Published on June 16th, 2020
Written by Swapnil Bhalode, Co-Founder and CTO of Tala Security

Slow websites lose customers and hurt conversions. Fortunately, you don’t have to sacrifice performance for security, says Tala CTO Swapnil Bhalode.


Whether you’re a webmaster or a marketer, you know how important website performance is. Your users want a fast experience and if there’s too much friction, they’ll move on:

  • The BBC lost 10% of users for every additional second their site took to load.
  • 47% of users expect a website to load in two seconds; 40% will abandon it altogether if it takes longer than three.
  • 79% of users wouldn’t return to a site that had previously performed poorly for them.

The problem is, you also need to secure your website and protect your users from attacks like Magecart and other data theft - because if their credit card is skimmed via your site, they won’t be coming back again either. Running large numbers of third-party scripts and applications slows down website performance, but some web security solutions can have a similar impact: for example, JavaScript-based solutions faced with large numbers of APIs on a webpage can cause significant performance degradation.

Some solutions attempt to mask latency aspects such as Time to First Byte by working asynchronously or splitting the JavaScript into multiple files. The real issue, however, is what the JavaScript itself is doing in the browser and client machine; how long is it taking for content to render on the page and become responsive, enabling the user to genuinely interact. JavaScript runs even more slowly on mobile devices - no platform other than Apple is optimized for it. There are other metrics to consider, too, including first interactive and first CPU idle...

Think about it: when a page opens in a browser, large numbers of APIs are provided, often 200 or more. To be truly comprehensive and secure, a JS-based web security solution has to hook into all of those APIs. All of them. From a performance perspective, you’re now running in synchronous blocking mode - nothing else runs or loads until this hooking is complete, effectively making this process a single point of failure for your website. And to cap it all, the solution itself is providing a hook for attack: if even one API is missed, the door is open. You can read more about the performance penalties of JavaScript insertion here.

Measuring up

To measure how your JS-based security impacts your web page loading performance, you can use Google Lighthouse Tool. The reasons behind the degraded performance you’ll notice include:

● JS protection code must load first in a synchronous manner. i.e. your webpage’s loading is blocked until the JS code has loaded first.

● Typically, JS-based solutions use Sync XHR to load policy configurations (and loading policy configuration after loading without adequate security controls, can itself be a security issue) Again, this blocks page rendering. Google is working on blocking sync XHRs, for all the good reasons, making this feature of your JS-based security solution problematic.

If you’re using a JS-based security solution, you’re likely to see the following error in Chrome’s console tab:

code snip

(Note: this warning will be pointed to the JS file either directly or within the call stack)

It doesn’t have to be this way

No one is going to abandon JavaScript and the rich web experience it enables any time soon. The good news is, you don’t have to degrade your website’s performance at all to secure it. The same experts who developed the powerful in-browser functionality we love to use also developed powerful tools to secure that experience. And because they’re browser-native, they’re designed to work without impacting website performance: Think CSP, SRI, HSTS, Referrer Policy, Feature-policy, Trusted Types and Clear-Site-Data.

Who wouldn’t want to secure their websites with standards developed by the best minds in the business? Vetted and monitored by organizations like W3C and leading figures in the web security community.

Tala’s security policies are directly consumed by the browser - in other words, it becomes part of the native implementation itself, meaning there’s never any performance degradation to the page loading. Tala’s innovative solution ensures that all types of client-side attacks are prevented in real time, without impacting website performance. We do this by automating standards-based security, natively available in every modern browser. This means no overhead and no impact on website performance. Request your free demo today and see how you can make security work with your website performance goals.


Swapnil Bhalode, Co-Founder and CTO of Tala Security

Swapnil Bhalode, Co-Founder and CTO of Tala Security

Swapnil is the Tala’s Chief Technology Officer. Swapnil had over 14 years of experience in researching and building security technologies. Swapnil started his career as a Security Consultant at Ernst & Young, followed by an extensive work in the threat research and response teams at Microsoft, Symantec and Dell. Swapnil holds Master Degree in Computer Science from Syracuse University, and Bachelor’s degree in Computer Engineering from University of Mumbai.

Find Swapnil on LinkedIn


Sign up for our Newsletter

Hand-picked security content for security professionals.