I’ve always known that certain browsers can be resource hogs, but what I did not fully grasp was how much is hidden beneath the surface. When I suspect my browser is slowing my computer down, the task manager simply offers a single tidy "Chrome.exe." Even browser task managers don’t provide a clearer view. While displaying tabs and extensions, they never expose real activity beneath those labels.

I started using the open-source Glances tool, and instead of compressing important details into a vague category, it shows every subprocess, helper, and background task. After seeing this detailed level of browser activity, I now understand which browsers are truly lightweight, and I’ve broken loose from the filtered version of reality.

Glances: the visibility your browser never gives you

A system-level view of your browser tools quietly avoids

Glances watches your browser as a collection of real system processes, not abstracted "tabs" or "tasks," just the way it watches other applications. It gave me the opportunity to see for the first time how sprawling modern browsers really are. A single tab can spin up several renderer processes, utility processes, a GPU helper, and a networking thread that work in parallel and are typically not shown in your browser’s task view.

This showed me that slowdowns can be triggered by a preloader preparing a page I haven’t opened yet, or a renderer stuck in a loop after a website crashes. Glances shows activity spikes when and where they happen, and doesn’t attempt to interpret or compress any of them.

It shifted my mindset from "my browser is heavy" to "this specific subprocess is misbehaving." I see symptoms unfold in real time, and I don’t have to guess why performance drops. It’s a better, free alternative to the default Task Manager.

Glances

OS Linux, macOS, Windows

Price model Free

Glances is a free, open-source, and cross-platform system monitoring tool. It shows real-time system metrics in a single, easy-to-read interface, allowing you to filter and get a granular understanding of running processes.

The performance picture you never get from browser tools

Where built-in monitors summarize, Glances reveals

Browser task managers simplify what’s happening. Even though they show you CPU percentages and memory numbers, these are a filtered, self-contained view of resource usage that doesn’t represent how these loads behave at the system level. Glances goes the extra mile. I’ve used it to observe disk write storms from pages that aggressively cache offline data. That activity caused severe lag on my system, but never showed up in the browser’s tool.

You even get a clearer picture from observing how a process uses the CPU in Glances. For instance, when a website hits a single core with offscreen scripts or analytics loops, browser tools generally represent it by percentages. Glances, on the other hand, makes the issue granular by revealing actual core saturation.

Glances also brings memory issues into focus. It shows the gradual rise in raw numbers where browser tools make leaky tabs look subtle. Being able to observe a renderer climb from a few hundred megabytes to over a gigabyte helps me know exactly where to intervene before slowdowns begin.

The subtle drains and runaway tasks you’d never know existed

Glances reveals browser behavior that is not technically wrong but still drags down performance. It has shown me tabs that continue running JavaScript even after I’ve minimized them. I’ve also observed video players doing background decoding after being paused. Even though none of these show up in the browser’s task manager, Glances picks up on them instantly.

It sometimes gets worse with extensions, as some trigger idle network checks or CPU-light tasks all day long. Other extensions can keep background handlers running even after closing all browser windows. Glances ensures abnormalities are flagged easily as standout disk I/O patterns, raw CPU ticks, and bandwidth spikes.

Then we have problematic cases, like service workers that refuse to terminate, processes that respawn abandoned connections, and poorly built sites that leak resources and slow everything down. As long as the problem touches your system, Glances catches it even before it becomes noticeable.

Glances for power users: setup and the features that matter

Quick installation, immediate clarity, and deep customization

Glances is very lightweight, which makes it easy to adopt. Once you have Python 3 installed on your computer, you can install it across several platforms (Windows, macOS, Linux) with the command:

pip install --user glances[all]

To launch the tool, run this command on the command prompt: glances. Alternatively, to launch the browser UI:

1. On your terminal, run the command: glances -w
2. Open a browser and visit the URL: http://localhost:61208/. This works similarly to the ttyd Linux tool that turns the terminal into a web session.

At launch, you can start watching your system. However, Glances transforms into a real power tool with customizations. I filter views by process name for a more condensed list. I also highlight CPU or disk spikes with alerts and reorganize the layout to surface only the activity I care about. I routinely isolate browser processes so I can watch them whenever my browser starts behaving oddly, turning the tool into a live debugging window.

It also has a surprisingly helpful remote mode that allows you to run the Glances UI from another device. Using this feature, I can monitor heavy browser sessions without affecting them. I use this if I need to test a stubborn page or extension.

Related

Seeing your browser’s behavior for what it really is

The modern browser comes with a clean interface that hides a lot of activity. It makes it hard to know what may be causing a system lag. Using built-in browser tools, you can’t fully see or understand the chains of helpers and workers created by tabs, but Glances clears the opacity.

However, I find it more compelling than built-in browser tools because of its transparency. There’s no telemetry, no accounts, no hidden analytics. It’s just an all-around better solution for seeing what your browser wouldn’t readily show.