index.md

---

title: i18n.getMessage()
slug: Mozilla/Add-ons/WebExtensions/API/i18n/getMessage
page-type: webextension-api-function
tags:
  - API
  - Add-ons
  - Extensions
  - Method
  - Non-standard
  - Reference
  - WebExtensions
  - getMessage
  - i18n
browser-compat: webextensions.api.i18n.getMessage

---

{{AddonSidebar()}}

Gets the localized string for the specified message.

See the Internationalization page for a guide on using this function.

Syntax

browser.i18n.getMessage(
  messageName,  // string
  substitutions // optional any
)

Parameters

• messageName

  • : string. The name of the message, as specified in the messages.json file. If the message can't be found in messages.json:

    • Firefox returns "" and logs an error.

    • Chrome returns "" and does not log an error.

• substitutions {{optional_inline}}

  • : string or array of string. A single substitution string, or an array of substitution strings.

    In Chrome, if you supply more than 9 substitution strings, getMessage() will return undefined.

Return value

string. Message localized for current locale.

Browser compatibility

{{Compat}}

Examples

Get the localized string for "messageContent", with target.url substituted:

let message = browser.i18n.getMessage("messageContent", target.url);
console.log(message);

This would work with a _locales/en/messages.json file containing:

{
  "messageContent": {
    "message": "You clicked $URL$.",
    "description": "Tells the user which link they clicked.",
    "placeholders": {
      "url" : {
        "content" : "$1",
        "example" : "https://developer.mozilla.org"
      }
    }
  }
}

If target.url is "https://developer.mozilla.org", then the value of message, in the "en" locale, would be:

"You clicked https://developer.mozilla.org."

{{WebExtExamples}}

Note: This API is based on Chromium's chrome.i18n API. This documentation is derived from i18n.json in the Chromium code.