Returns the time offset at which a specified time range begins.


startTime = TimeRanges.start(index) 


  • index is the range number to return the starting time for.


A DOMException thrown if the specified index doesn't correspond to an existing range.


Given a video element with the ID "myVideo":

var v = document.getElementById("myVideo");

var buf = v.buffered;

var numRanges = buf.length;

if (buf.length == 1) {
  // only one range
  if (buf.start(0) == 0 && buf.end(0) == v.duration) {
    // The one range starts at the beginning and ends at
    // the end of the video, so the whole thing is loaded

This example looks at the time ranges and looks to see if the entire video has been loaded.


Specification Status Comment
WHATWG HTML Living Standard
The definition of 'TimeRanges.start()' in that specification.
Living Standard Initial definition

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 Last updated by: swimmwatch,