The FileReaderSync
interface allows to read File
or Blob
objects synchronously.
This interface is only available in workers as it enables synchronous I/O that could potentially block.
Properties
This interface does not have any properties.
Methods
FileReaderSync.readAsArrayBuffer()
- This method converts a specified
Blob
or aFile
into anArrayBuffer
representing the input data as a binary string. FileReaderSync.readAsBinaryString()
- This method converts a specified
Blob
or aFile
into aDOMString
representing the input data as a binary string. This method is deprecated, consider usingreadAsArrayBuffer()
instead. FileReaderSync.readAsText()
- This method converts a specified
Blob
or aFile
into aDOMString
representing the input data as a text string. The optionalencoding
parameter indicates the encoding to be used (e.g., iso-8859-1 or UTF-8). If not present, the method will apply a detection algorithm for it. FileReaderSync.readAsDataURL()
- This method converts a specified
Blob
or aFile
into aDOMString
representing the input data as a data URL.
Specifications
Specification | Status | Comment |
---|---|---|
File API The definition of 'FileReaderSync' in that specification. |
Working Draft | Initial definition. |
Browser Compatibility
The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
FileReaderSync | Chrome Full support Yes | Edge Full support 12 | Firefox Full support 8 | IE Full support Yes | Opera Full support Yes | Safari Full support Yes | WebView Android Full support Yes | Chrome Android Full support Yes | Firefox Android Full support 8 | Opera Android Full support Yes | Safari iOS Full support Yes | Samsung Internet Android Full support Yes |
readAsArrayBuffer | Chrome Full support Yes | Edge Full support 12 | Firefox Full support 8 | IE Full support Yes | Opera Full support Yes | Safari Full support Yes | WebView Android Full support Yes | Chrome Android Full support Yes | Firefox Android Full support 8 | Opera Android Full support Yes | Safari iOS Full support Yes | Samsung Internet Android Full support Yes |
readAsBinaryString | Chrome Full support Yes | Edge Full support 12 | Firefox Full support 8 | IE Full support Yes | Opera Full support Yes | Safari Full support Yes | WebView Android Full support Yes | Chrome Android Full support Yes | Firefox Android Full support 8 | Opera Android Full support Yes | Safari iOS Full support Yes | Samsung Internet Android Full support Yes |
readAsDataURL | Chrome Full support Yes | Edge Full support 12 | Firefox Full support 8 | IE Full support Yes | Opera Full support Yes | Safari Full support Yes | WebView Android Full support Yes | Chrome Android Full support Yes | Firefox Android Full support 8 | Opera Android Full support Yes | Safari iOS Full support Yes | Samsung Internet Android Full support Yes |
readAsText | Chrome Full support Yes | Edge Full support 12 | Firefox Full support 8 | IE Full support Yes | Opera Full support Yes | Safari Full support Yes | WebView Android Full support Yes | Chrome Android Full support Yes | Firefox Android Full support 8 | Opera Android Full support Yes | Safari iOS Full support Yes | Samsung Internet Android Full support Yes |
Service workers support | Chrome No support ? — 59 | Edge ? | Firefox No support ? — 61 | IE No support No | Opera No support ? — 46 | Safari No support No | WebView Android No support ? — 59 | Chrome Android No support ? — 59 | Firefox Android No support ? — 61 | Opera Android No support ? — 43 | Safari iOS No support No | Samsung Internet Android No support ? — 7.0 |
Available in workers | Chrome Full support Yes | Edge Full support 12 | Firefox Full support 8 | IE Full support Yes | Opera Full support Yes | Safari Full support Yes | WebView Android Full support Yes | Chrome Android Full support Yes | Firefox Android Full support 8 | Opera Android Full support Yes | Safari iOS Full support Yes | Samsung Internet Android Full support Yes |
Legend
- Full support
- Full support
- No support
- No support
- Compatibility unknown
- Compatibility unknown
- Non-standard. Expect poor cross-browser support.
- Non-standard. Expect poor cross-browser support.
- Deprecated. Not for use in new websites.
- Deprecated. Not for use in new websites.