Verifies an evidence pack entirely on this device. No network request is made for any check below — this page works with your browser offline. The one exception is the optional Bitcoin-block check at the bottom, which you trigger explicitly.
Drop an evidence pack (.zip) here, or click to choose a file.
Nothing leaves this browser tab. You can disconnect from the internet before doing this.
The OpenTimestamps anchor above is checked structurally without any network call. To confirm it against an actual Bitcoin block header, this button makes a network request — press it only if you want that.