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  1. [ References  ](/en-US/docs/Web)
  2. [ Web APIs  ](/en-US/docs/Web/API)
  3. [ FileReaderSync  ](/en-US/docs/Web/API/FileReaderSync)

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##  In this article

  * Constructor 
  * Instance properties 
  * Instance methods 
  * Specifications 
  * Browser compatibility 
  * See also 

  1. **[ File API ](/en-US/docs/Web/API/File_API) **
  2. **_[ ` FileReaderSync ` ](/en-US/docs/Web/API/FileReaderSync) _ **
  3. Constructor 
    1. [ ` FileReaderSync() ` ](/en-US/docs/Web/API/FileReaderSync/FileReaderSync)
  4. Instance methods 
    1. [ ` readAsArrayBuffer() ` ](/en-US/docs/Web/API/FileReaderSync/readAsArrayBuffer)
    2. [ ` readAsBinaryString() ` ](/en-US/docs/Web/API/FileReaderSync/readAsBinaryString) Deprecated 
    3. [ ` readAsDataURL() ` ](/en-US/docs/Web/API/FileReaderSync/readAsDataURL)
    4. [ ` readAsText() ` ](/en-US/docs/Web/API/FileReaderSync/readAsText)
  5. Related pages for File API 
    1. [ ` Blob ` ](/en-US/docs/Web/API/Blob)
    2. [ ` File ` ](/en-US/docs/Web/API/File)
    3. [ ` FileList ` ](/en-US/docs/Web/API/FileList)
    4. [ ` FileReader ` ](/en-US/docs/Web/API/FileReader)

##  In this article

  * Constructor 
  * Instance properties 
  * Instance methods 
  * Specifications 
  * Browser compatibility 
  * See also 

#  FileReaderSync

**Note:** This feature is available in [ Web Workers ](/en-
US/docs/Web/API/Web_Workers_API) .

The **` FileReaderSync ` ** interface allows to read [ ` File ` ](/en-
US/docs/Web/API/File) or [ ` Blob ` ](/en-US/docs/Web/API/Blob) objects
synchronously. This interface is [ only available ](/en-
US/docs/Web/API/Web_Workers_API/Functions_and_classes_available_to_workers) in
[ workers ](/en-US/docs/Web/API/Worker) as it enable