Web Developer Guide to Amazon's Silk Browser for Fire Tablets

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Amazon’s Fire tablets are some of the biggest selling Android-based tablets. It can be useful to test your sites on the devices built-in Silk browser but information is not widely available. Below I’ve listed a few notes on things I’ve found useful.

About Silk

Amazon’s Silk Browser uses the Webkit browser engine and was launched in 2011. The browser used to perform processing of some web pages on Amazon’s servers to improve webpage loading performance, but this is no longer the case and the option was removed from the browsers UI some time ago. The optimisations were only ever performed on HTTP (not HTTPS) pages, and since most of the web is now on HTTPS the feature became less useful.

Third Party Browsers

Fire tablets don’t have access to the Google Play Store (or any Google services for that matter) and unfortunately no third party browsers are available to install on Fire tablets from the Amazon Appstore. This is odd because browsers such as Opera , Opera Mini are on the Amazon Appstore, but they haven’t been updated for many years and can only be downloaded on non-Amazon tablets by using the Amazon Appstore app.

It’s easy to sideload Firefox (Beta) on a Fire tablet without any hacks using the APK though.

How to find out the Chromium version

Go to Settings > Apps & Notifications > Amazon App Settings > Silk browser > Advanced > About Silk and check the Application version. At the time of writing this was v79.x (Google’s Chrome for Android is currently on v80.x) On HTML5test.com the browser scores 465 (out of 555) which is close to Google Chrome’s 485.

Detect browser via UserAgent

if (/\bSilk\b/.test(navigator.userAgent)) {
  alert("Silk detected!");

The user agent for the 2018 Fire tablet 7" (as of today) is: Mozilla/5.0 (Linux; Android 7.1.2; KFMUWI) AppleWebKit/537.36 (KHTML, like Gecko) Silk/80.5.3 like Chrome/80.0.3987.162 Safari/537.36

Low-DPI screens

Unlike all iPads sold in the last several years, Fire tablets have low-DPI screens . If you’re serving bitmap images, be sure to send 1x images via img or srcset to save bandwidth.

Enter Developer Mode

To enable developer options on the tablet go to Settings > About Fire Tablet and tap on the Serial number several times until it says you’re a developer. This will give you access to a new Developer options menu. From here you can view the WebView implementation engine, allow remote debugging and much more.

Developer Options screenshot on Fire tablet

Amazon’s Web Developer Guide

Amazon have a Web Developer Guide , though a lot of the content is dated.