AbstractRange: startOffset property - Web APIs | MDN

AbstractRange: startOffset property - Web APIs | MDN
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AbstractRange: startOffset property
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The read-only
startOffset
property of the
AbstractRange
interface returns the offset into the start node of the range's start position.
To change the start position, use the
Range.setStart()
method or a similar one.
Value
An integer value indicating the number of characters into the
Node
indicated by
startContainer
at which the first character of the range is located.
If the
startContainer
is a
Node
of type
Text
Comment
, or
CDATASection
, then the offset is the number of characters from the start of the
startContainer
to the boundary point of the range. For other
Node
types, the
startOffset
is the number of child nodes between the start of the
startContainer
and the boundary point of the range.
Example
js
const range = document.createRange();
range.setStart(startNode, startOffset);
range.setEnd(endNode, endOffset);

const startRangeOffset = range.startOffset;
Specifications
Specification
DOM
# ref-for-dom-range-startoffset①
Browser compatibility
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This page was last modified on
Jan 24, 2026
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