none vs shown). On price, rating, ratings volume and device support there is nothing between them.

Both are free to download. CIDR sells 1 one-off in-app purchase. About Subnet Mask asks for nothing beyond the download.

On the App Store both sit at effectively the same score — 5.0 for CIDR against 5.0 for About Subnet Mask. Both are backed by a comparable volume of ratings — 1 and 1 respectively.

CIDR ships an update every 3 weeks, About Subnet Mask every 9 days. The most recent releases landed on June 30, 2026 and September 10, 2026 respectively.

## The numbers

| Metric | CIDR | About Subnet Mask |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [5.0 (1 ratings)](https://appshunter.io/ios/app/cidr/id1564239813/reviews) | [5.0 (1 ratings)](https://appshunter.io/ios/app/about-subnet-mask/id1662782439/reviews) |
| Number of ratings | 1 | 1 |
| In-app purchases | Yes | **No** |
| Ads | **No** | Yes |
| Update frequency | Every 3 weeks | **Every 9 days** |
| Monetization | **Free** | Ad-supported |
| Size | 23 MB | 9 MB |
| Requires iOS | 15.6 | **15.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [ao-system, Inc.](https://appshunter.io/developer/1338624340) | [Jaehwa Noh](https://appshunter.io/developer/1629220949) |

## What reviewers say

### CIDR

[App page](https://appshunter.io/ios/app/cidr/id1564239813)

This utility calculates IP address ranges from an IP address and subnet mask. It supports IPv4 calculations, including prefix display, address range counts, and bit notation. Useful for quick CIDR notation checks and subnet mask conversions.

**Highlights:** IP address range calculation, Subnet mask to CIDR conversion, IPv4 prefix display, Number of address ranges, Bit notation display, Quick reference table

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Remove Ads | $1.99 | one-time |


### 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


## Frequently asked questions

### Is CIDR free?

CIDR is free to download, with in-app purchases available.

### Is About Subnet Mask free?

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

### Which has better reviews, CIDR or About Subnet Mask?

CIDR and About Subnet Mask are both rated 5.0 out of 5 on the App Store, from 1 and 1 ratings respectively.

### Do CIDR or About Subnet Mask have ads?

About Subnet Mask shows ads; CIDR does not.

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

CIDR ships an update every 3 weeks, and About Subnet Mask every 9 days. Most recently, CIDR was updated on June 30, 2026 and About Subnet Mask on September 10, 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.*