Turning photos into pixel art always fascinated me.
But every app I found was expensive, bloated, or filled with ads.
So I built CoffeePixel — simple, beautiful, and 100% offline.
The Initial Spark
Scrolling through Instagram, I kept seeing retro profiles — 8-bit avatars,
NES-style photos, that nostalgic 80s and 90s aesthetic.
Existing apps were either too complex or packed with features I didn’t need.
Why isn’t there an app that does one thing — and does it really well?
The Technical Challenge
Pixel art isn’t just lowering resolution. High-quality results require:
- Limited color palettes
- Smart dithering
- Detail preservation
- Crisp nearest-neighbor scaling
The Stack
Core Image
Core Image is incredibly powerful, but there’s no true pixel art filter
available out of the box.
1. Downscale image
2. Color quantization
3. Optional dithering
4. Nearest-neighbor upscale
5. Edge sharpening
Main Features
Instant Preview
Real-time updates as you adjust pixel size.
Pixel Size Control
From subtle to full retro.
Offline Processing
Your photos never leave your device.
High-Quality Export
Lossless PNG output.
Tech Stack
Swift
SwiftUI
Core Image
UIKit
async/await
iOS 18+
What I Learned
- Image processing is deceptively complex
- Performance is everything
- Less features, more quality
- Offline is a real feature
1.7MBApp size
6Languages
100%Offline
0Ads / Tracking