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🧪 SpriteBrew

AI-powered pixel art sprite sheet generator. Upload or generate characters → animate → slice → preview → export game-ready sheets for Unity, Godot, GameMaker, RPG Maker.

Status: Pre-launch · Active development · Join the waitlist

🌐 spritebrew.com — Try it now (free account required for AI generation)


What is SpriteBrew?

SpriteBrew is a web-based tool for game developers and pixel artists that combines traditional sprite sheet workflows with AI-powered generation. Create new characters from text descriptions, animate existing pixel art, preview animations with keyboard controls, and export to every major game engine — all in one place.

Free tools (no account needed): Upload & Slice, Animation Preview, Multi-Engine Export, Pixel Editor, Pixel-Perfect Resizer

AI features (free account, 5 generations/day): Text-to-Sprite Generation, Animate My Character


Features

🎨 AI Sprite Generation

Describe a character in plain text and get a complete animated sprite sheet. Choose from multiple animation styles including 4-angle walking, walking & idle, small sprites, and VFX. Powered by Retro Diffusion's pixel art models.

🏃 Animate My Character

Upload your existing pixel art character and generate animation frames from it. Walk cycles, idle loops, attacks, jumps, crouches, and destruction animations — the AI preserves your character's appearance while creating smooth motion. Smart animation padding ensures weapons and motion aren't clipped.

🧙 Auto-Prep Character Pipeline

Drop any character image and SpriteBrew handles the rest: contour-based sprite detection, smart cropping, background removal with adjustable tolerance, and pixel-perfect resize to 64×64. Before/after preview with one-click approval. Edit the prepped image in the built-in pixel editor if auto-detection missed something.

✂️ Upload & Slice

Drop any sprite sheet PNG, configure frame dimensions (auto-detect or manual), and slice it into individual frames. Grid overlay preview, multi-select frames, contour-based detection for non-grid layouts, and smart auto-assignment of animation groups with directional detection.

🎮 Animation Preview

PixiJS-powered interactive demo area with full keyboard controls. Walk your character around with arrow keys, trigger attacks with spacebar, and test animations in real-time. Supports 4-directional movement for top-down RPG sprites. Multiple tiled backgrounds (grid, grass, dungeon, stone).

📦 Multi-Engine Export

Export to six formats in one click:

  • TexturePacker JSON Hash (Unity, Godot, general)
  • Aseprite JSON (pixel art workflow)
  • GameMaker horizontal strips
  • RPG Maker MV/MZ 3×4 grid
  • Godot SpriteFrames .tres
  • Raw Frames ZIP (individual PNGs)

🖌️ Pixel Editor

Click any frame to open a zoomed pixel editor. Fix AI artifacts, touch up details, or make manual adjustments. Pencil, eraser, eyedropper, color palette, undo/redo (50 states, Ctrl+Z). Edit at 8-16× zoom with pixel grid overlay and 1× preview alongside.

📸 Generation Gallery

Browse all past generations with filtering (Created vs Animated). Download PNGs, send to slicer, or delete. Per-user history — each account sees only their own generations.

🔐 Authentication

Sign in with GitHub or email. Free tools work without an account. AI generation requires a free login (5 generations/day). Powered by Clerk with production SSO.

📐 Pixel-Perfect Image Resizer

Built-in nearest-neighbor resizing for preparing pixel art for animation. Upload a high-res character, resize to 64×64 with crisp pixel-perfect scaling — no blurry bilinear interpolation.


Tech Stack

Layer Technology
Framework Next.js 16 (React 19)
Styling Tailwind CSS v4
State Zustand
Animation PixiJS 8
Auth Clerk (@clerk/react)
AI Backend Retro Diffusion (direct API + Replicate hosting)
Storage Cloudflare KV
Export JSZip
Hosting Cloudflare Pages
License AGPL-3.0

Architecture Highlights

  • SSE streaming with 15-second heartbeats to work around Cloudflare Pages' 120-second proxy timeout during long AI generations
  • Base64 image pipeline — no URL expiration issues, images cached per-user in generation gallery
  • Per-user daily limits via localStorage with admin bypass for development
  • Waitlist system backed by Cloudflare KV for Pro tier signups
  • Contour-based sprite detection using connected component labeling for non-grid sprite sheets
  • Calibration-driven development — when AI APIs are undocumented, we write targeted calibration scripts to get ground truth

Getting Started (Development)

# Clone the repo
git clone https://github.com/GAlbanese09/spritebrew.git
cd spritebrew

# Install dependencies
npm install

# Set up environment variables
cp .env.example .env.local

Add your API keys to .env.local:

REPLICATE_API_TOKEN=your_replicate_token
RETRO_DIFFUSION_API_KEY=your_retrodiffusion_key
NEXT_PUBLIC_CLERK_PUBLISHABLE_KEY=your_clerk_publishable_key
CLERK_SECRET_KEY=your_clerk_secret_key
# Run development server
npm run dev

Open http://localhost:3000 to see the app.

Note: The waitlist feature requires a Cloudflare KV binding (SPRITEBREW_KV) to work in production. Local development works without it (falls back to in-memory storage).


The Story

SpriteBrew exists because a friend is building a pixel art game and needed sprite sheets. Making them by hand is brutally slow — every frame, every direction, every animation state, hand-drawn. There had to be a better way.

Built by George Albanese — an endpoint automation engineer by day, solo indie developer by night. Built with Claude, session by session, from empty repo to production tool.


Roadmap

  • Phase 1: Web shell, sprite slicer, export engine (6 formats)
  • Phase 2: AI integration (Retro Diffusion)
  • Landing page and waitlist
  • Clerk production auth
  • Visual style picker with live previews
  • Full Retro Diffusion direct API migration (unlocks 40+ styles)
  • Credit system with Stripe integration
  • OpenNext migration (replace deprecated @cloudflare/next-on-pages)
  • Self-hosted AI pipeline (ComfyUI on RunPod)
  • Isometric sprite support
  • Tauri desktop app (Phase 4)

Acknowledgments

  • Retro Diffusion — the AI models that make SpriteBrew's pixel art generation possible. Built by pixel artists, for pixel artists.
  • Clerk — authentication without the pain
  • Cloudflare — Pages, KV, and the infrastructure that keeps this running on a hobby budget
  • PixiJS — the rendering engine behind the animation preview
  • Claude (Anthropic) — architect, research partner, prompt writer, rubber duck
  • George's friend — the reason this exists in the first place [https://github.com/mohammadsalim]

License

AGPL-3.0 — Open source with SaaS protection. You can use, modify, and distribute SpriteBrew, but if you deploy a modified version as a service, you must release your changes under the same license.


Contributing

SpriteBrew is in early development and pre-launch. If you're interested in contributing, please open an issue first to discuss what you'd like to work on. A Contributor License Agreement (CLA) will be required before merging PRs.

Bug reports, feature suggestions, and feedback are welcome via GitHub Issues.


Built with ☕ and Claude · spritebrew.com

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