Image Compressor API Response Simulator

An image compressor API response simulatoris a tool that fetches an image from a URL and re-encodes it in multiple formats — JPEG, WebP, and AVIF — to show what an image transformation API would return for each format at a given quality level. It answers the question: "If my image API served this image as WebP instead of JPEG, how much smaller would it be, and how much bandwidth would I save across my traffic?" Our simulator runs entirely in your browser, using the HTML5 Canvas API to encode the fetched image locally without any server-side processing.

1. Enter an Image URL:Paste any publicly accessible image URL into the input field. The URL must be served with CORS headers — most CDNs (Cloudinary, Imgix, Cloudflare Images, Unsplash) support this. Click "Simulate" or try one of the example URLs to get started immediately.
2. Instant Browser-Based Processing: The simulator fetches the image into your browser using a CORS-enabled image request, draws it onto an HTML5 canvas, and re-encodes it as JPEG, WebP, and AVIF at the selected quality level. Everything runs locally — your image data never leaves your device.
3. View Results and Bandwidth Table: See the compressed file size for each format, the percentage savings vs JPEG, and a bandwidth savings table showing how much data you would save per 1K, 10K, 100K, and 1M page views. Download any format output directly from the results.

• File Size per Format: The exact byte size of the image encoded as JPEG, WebP, and AVIF at the selected quality level — the same output your image API would return for each format.
• Savings vs JPEG: The percentage reduction in file size compared to JPEG at the same quality setting — the primary metric for evaluating a format migration.
• Bandwidth per Page View Tier: Total bytes transferred for 1K, 10K, 100K, and 1M page views, assuming one image load per page view. Useful for estimating CDN bandwidth costs.
• Bandwidth Savings: The difference in total bytes between JPEG and WebP/AVIF at each page view tier — the concrete data point for ROI calculations on a format migration project.

The image compressor API response simulator uses the browser's native image loading with crossOrigin="anonymous" to fetch images. This requires the image server to include Access-Control-Allow-Origin: * in its response headers. Most CDNs and image hosting services support this. Direct links to images on social media platforms, private servers, or services that block cross-origin requests will fail with a CORS error. If you encounter a CORS error, try uploading the image to a CDN like Cloudinary or Imgix and using that URL instead.