: Use performance.now() for sub-millisecond precision. Fetch the Resource : Use the Fetch API to download the file. End the Timer : Record the time immediately upon completion.
: Speed = (Size in Bits / Time in Seconds) . You can then convert this to Mbps. javascript detect speed
const start = performance.now(); // Run your code here const end = performance.now(); console.log(`Execution time: ${end - start} ms`); Use code with caution. Copied to clipboard : Use performance
