# class-dump

> Command-line utility that reads the Objective-C runtime metadata in Mach-O executables, frameworks and bundles and prints it as ordinary Objective-C declarations for the classes, categories and protocols it finds, the same information otool -ov shows in a more compact form. It can write one header file per class, recurse into the frameworks a binary uses, choose one architecture from a universal binary, filter or sort the output, and annotate it with instance-variable offsets and implementation addresses.

- Type: Tool
- Targets: App · Binary
- Category: Native analysis tools
- Relationship: Foundation tool
- Sources reviewed: 2026-10-19
- Added to the catalog: 2026-10-30
- Original resource: <https://github.com/nygard/class-dump>
- Primary source: <https://github.com/nygard/class-dump/blob/2c82b4ff12b2ea5d1ac23e49281d496997370841/README.md>
- Catalog page: <https://awesomerea.org/resources/class-dump/>
- Record JSON: <https://awesomerea.org/resources/class-dump/record.json>
- Chinese version: [简体中文](https://awesomerea.org/zh/resources/class-dump/index.md)

## Requirements & limits

- Dormant: the newest tag, 3.5, is dated 2013-11-16, GitHub release entries stop at 3.4, and the README points to the author's website for the latest version. The reviewed master commit, from 2019-03-15, is 75 commits past 3.5 and carries unreleased changes such as building with the macOS 10.14 SDK.
- Builds use Xcode on macOS with the bundled class-dump.xcodeproj, whose targets set macOS 10.8 and 10.9 deployment targets. The README's usage text lists ppc, ppc64, i386 and x86_64, and the 3.5 changelog adds arm64; support for later Apple architectures or metadata formats is not documented.
- Input is a Mach-O file, framework or bundle the user already has, and only Objective-C metadata is decoded; files with an encryption load command are flagged in the output header. The unreleased changelog says Swift types have a blank encoding and are now written as MISSING_TYPE, so Swift types are not recovered. Output is declarations without method bodies.
- Tests/doTests.py is a Python 2 script that diffs an older and a newer build's output over the installed system frameworks; the repository has no CI. The README notice applies GPL-2.0-or-later, copyright 1997-2019 Steve Nygard, and there is no separate license file; ThirdParty/blowfish.c is LGPL-2.1-or-later. Headers generated from closed-source binaries remain subject to their owners' rights.

## Primary sources

1. <https://github.com/nygard/class-dump/blob/2c82b4ff12b2ea5d1ac23e49281d496997370841/README.md>
2. <https://github.com/nygard/class-dump/blob/2c82b4ff12b2ea5d1ac23e49281d496997370841/CHANGELOG.md#L1-L15>
3. <https://github.com/nygard/class-dump/blob/2c82b4ff12b2ea5d1ac23e49281d496997370841/class-dump.xcodeproj/project.pbxproj>
4. <https://github.com/nygard/class-dump/blob/2c82b4ff12b2ea5d1ac23e49281d496997370841/Source/CDClassDumpVisitor.m#L104-L112>
5. <https://github.com/nygard/class-dump/blob/2c82b4ff12b2ea5d1ac23e49281d496997370841/Tests/doTests.py>
6. <https://github.com/nygard/class-dump/blob/2c82b4ff12b2ea5d1ac23e49281d496997370841/ThirdParty/blowfish.c>
7. <https://github.com/nygard/class-dump/releases/tag/3.4>

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## About this entry

The description was reviewed against primary sources.
Original editorial content: MIT. Linked projects, papers and assets retain their own rights and licenses.