---
name: App Store Screenshot Resize
slug: app-store-screenshot-resize
category: DevOps
description: App Store Screenshot Resize prepares and validates screenshots for App Store Connect using current size data from asc and macOS sips. Use it when resizing, stripping alpha, or checking screenshot files before upload.
github: "https://github.com/rorkai/app-store-connect-cli-skills/tree/main/skills/asc-screenshot-resize"
language: Python
stars: 971
forks: 55
install: "npx degit https://github.com/rorkai/app-store-connect-cli-skills/tree/main/skills/asc-screenshot-resize ~/.claude/skills/asc-screenshot-resize"
installs_to: ~/.claude/skills/asc-screenshot-resize
source_path: skills/asc-screenshot-resize/SKILL.md
collection_size: 25
category_size: 798
collection_url: "https://dirskills.com/collections/rorkai/app-store-connect-cli-skills"
added: 2026-08-21T05:14:55.735Z
last_synced: 2026-08-21T05:14:55.735Z
canonical_url: "https://dirskills.com/skills/app-store-screenshot-resize"
---

# App Store Screenshot Resize

App Store Screenshot Resize prepares and validates screenshots for App Store Connect using current size data from asc and macOS sips. Use it when resizing, stripping alpha, or checking screenshot files before upload.

**Install:**

```bash
npx degit https://github.com/rorkai/app-store-connect-cli-skills/tree/main/skills/asc-screenshot-resize ~/.claude/skills/asc-screenshot-resize
```

## README

# 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.