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Blob: slice() method

files/en-us/web/api/blob/slice/index.md

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{{APIRef("File API")}}{{AvailableInWorkers}}

The slice() method of the {{domxref("Blob")}} interface creates and returns a new Blob object which contains data from a subset of the blob on which it's called.

Syntax

js-nolint
slice()
slice(start)
slice(start, end)
slice(start, end, contentType)

Parameters

  • start {{optional_inline}}
    • : An index into the {{domxref("Blob")}} indicating the first byte to include in the new {{domxref("Blob")}}. If you specify a negative value, it's treated as an offset from the end of the {{domxref("Blob")}} toward the beginning. For example, -10 would be the 10th from last byte in the {{domxref("Blob")}}. The default value is 0. If you specify a value for start that is larger than the size of the source {{domxref("Blob")}}, the returned {{domxref("Blob")}} has size 0 and contains no data.
  • end {{optional_inline}}
    • : An index into the {{domxref("Blob")}} indicating the first byte that will not be included in the new {{domxref("Blob")}} (i.e., the byte exactly at this index is not included). If you specify a negative value, it's treated as an offset from the end of the {{domxref("Blob")}} toward the beginning. For example, -10 would be the 10th from last byte in the {{domxref("Blob")}}. The default value is size.
  • contentType {{optional_inline}}
    • : The content type to assign to the new {{domxref("Blob")}}; this will be the value of its type property. The default value is an empty string.

Return value

A new {{domxref("Blob")}} object containing the specified subset of the data contained within the blob on which this method was called. The original blob is not altered.

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}

See also