swiftui-performance-audit Skill for Claude: What It Does and How to Install It

Makes Claude audit SwiftUI performance from your code first, then guide you through Instruments profiling when code review is not enough.

Installs: 10.1K; on skills.sh
Stars: 4K; on GitHub
Files: 8; besides SKILL.md
Updated: Mar 2026; last repo commit

This skill makes Claude diagnose slow SwiftUI by reading your code first. It looks for invalidation storms, unstable identity in lists, heavy work in body, layout thrash, image decoding on the main thread and over-broad animations.

If the code does not explain it, Claude asks you to run Instruments and share the evidence. It does not run the profiler itself. The final report follows a template with summary, findings, metrics and next step.

Good for

iOS developers with janky scrolling or high CPU
Teams chasing excessive view updates
Anyone preparing a performance report with before and after numbers

Install swiftui-performance-audit

Claude Code

Copy this prompt.

Install the swiftui-performance-audit skill in Claude Code. Run this command:

npx skills add https://github.com/dimillian/skills --skill swiftui-performance-audit

Then check that it loaded and tell me how to use it.

2
Paste it into Claude Code. It shows the change and asks before running it.

Requires Node.js.

From its listing on skills.sh. Source.

What's in the skill

When it loads

Audit and improve SwiftUI runtime performance from code review and architecture. Use for requests to diagnose slow rendering, janky scrolling, high CPU/memory usage, excessive view updates, or layout thrash in SwiftUI apps, and to provide guidance for user-run Instruments profiling when code review alone is insufficient.

Sections in SKILL.md

Quick start
Workflow
1. Intake
2. Code-First Review
3. Guide the User to Profile
4. Analyze and Diagnose
5. Remediate
6. Verify
Outputs
References

Key facts

Author: Dimillian (Thomas Ricouard)
License: MIT (crawl data; SKILL.md and README state none)
Installs on skills.sh: 10,131 (Nov 2, 2026)
GitHub stars: 4,021 for the whole dimillian/skills repo (Nov 2, 2026)
Last repo commit: Mar 29, 2026
What it includes: 9 files including SKILL.md: 7 reference files and agents/openai.yaml. No scripts
Needs: Your SwiftUI code. For runtime evidence it asks you to run Instruments yourself and share a trace or screenshots
Part of: Dimillian/skills, a repo of 16 skills for Apple platforms and other tasks

What it includes

Target view, symptoms, reproduction steps, data flow, Debug or Release
Asks you to classify the problem as CPU, scrolling, memory, hangs or excess view updates.
Try: “Why does this list stutter when I scroll? Review it for SwiftUI performance issues.”
Read · 1. Intake
Six focus areas with a catalog of code smells
Uses references/code-smells.md, which lists 7 high-priority smells, observation fan-out for @Observable and ObservableObject, and a triage order.
Read · 2. Code-first review
Asks for a trace or screenshots from Instruments
Asks for the SwiftUI timeline and Time Profiler call tree, device and OS, and the exact interaction. You run the capture.
Read · 3. Guide the user to profile
Map evidence to a category and rank by impact
Separates code-level suspicion from trace-backed evidence and says when profiling is still not enough.
Read · 4. Analyze and diagnose
Narrow state, stable IDs, move work out of body, downsample images
Applies targeted fixes to your code. It warns that @State is not a general cache and equatable() only helps in some cases.
Write · 5. Remediate
Re-run the same capture and compare with the baseline
Summarizes the change in CPU, frame drops and memory peak if you give the numbers.
Read · 6. Verify
Summary, findings, metrics table and next step
Findings are ordered by impact and say whether a conclusion is still a hypothesis.
Read · Audit report template

From the official docs

Permissions

Low risk

Claude can edit your SwiftUI files when it applies fixes. Review the diff, and keep traces you share free of private data.

What it can do

Read your data
Create and change things
Delete things
Read-only mode

Watch out for

It edits your SwiftUI code
Step 5 of SKILL.md says to apply targeted fixes, such as narrowing state, stabilizing identities and moving work out of body. Review the diff before you commit. github.com

Security advisories

No published security advisories as of Nov 2, 2026.

Technical details

Turning on read-only	No read-only mode. Use version control.
Sign-in and keys	SKILL.md mentions no account or key.
Scopes	In the Remediate step, Claude applies fixes to your SwiftUI code Profiling with Instruments is run by you; Claude reads the trace or screenshots you share

Questions

What does the swiftui-performance-audit skill do?

It makes Claude review SwiftUI code for performance problems. Claude looks for causes of slow rendering, janky scrolling, high CPU or memory use, and excess view updates.

How do I install it?

Use the install box at the top of this page. The repo README says to place the skill folders under $CODEX_HOME/skills. The skill is a SKILL.md with reference files and no scripts.

Does it run Instruments for me?

No. SKILL.md says it provides guidance for user-run Instruments profiling. Claude tells you what to capture and reads the trace or screenshots you share.

Can it work without my code?

Yes, in a limited way. If code is not available, SKILL.md has Claude ask for the smallest useful slice: the target view, data flow, reproduction steps and deployment target.

Is it safe?

It bundles no scripts. In the remediate step Claude can edit your SwiftUI code, so review the diff. Traces or screenshots you share go to your assistant like any other file.

Information

updated Nov 2, 2026

Repository: dimillian/skills
Folder: swiftui-performance-audit

dimillian/skills skills.sh

Sources

Docs, issue trackers and discussions this page is built from.

Show all 4

swiftui-performance-audit SKILL.md · github.com
Dimillian/Skills README · github.com
code-smells.md · github.com
profiling-intake.md · github.com