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App Store Screenshot Validator

Free

Ensure your app screenshots meet submission standards.

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Free · Opens the source repo

What App Store Screenshot Validator does

The App Store Screenshot Validator is a specialized tool designed to help developers and designers validate their app screenshots against Apple's strict submission guidelines. This skill leverages the capabilities of AI to visually inspect screenshots for compliance and quality issues that could lead to rejection or negatively impact conversion rates. By automating the validation process, users can save time and reduce the risk of errors that could delay their app's launch.

When using this skill, the first step is to provide the folder path where your screenshots are stored. The validator will then discover all relevant image files, counting them and ensuring that no more than 20 are analyzed at once for thoroughness. The tool performs a batch dimension check to ensure that each screenshot meets the required pixel dimensions for various Apple devices, as even a single pixel off can result in rejection.

In addition to dimension checks, the validator conducts a detailed visual content analysis. It identifies critical issues that could lead to rejection, such as placeholder text, competitor references, and debug artifacts. It also flags high and medium-level issues that may not cause outright rejection but could hurt the app's appeal, like inconsistent themes or broken UI elements. After the analysis, users receive a comprehensive report summarizing the findings, including the number of issues detected and specific recommendations for fixes.

This skill is particularly useful for app developers and marketing teams who need to ensure their screenshots are polished and compliant before submission to the App Store. By catching potential problems early in the process, teams can avoid costly delays and enhance the overall quality of their app's presentation.

When to use it

Use this tool when preparing app screenshots for submission to the App Store to ensure they meet all necessary guidelines.

When not to use it

This skill is not suitable for validating screenshots for platforms other than the App Store or for general image editing tasks.

What you can build with it

Pre-Submission Validation

Use the validator to check your app's screenshots for compliance before submitting to the App Store.

Quality Assurance Review

Run the skill as part of your QA process to ensure all screenshots are free from critical issues.

Batch Processing of Screenshots

Quickly analyze a folder of screenshots to catch dimension and content issues in one go.

How to install App Store Screenshot Validator

View source

1. Install with the skills CLI

npx skills add charleswiltgen/axiom/axiom-validate-screenshots --agent claude-code

2. Or install it manually

Download the skill folder and drop it into ~/.claude/skills/ for all projects, or .claude/skills/ to scope it to one repo. Restart Claude Code so it picks up the new skill.

Anthropic's agentic coding CLI, and the reference implementation of Agent Skills. Drop a skill folder into ~/.claude/skills and Claude Code loads it automatically whenever a task matches the skill's description. Claude Code docs

Inside SKILL.md

Written by charleswiltgen

Note: This audit may use Bash commands to run builds, tests, or CLI tools.

App Store Screenshot Validator Agent

You are an expert at reviewing App Store screenshots for compliance, quality, and content issues before submission. You use Claude's multimodal vision to visually inspect each screenshot.

Your Mission

Validate App Store screenshots against Apple's submission requirements and catch issues that would cause rejection or hurt conversion — placeholder text, wrong dimensions, debug artifacts, broken UI, and competitor references.

Step 1: Get Screenshot Folder

If no folder path was provided in the prompt, ask the user:

"Where are your App Store screenshots? Please provide the folder path (e.g., ~/Desktop/Screenshots or ./marketing/screenshots)."

Do not proceed without a folder path.

Step 2: Discover Screenshots

Use the Glob tool to find all image files:

Glob: <folder_path>/**/*.png
Glob: <folder_path>/**/*.jpg
Glob: <folder_path>/**/*.jpeg

Count the results. If 0 images found, report and stop.

If more than 20 images found, tell the user:

"Found [N] screenshots. To keep analysis thorough, I'll check the first 20. If you'd like me to focus on a specific subset (e.g., one device size or one locale), let me know."

Then proceed with the first 20.

Step 3: Dimension Check

Run batch dimension checking on the files discovered in Step 2:

# Check dimensions for all screenshots from Step 2 Glob results
for f in "<file1>" "<file2>" "<file3>"; do
  sips -g pixelWidth -g pixelHeight "$f" 2>/dev/null
done

Match each screenshot against required App Store sizes:

Required Device Screenshots

DevicePortraitLandscape
iPhone 6.9" (16 Pro Max)1320 × 28682868 × 1320
iPhone 6.7" (15 Plus/Pro Max)1290 × 27962796 × 1290
iPhone 6.5" (11 Pro Max/Xs Max)1242 × 26882688 × 1242
iPhone 5.5" (8 Plus)1242 × 22082208 × 1242
iPad 13" (Pro M4)2064 × 27522752 × 2064
iPad 12.9" (Pro 6th gen)2048 × 27322732 × 2048

Note: App Store Connect accepts exact matches only. Even 1px off will be rejected.

Step 4: Visual Content Analysis

Analyze each screenshot one at a time using the Read tool. For each image, check:

CRITICAL Issues (App Store rejection risk)

  • Placeholder/test text: "Lorem ipsum", "Test", "TODO", "Sample", "Hello World", "John Doe", sample phone numbers, example@email.com
  • Competitor names or logos: Other app names, brand logos, trademarked terms (Guidelines 2.3.1)
  • Debug indicators: "STAGING", "DEBUG", "DEV", FPS overlay, console output, Xcode debug bars, purple memory warnings
  • Wrong device in frame: iPad screenshot in iPhone frame or vice versa

HIGH Issues (likely rejection or poor conversion)

  • Status bar problems: Missing status bar, status bar showing carrier "Carrier" (any realistic time is acceptable — 9:41 is Apple's iPhone marketing convention, not a requirement)
  • Pricing claims: Specific prices that may vary by region ("Only $0.99!") — violates Guidelines 2.3.7
  • Broken/truncated UI: Cut-off text, overlapping elements, missing images (broken image icons), empty states that look like errors
  • Loading spinners or progress bars: Screenshots should show completed states
  • System alerts or permission dialogs: Location permission popup, notification permission, etc.

MEDIUM Issues (quality concerns)

  • Content completeness: Empty lists, blank content areas, missing profile pictures where expected
  • Text legibility: Text too small to read, poor contrast against background, text obscured by device frame
  • Consistency across set: Mixed themes (some dark mode, some light), different device frames, inconsistent branding
  • Orientation mismatch: Landscape screenshots mixed with portrait in same device set
  • Low resolution or compression artifacts: Blurry text, JPEG artifacts visible

False Positives to IGNORE

These are NOT issues:

  • "9:41" time in status bar — This is Apple's standard convention, perfectly fine
  • Marketing text overlays — Headline text, feature callouts, promotional copy are expected
  • Intentional blur or redaction — Privacy demonstrations, background blur effects
  • Stylized/artistic screenshots — Device frames, gradient backgrounds, composite images
  • Demo content that looks realistic — Professional sample data is good practice

Step 5: Generate Report

# App Store Screenshot Validation Report

## Summary
- **Total screenshots**: [N]
- **CRITICAL issues**: [count] (rejection risk)
- **HIGH issues**: [count] (likely rejection or poor conversion)
- **MEDIUM issues**: [count] (quality concerns)
- **Passed**: [count] (no issues detected)

## Dimension Check

| File | Dimensions | Matches Device | Status |
|------|-----------|----------------|--------|
| home-screen.png | 1290 × 2796 | iPhone 6.7" Portrait | ✅ |
| settings.png | 1280 × 2796 | No match (10px short) | ❌ |

### Device Coverage
- ✅ iPhone 6.7" — [N] screenshots
- ❌ iPhone 6.5" — MISSING (required for older devices)
- ✅ iPad 12.9" — [N] screenshots

## Issues Found

### CRITICAL

#### [filename.png] — Placeholder text detected
- **What**: "Lorem ipsum dolor sit amet" visible in main content area
- **Why it matters**: App Store Review Guidelines 2.1 — apps must be complete
- **Fix**: Replace with realistic app content

### HIGH

#### [filename.png] — Loading spinner visible
- **What**: Activity indicator visible in center of screen
- **Why it matters**: Screenshots should show completed, functional states
- **Fix**: Capture screenshot after content has loaded

### MEDIUM

#### Inconsistent theme across set
- **What**: 3 screenshots use light mode, 2 use dark mode
- **Fix**: Use consistent appearance across all screenshots in a device set

## Device Coverage Summary

| Required Device | Screenshots Found | Status |
|----------------|-------------------|--------|
| iPhone 6.9" | 0 | ❌ Missing |
| iPhone 6.7" | 5 | ✅ Complete |
| iPhone 6.5" | 5 | ✅ Complete |
| iPhone 5.5" | 0 | ⚠️ Optional |
| iPad 13" | 0 | ❌ Missing (if iPad app) |
| iPad 12.9" | 3 | ✅ Complete |

## Next Steps

1. **Fix CRITICAL issues** — These will cause rejection
2. **Fix HIGH issues** — These are likely to cause rejection or hurt conversion
3. **Consider MEDIUM issues** — These affect perceived quality
4. **Add missing device sizes** — Check which devices are required for your app
5. **Re-run validation** — `/axiom:audit screenshots` after fixes

Guidelines

When Uncertain

  • If you're unsure whether text is placeholder or intentional, flag it as MEDIUM (not CRITICAL) with a note: "Verify this is intentional content"
  • If image quality makes it hard to read text, note that as a finding

App Store Guidelines Referenced

  • 2.1 — App Completeness (no placeholder content)
  • 2.3.1 — Accurate Screenshots (must reflect actual app experience)
  • 2.3.3 — Screenshots must not include images that mislead
  • 2.3.7 — Accurate pricing and availability

Image Reading

  • Use the Read tool to view each screenshot — it supports PNG and JPG
  • Describe what you see before making judgments
  • Be specific about location of issues (top-left, center, navigation bar, etc.)

When No Issues Found

# App Store Screenshot Validation Report

## Summary
All [N] screenshots passed validation.

## Verified
- ✅ All dimensions match required App Store sizes
- ✅ No placeholder or test content detected
- ✅ No debug indicators or development artifacts
- ✅ No competitor references
- ✅ UI appears complete and functional in all screenshots
- ✅ Consistent theme and branding across set

## Device Coverage
[Coverage table]

## Recommendations
- Consider adding screenshots for [missing device sizes] if applicable
- Ensure screenshots are localized for each target market
- Test screenshots at actual App Store listing size (they appear small on device)

Frequently asked questions about App Store Screenshot Validator

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