Frequently Asked Questions
Everything you need to know about IMGcon
What is IMGcon?
IMGcon is a free, client-side image optimization tool. It lets you compress, resize, and convert images directly in your browser — no uploads, no server processing, no waiting. Built with HTML5 Canvas API technology, all transformations happen instantly on your device.
How does image optimization work?
IMGcon uses the HTML5 Canvas API to decode your images, apply your chosen settings (quality, max dimensions, format), and re-encode them into the target format. All processing happens in-memory within your browser's JavaScript engine. Choose your output format (WebP, AVIF, JPEG, PNG), adjust the quality slider, set maximum dimensions, and optionally strip EXIF metadata — then click Optimize.
Which image formats are supported?
Input (upload): PNG, JPEG, WebP, AVIF, SVG, BMP, and TIFF. You can also paste images directly from your clipboard.
Output (download): WebP, AVIF, JPEG, or PNG — selectable via the Format selector in the Configuration panel.
Are my images uploaded to a server?
No — absolutely not. IMGcon operates entirely within your browser. Images are loaded into memory via the Canvas API, processed locally, and the optimized result is offered as a direct download. No image data is ever transmitted to any server. The optional backend API only tracks anonymized aggregate statistics (total images processed and total bytes saved) — never the images themselves.
What is the maximum image size?
There is no hard file-size limit, but IMGcon processes images in your browser's memory. Very large images (100+ megapixels or files exceeding 100 MB) may cause performance slowdowns depending on your device's RAM. For typical web images (up to ~20 megapixels), processing is near-instant. You can use the Max Width/Height inputs to downscale large images before processing.
Can I process multiple images at once?
Yes! Drag and drop multiple files, select them via the file browser, or paste them from your clipboard. IMGcon processes each image sequentially using the same configuration settings. Once complete, you can download individual optimized images or use Download Archive to get everything as a single ZIP file.
How do presets work?
Presets let you save your favorite configuration (format, quality, dimensions) for quick recall. Give your preset a name and click Save. Later, click the checkmark icon on any preset to instantly apply its settings. Presets are stored in your browser's localStorage — they persist across sessions but remain on your device.
Is IMGcon free to use?
Yes, IMGcon is completely free. There are no premium tiers, no hidden fees, and no usage limits. Since all processing happens on your device, there are no server costs to offset. Optimize as many images as you want, whenever you want.
Which browsers are supported?
IMGcon works in all modern browsers that support the HTML5 Canvas API and OffscreenCanvas:
Can I use IMGcon offline?
Once the page has loaded, most of IMGcon's core functionality works without an internet connection — image processing is entirely browser-based. The global stats counter and preset sync (if applicable) require connectivity, but optimizing, downloading, and ZIP export all function offline.
Still have questions?
Reach out via info@3ernert.com — happy to help!