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asc-screenshot-resize

Resize and validate App Store screenshots with current asc screenshot-size data and macOS sips.

Skill by rorkai

IndexedMIT★ 1,100
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Works with Claude Code, Claude apps, Codex, Cursor, Gemini CLI, GitHub Copilot, VS Code, OpenCode, Goose, Windsurf. Read the repository before you give any tool access to your data.

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About

Resize and validate App Store screenshots with current asc screenshot-size data and macOS sips. Use when preparing or fixing screenshots for App Store Connect submission.

Use cases: data

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What this skill can do and what it asks for, from its SKILL.md. Checked Oct 25, 2026.

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Network hosts it talks to 1

  • codeload.github.com · found in install command

Files it touches

  • ~/.claude/skills/asc-screenshot-resize

What's inside

Skill name
asc-screenshot-resize
Description
Resize and validate App Store screenshots with current asc screenshot-size data and macOS sips. Use when preparing or fixing screenshots for App Store Connect submission.
License
MIT
Instructions
119 lines in SKILL.md · view on GitHub

Files (1)

  • SKILL.md

SKILL.md (first lines)

# asc screenshot resize

Use this skill to prepare screenshots for App Store Connect. Do not rely on a hard-coded dimension table in this skill; the CLI owns the current size matrix.

## Source of truth

Always discover current accepted sizes from `asc` first:

```bash
asc screenshots sizes --output table
asc screenshots sizes --all --output table
```

For local validation before upload:

```bash
asc screenshots validate --path "./screenshots/iphone" --device-type "IPHONE_65" --output table
asc screenshots validate --path "./screenshots/ipad" --device-type "IPAD_PRO_3GEN_129" --output table
```

Common current device-type anchors:

- `IPHONE_65` for the common 6.5-inch iPhone screenshot set.
- `IPAD_PRO_3GEN_129` for the common 12.9/13-inch iPad screenshot set.

Run `asc screenshots sizes --all` when targeting other display types such as 6.9-inch iPhone, Apple TV, Mac, Vision Pro, iMessage, or Watch.

## Workflow

### 1. Sanitize filenames

macOS screenshots can contain hidden Unicode spaces that make tools fail with "not a valid file". Sanitize before batch work:

```bash
python3 -c "
import os
for f in os.listdir('.'):
    clean = f.replace('\u202f', ' ')
    if f != clean:
        os.rename(f, clean)
        print(f'Renamed: {clean}')
"
```

### 2. Inspect dimensions and metadata

```bash
sips -g pixelWidth -g pixelHeight screenshot.png
sips -g hasAlpha -g space screenshot.png
```

App Store Connect rejects screenshots with alpha transparency. Strip alpha by round-tripping through JPEG:

```bash
sips -s format jpeg input.png --out /tmp/asc-screenshot-no-alpha.jpg
sips -s format png /tmp/asc-screenshot-no-alpha.jpg --out output.png
rm /tmp/asc-screenshot-no-alpha.jpg
```

Batch-strip alpha from PNGs:

```bash
for f in *.png; do
  if sips -g hasAlpha "$f" | grep -q "yes"; then
    sips -s format jpeg "$f" --out /tmp/asc-screenshot-no-alpha.jpg
    sips -s format png /tmp/asc-screenshot-no-alpha.jpg --out "$f"
    rm /tmp/asc-screenshot-no-alpha.jpg
    echo "Stripped alpha: $f"
  fi
done
```

### 3. Resize only after choosing a target from asc

Pick a width and height from `asc screenshots sizes --all`. `sips -z` takes height first, then width:

```bash
# Example: portrait IPHONE_65 1284 x 2778
sips -z 2778 1284 input.png --out output.png
```

Batch resize to a chosen target:

```bash
mkdir -p resized
for f in *.png; do
  sips -z 2778 1284 "$f" --out "resized/$f"
done
```

### 4. Validate outputs with asc

```bash
sips -g pixelWidth -g pixelHeight -g hasAlpha resized/*.png
asc screenshots validate --path "./resized" --device-type "IPHONE_65" --output table
```

### 5. Upload only after validation

```bash
asc screenshots upload --version-localization "LOC_ID" --path "./resized" --device-type "IPHONE_65" --dry-run --output table
asc screenshots upload --version-localization "LOC_ID" --path "./resized" --device-type "IPHONE_65"
```

## Guardrails

- Treat `asc screenshots sizes --all` as authoritative; Apple size requirements change.
- Do not stretch screenshots across incompatible aspect ratios unless the user accepts the visual tradeoff.
- Always output to a separate file or directory to preserve originals.
- Screenshots must be PNG or JPEG and must not include alpha transparency.
- Convert Display P3 or other color spaces to sRGB when needed:

```bash
sips -m "/System/Library/ColorSync/Profiles/sRGB IEC61966-2.1.icc" input.png --out output.png
```

- Prefer `asc screenshots validate` over visual inspection before upload.

From rorkai/app-store-connect-cli-skills, MIT.

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    Stars
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    Forks
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    Open issues
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    Last commit (this folder)
    May 3, 2026 (5 months ago)

    From GitHub (fetched Oct 24, 2026).

    Details

    License
    MIT
    Website
    asccli.sh
    First seen
    Oct 24, 2026
    Last checked
    Oct 24, 2026

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    Cite this page

    asc-screenshot-resize skill. Agent Mart. https://agentmart.dev/skills/rorkai-asc-screenshot-resize (last updated 2026-10-24)