# PrefixForge: IPv4 Subnet Tools — CIDR plans, masks & addresses

> CIDR plans, masks & addresses (iPhone/iPad app by Bryl Kezter Lim.)

- Source: https://appshunter.io/ios/app/prefixforge-ipv4-subnet-tools/id6818262212 (this page in markdown: same URL + `.md`)
- Developer: [Bryl Kezter Lim](https://appshunter.io/developer/1609198408)
- Category: Developer Tools, Reference
- Price: $3.99
- Age rating: 4+
- Requires: iOS 18.0 · 1 MB
- Languages: American English
- Released: 2026-10-02
- Data updated: 2026-10-06
- User reviews in markdown: https://appshunter.io/ios/app/prefixforge-ipv4-subnet-tools/id6818262212/reviews.md

## What is PrefixForge?

Plan IPv4 networks with clear CIDR arithmetic and saved local notes. PrefixForge is an offline tool for developers, network learners and anyone organizing an address plan.

• Enter an IPv4 host or network with a /0–/32 prefix. See the normalized network, subnet mask, directed broadcast, wildcard mask, address range and host capacity.
• Understand /31 point-to-point endpoints and /32 host routes with explicit explanations instead of misleading network/broadcast reservations.
• Split a parent network into equal-size child subnets, with up to 256 rows. Inspect each child’s boundaries or share the subnet table as text.
• View binary addresses and masks, plus the count of network and host bits.
• Check whether an address lies inside a CIDR block.
• Classify the input address against common private, shared, link-local, loopback, documentation and other special ranges.
• Save named network plans with purpose and reservation notes. Edit, delete and export them as text.
• Consult an offline table of all 33 prefix lengths and original explanations of CIDR planning.

Works on iPhone and iPad with no account, ads, analytics, tracking or in-app purchases. Calculations and saved plans work entirely offline.

PrefixForge calculates address boundaries; it does not discover devices, scan networks, test connectivity, configure equipment, or check address availability. Host counts describe conventional arithmetic capacity and may not equal assignable capacity in special-purpose ranges. The common-range table is not exhaustive and is not a live allocation or routability database. IPv6, VLSM optimization and DNS lookup are not included.


## Version history (last 1 release)

### 1.0.0 — 2026-10-02

No release notes.

## More apps by Bryl Kezter Lim

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- [Adie: Baby & Toddler Journal](https://appshunter.io/ios/app/adie-baby-and-toddler-journal/id6817685062)

All apps by Bryl Kezter Lim: https://appshunter.io/developer/1609198408

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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 2026-10-06.*