Privacy you can inspect
Watch a file change without leaving your browser
This page measures the network before and after a real 200×200 image resize. It reports what the browser observed instead of asking you to trust a slogan.
Live local test
Resize an image while requests are counted
Use the built-in sample or choose your own image. The browser creates a 200×200 JPEG and compares the number of data-capable requests immediately before and after processing.
Run the test to see the generated image and the measured request difference.
What the measurement proves
File selection, decoding, drawing, encoding and download creation happen through browser APIs. The test records calls initiated through fetch, XMLHttpRequest and sendBeacon before processing, then compares the count after the output exists. A zero difference means the image-processing action added no request capable of carrying the selected file away.
What it does not claim
A web page still downloads HTML, scripts, styles, fonts and optional processing models. Shard Tools also uses AdSense and displays external directory badges, so those services can appear as third-party hosts during page load. The live footer report lists them instead of hiding them. The important distinction is whether handling your file adds another request.
Check it independently
- Open the browser developer tools and select the Network panel.
- Clear the request list, run the sample above, and inspect the requests added afterward.
- Repeat with your own image. The output should appear as a local blob URL, not an upload response.
Server boundary
The Shard Tools Worker accepts only GET, HEAD and OPTIONS requests. Upload-capable methods receive a 405 response. The tool registry separately marks browser-local tools so a page cannot silently declare an upload endpoint while claiming local processing.