xcprune

Find unused images, colors, and localization keys in an Xcode project.

Every app accumulates dead resources. An image survives the screen that used it, a localization key outlives the copy it translated, and nothing in Xcode tells you. They ship anyway, in every download, forever.

Xcode 15 changed the ground here twice: it generates a Swift symbol per asset, so references no longer appear as string literals, and it introduced String Catalogs (.xcstrings) for localization. Tools that match on string literals report live assets as dead against the first change. FengNiao handles images and asset symbols today and is worth using for that; it does not cover localization keys. xcprune reads both halves — asset catalogs and string tables including .xcstrings — and is built to be trusted rather than clever: anything it cannot resolve statically is reported as unresolved instead of guessed.

xcprune
Scanned 1 asset catalog(s), 1 string table(s), 142 source file(s), 9 interface file(s).

Unused images: 2
  onboarding_illustration_v1  — App/Assets.xcassets
  ic_legacy_share             — App/Assets.xcassets

Unused localization keys: 2
  legacy_onboarding_step_3 [Localizable]  — App/Localizable.xcstrings
  deprecated_error_banner [Localizable]   — App/Localizable.xcstrings

Runtime-decided names found — verify before deleting:
  image: App/MoodView.swift:11
    Image("mood_\(mood)")

4 unused of 318 declared.

Install

brew install helgafinn/tap/xcprune

Or build from source, which needs nothing but a Swift toolchain:

git clone https://github.com/helgafinn/xcprune
cd xcprune && swift build -c release
cp .build/release/xcprune /usr/local/bin/

Use

xcprune                      # scan the current directory
xcprune path/to/project
xcprune --only localizationKey
xcprune --format json
xcprune --fail-on-unused     # exit 1 when anything is unused, for CI

Option	Meaning
--format <pretty|json|github>	Output format. github emits workflow annotations
--only <kinds>	Comma-separated: image, color, symbol, dataAsset, localizationKey
--exclude <dir>	Directory to skip; repeatable
--ignore <name>	Treat a resource as used; repeatable
--fail-on-unused	Exit 1 when anything unused is found

What it understands

Assets from .xcassets — image sets, color sets, symbol sets, data sets — including namespaced folders. Localization keys from .strings, .stringsdict, and the modern .xcstrings string catalog.

It counts a resource as used when it finds any of:

• the name as a string literal, in Swift or Objective-C
• the symbol Xcode generates for it, so Image(.profileAvatar) reaches profile_avatar
• a storyboard or xib attribute, so image="header" counts
• an Info.plist entry, so app icons and launch images count
• implicit SwiftUI localization, so Text("welcome") reaches the key welcome

That third and fourth point are where older tools fail. Xcode 15 and later generate a Swift symbol per asset, so a modern codebase may never write an asset name as a literal at all. A tool that only greps for strings reports almost everything as unused, which is worse than useless.

Why it never deletes

xcprune reports. It does not delete, move, or rewrite anything.

The reason is that no static tool can be certain. UIImage(named: iconName) resolves at runtime, so any asset could be the one it loads. When xcprune sees a lookup like that it says so, names the file and line, and marks results for that kind low confidence — rather than staying silent and letting you delete something the app needs.

Getting this wrong is expensive and getting it right is unglamorous, so the bias is deliberate: a missed dead asset costs bytes, a false positive costs a broken build or a blank screen in production.

In CI

- uses: actions/checkout@v5
- run: brew install helgafinn/tap/xcprune
- run: xcprune --format github --fail-on-unused

Findings appear as annotations on the run. Drop --fail-on-unused to report without blocking.

Alongside periphery

periphery finds unused Swift code. xcprune finds unused resources. They do not overlap, and a project wanting both dead code and dead assets gone should run both.

Library

import XCPruneKit

let report = try Analyzer().analyze(ScanOptions(root: projectURL))
for resource in report.unused {
    print("\(resource.kind.label) \(resource.name)")
}
print(Reporter().render(report, as: .json))

FileSystem is a value, so scanning can be driven from fixtures without touching disk.

Requirements

macOS 12 or newer. No external dependencies.

License

MIT