Skip to content
Branch: master
Find file History
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Type Name Latest commit message Commit time
Failed to load latest commit information.

Android Components > Browser > Errorpages

Responsive browser error pages for Android apps.


Setting up the dependency

Use Gradle to download the library from (Setup repository):

implementation "org.mozilla.components:browser-errorpages:{latest-version}"

Quick Start

If you have an ErrorType already at hand, and you want to generate an error page for it with the default template:

val errorType: ErrorType = ErrorType.Unknown
ErrorPages.createErrorPage(context, errorType)

// OR

ErrorPages.createErrorPage(context, errorType, R.raw.custom_html, R.raw.custom_css)

If you want to use your own custom HTML template, make sure that you have the following attributes within percentage values (%) added to your document so that they can be populated by the engine:

  • pageTitle - Title of the page.
  • css - The location of where to place the CSS contents in the document.
  • messageShort - A one line description of the error message Gecko and System engines map their respective error codes to the ErrorType values.
  • messageLong - A more detailed message about the error that was seen.
  • button - Button text that can be clicked on. This is commonly used to reload the page.

For example, here is an HTML error page that will have only a title, short message and some CSS:

<!DOCTYPE html>
        <meta name="viewport" content="width=device-width; user-scalable=false;" />
            <h1 class="errorTitleText">%messageShort%</h1>

Error Pages are also mostly used along with the RequestInterceptor, which can be added to an Engine's Settings:

val settings = DefaultSettings(
    requestInterceptor = RequestInterceptor {
        override fun onErrorRequest(
            session: EngineSession,
            errorType: ErrorType,
            uri: String?
        ): RequestInterceptor.ErrorResponse? =
             RequestInterceptor.ErrorResponse(ErrorPages.createErrorPage(context, errorType))

See the ErrorType enum for the full list of supported error types.

Engine Support

If you want to add support for another engine, you need to support the RequestInterceptor and have it invoked with an ErrorType based on the EngineSession's' error code for that request:

class CustomEngineSession(val interceptor: RequestInterceptor) : EngineSession {
    override onError(errorCode: Int, uri: String) {
        val errorType = when (errorCode) {
            1..5 -> ErrorType.ERROR_SECURITY_SSL
            else -> ErrorType.ERROR_OFFLINE
        interceptor.onErrorRequest(session, errorType, uri)


This Source Code Form is subject to the terms of the Mozilla Public
License, v. 2.0. If a copy of the MPL was not distributed with this
file, You can obtain one at
You can’t perform that action at this time.