Flask-ImageKit

Image optimization for Flask. Reduces 5MB uploads to ~200KB.

What it does

• Creates 6 optimized variants per upload (JPEG + WebP for 3 sizes)
• EXIF auto-orientation
• Progressive JPEG encoding
• Aggressive compression without visible quality loss

Built while working on wallmarkets.

Installation

pip install flask-imagekit

Usage

from flask import Flask, request
from flask_imagekit import ImageOptimizer

app = Flask(__name__)
app.config['UPLOAD_FOLDER'] = 'static/uploads'

optimizer = ImageOptimizer(app)

@app.route('/upload', methods=['POST'])
def upload():
    result = optimizer.save_product_image(request.files['image'])
    
    if result.get('success'):
        return {'url': result['image_path']}
    
    return {'error': result.get('error')}, 400

Output

For each image, you get 6 variants:

• thumbnail (150x150): ~5-10KB JPEG
• thumbnail_webp: ~3-7KB WebP
• small (400x400): ~20-40KB JPEG
• small_webp: ~15-30KB WebP
• medium (800x800): ~80-150KB JPEG
• medium_webp: ~50-100KB WebP

Total: ~200KB vs original 5MB

Configuration

app.config['UPLOAD_FOLDER'] = 'static/uploads'
app.config['MAX_CONTENT_LENGTH'] = 5 * 1024 * 1024  # 5MB
app.config['ALLOWED_EXTENSIONS'] = {'png', 'jpg', 'jpeg', 'gif', 'webp'}

Template usage

<picture>
    <source srcset="{{ product.image_webp }}" type="image/webp">
    <img src="{{ product.image }}" alt="{{ product.name }}" loading="lazy">
</picture>

License

MIT

Contributing

Pull requests welcome. Please add tests.