Expo

Documentation

Print

expo-print provides an API for iOS (AirPrint) and Android printing functionality.

Platform Compatibility

Android DeviceAndroid EmulatoriOS DeviceiOS SimulatorWeb
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Installation

For managed apps, you'll need to run expo install expo-print. To use it in a bare React Native app, follow its installation instructions.

API

import * as Print from 'expo-print';

Print.printAsync(options)

Prints a document or HTML.

Arguments

  • options (object) -- A map defining what should be printed:
    • uri (string) -- URI of a PDF file to print. Remote, local (ex. selected via DocumentPicker) or base64 data URI starting with data:application/pdf;base64,. This only supports PDF, not other types of document (e.g. images).
    • html (string) -- HTML string to print.
    • width (number) -- Width of the single page in pixels. Defaults to 612 which is a width of US Letter paper format with 72 PPI. Available only with html option.
    • height (number) -- Height of the single page in pixels. Defaults to 792 which is a height of US Letter paper format with 72 PPI. Available only with html option.
    • markupFormatterIOS (string) -- Available on iOS only. Alternative to html option that uses UIMarkupTextPrintFormatter instead of WebView. Might be removed in the future releases.
    • printerUrl (string) -- Available on iOS only. URL of the printer to use. Returned from selectPrinterAsync.
    • orientation (string) -- Available on iOS only. The orientation of the printed content, Print.Orientation.portrait or Print.Orientation.landscape.

Returns

  • Resolves to an empty promise if printing started.

Print.printToFileAsync(options)

Prints HTML to PDF file and saves it to app's cache directory.

Arguments

  • options (object) -- A map of options:
    • html (string) -- HTML string to print into PDF file.
    • width (number) -- Width of the single page in pixels. Defaults to 612 which is a width of US Letter paper format with 72 PPI.
    • height (number) -- Height of the single page in pixels. Defaults to 792 which is a height of US Letter paper format with 72 PPI.
    • base64 (boolean) -- Whether to include base64 encoded string of the file in the returned object.

Returns

  • Resolves to an object with following keys:
    • uri (string) -- A URI to the printed PDF file.
    • numberOfPages (number) -- Number of pages that were needed to render given content.
    • base64 (string) -- Base64 encoded string containing the data of the PDF file. Available only if base64 option is truthy. It doesn't include data URI prefix data:application/pdf;base64,.

Print.selectPrinterAsync()

Available on iOS only. Chooses a printer that can be later used in printAsync.

Returns

  • Resolves to an object containing name and url of the selected printer.

Page margins

If you're using html option in printAsync or printToFileAsync, the resulting print might contain page margins (it depends on WebView engine). They are set by @page style block and you can override them in your HTML code:
<style>
  @page {
    margin: 20px;
  }
</style>
See @page docs on MDN for more details.