DevTools Tips

In CSS, you can use the prefers-color-scheme media feature (docs) to detect if the user prefers usin... Read more

Progressive Web Apps (PWA) can register themselves to handle URIs with pre-defined or custom protoco... Read more

You've probably already used console.log() in your code to print debugging values to the Console too... Read more

When selecting elements from the page using the inspect tool, the hovered elements get highlighted,... Read more

DevTools comes with tons of keyboard shortcuts. Some are well known (like F12 to open DevTools), but... Read more

The Console is great to write short JavaScript expressions that read from the document or manipulate... Read more

There is a great mode in all major browser developer tools that makes it really easy to test your we... Read more

Debugging JavaScript can quickly get out of hand when you have a lot of code and many functions that... Read more

Sometimes, when debugging JavaScript code in DevTools, you may want to test a quick change and see w... Read more

There's a lot of tools in DevTools already, probably more than you use. But in some cases, you may n... Read more

If you want to use DevTools in another language than English, you can do it across all major browser... Read more

Imagine you evaluate a long expression like $$('*').map(el => Object.values(el.attributes).map(at... Read more

If your website has features that depend on the geographic location of your users, you can test thes... Read more

Sometimes we write CSS code that's entirely valid but has absolutely no effect at all, and this can... Read more

If you type $0 in the Console tool, in any browser, the currently selected DOM node is returned. Thi... Read more

Modern browser DevTools provide a handy tool to inspect and modify CSS animations, CSS transitions,... Read more

A lot of websites these days get covered with overlays and crammed with lots of ads and other things... Read more

Sometimes we need to uniquely identify an element that lacks an identifier, so that it can be refere... Read more

JavaScript often needs references to DOM nodes on the page. Getting a reference is sometimes easy wi... Read more

There are multiple ways to detect and fix color contrast issues with DevTools, but here is a nice on... Read more

Here is a nice tip to quickly empty your cache and refresh the page, in order to test new code chang... Read more

Using the keyboard can be faster than using a mouse in certain cases (and for some people). One such... Read more

You can simulate various different devices from DevTools, to get an idea of how your webpage might r... Read more

DevTools is confusing! There's so much functionality packed in such a small UI. Did you know that Ch... Read more

You can extract all the styles of an element in one go by using the Copy styles feature. No need to... Read more

https://twitter.com/AmeliasBrain/status/1521146127327801345... Read more

CSS cascade layers is a CSS feature that allows web developers to define their CSS styles in multipl... Read more

The Command menu in Edge and Chrome is great. Here is one more thing it can do: https://twitter.com/... Read more

https://twitter.com/ChatterboxDev/status/1506299424712142864 Also learn more about getting the selec... Read more

Sometimes I need a blank canvas to prototype an idea with HTML and CSS. Something outside of the web... Read more

With DevTools you can detect low color contrast issues which is great. But DevTools in Chrome, Polyp... Read more

In Debug popups that appear on hover using JS we described how to pause the debugger to inspect popu... Read more

https://twitter.com/nghuuphuoc/status/1505892172700299268... Read more

A really useful way to position elements on a CSS grid is using the grid-template-areas property. Wi... Read more

Operating systems offer an accessibility feature where the colors shown on the screen are converted... Read more

Most browsers are now able to instantly go back to previously visited pages without having to wait f... Read more

Browser vendors depend on your feedback to build the right tools for you. Without hearing from you... Read more

I often work with large amount of data that I need to go through and gather interesting information... Read more

Low color vision is very common, and your choice of text and background colors can negatively impact... Read more

You know how you can paste a CSS property name or value in the Styles (or Rules) panel? Well, you ca... Read more

If you want to know which element has the focus on the web page at any time, you can use a live expr... Read more

Emulating different devices in the browser is incredibly useful. It gets tricky when you are on a de... Read more

When you're trying to debug something and event listeners on the page keep interfering with what you... Read more

When selecting elements from the page they normally get highlighted on hover and selected on click.... Read more

If you're feeling adventurous and want to write longer pieces of code in the Console to execute more... Read more

If you want to download all of the images on a webpage in one go, you can use the following few line... Read more

When you're investigating a bug where the backend you connect to doesn't respond with the right thin... Read more

How do certain CSS properties apply to the page isn't always an easy question to answer. While some... Read more

Do you use a CSS-in-JS framework? If so, you know how frustrating it can be to copy CSS from DevTool... Read more

If the inspected web page is long with a lot of elements, and its DOM tree is big and complex, it's... Read more

Taking a photo of a mobile device or tablet is daunting as you have to deal with fingerprints, glare... Read more

In Firefox, Chrome, Polypane and Edge DevTools, you can screenshot a single node from the page. Go... Read more

Using the console of DevTools you can to log some information to debug your JavaScript. The common w... Read more

Moving panels around the user interface can be very useful to make DevTools more unique to you and a... Read more

You can use special formatters in the console.log function to format logs just the way you want. Us... Read more

If you use :hover, :active, and other such pseudo-classes in CSS, you can actually simulate these st... Read more

Do you find the UI of DevTools too small to comfortably work with? Because this UI is made of HTML a... Read more

See your page in 3 dimensions to quickly find out how deeply nested it is, fix z-index stacking issu... Read more

Using the Console of DevTools to log information that changes a lot is a bad idea. First of all, you... Read more

When playing with styling or layout code in DevTools, it's useful to be able to change widths, margi... Read more

If you spent time changing CSS in DevTools, either in the Rules panel (in Firefox), or in the Source... Read more

There is a command menu in Edge and Chrome that allows you to quickly access many different features... Read more

DevTools supports 2 ways to evaluate XPath expressions to help you locate elements in the page. All... Read more

If you want to use a DOM node from the page in the console: Right-click the node in the Elements (o... Read more

Using the console to log some information is a very common way to debug your JavaScript. But you can... Read more

Have you ever been frustrated because you couldn't style a popup or tooltip that appeared on hover?... Read more

You can use the monitorEvents global function in the Console panel to log all of the events dispatch... Read more

If you don't remember the CSS syntax for the box-shadow property (and who does!), then Chrome and Ed... Read more

If you want to hide scripts and other resources loaded by browser extensions in the Network panel, u... Read more

CSS custom properties (also called variables) are very useful to avoid repeating values in CSS, like... Read more

If you want to know what JavaScript code removes, adds, or modifies a DOM element in the page, you c... Read more

Colors in CSS can be expressed in a number of different formats: keyword (e.g. blue), RGB, HSL, hexa... Read more

Chrome, Firefox and Safari all have a light and dark theme for their DevTools. Edge not only has tho... Read more

The periodic background sync API, available to PWAs is a great way to fetch new content while the us... Read more

Edge has an accessibility tab within the elements panel that, among other things, lets you visualize... Read more

The various resources loaded by your site aren't always guaranteed to reach your users when they vis... Read more

When creating or modifying a design prototype for the web, you may want to quickly edit content in t... Read more

Have you ever wanted to know what caused a specific DOM node or element to be created in the page? W... Read more

While you may develop your website on a fast network connection at home or at work, your users may n... Read more

You can easily copy an element's XPath expression from DevTools. This is useful if you need this exp... Read more

Font CSS properties such as font-size, line-height or letter-spacing can be expressed in multiple di... Read more

If you want to learn more about what other tools exist in a browser, or what features a given tool p... Read more

If you need to move nodes or elements around in the DOM tree, to re-order things in the page, you ca... Read more

This is not really a tip, but rather an interesting thing to be aware of when debugging JavaScript.... Read more

Being able to sample colors from the page is super useful. Firefox, Edge and Chrome all allow you to... Read more

The console.log output can be styled in DevTools using CSS. console.log('%c Hello World', 'color: or... Read more

With HTML, you can add alternative text to images using the alt attribute. It can be used to add a t... Read more

Simple, yet powerful, * { outline: 1px solid red; } is a useful debugging trick that helps understan... Read more

$ and $$ are 2 functions you can use in the console to find elements in the page. They are essential... Read more

By default, the messages displayed in the console get removed as soon as you refresh the page (or na... Read more

People who visit your web pages may have different types of color vision deficiencies that, if you i... Read more

In CSS, several different properties use angle unit values, such as the rotate() function of a trans... Read more

The console panel supports a very handy copy() function that stringifies and copies anything you pas... Read more

If you selected an element in the Elements panel (in Chrome, Safari, Polypane or Edge) or the Inspec... Read more

Chrome and Edge both have a visual editor useful for tweaking flexbox and grid alignment properties.... Read more

In Edge, Polypane and Chrome, whenever you use the element selector and hover over elements in the p... Read more

The Network panel lets you filter requests by status code, or mime type, and more. Click in the fil... Read more

When logging performance.timing events to the console, they appear in alphabetical order since they... Read more

Sometimes, the JavaScript code that runs on a website is minified and really hard to read. This is c... Read more

When you want to know which elements a given CSS rule will apply to, in addition to the currently se... Read more

You can expand all descendants under a given DOM node in one go, to avoid having to expand each node... Read more

If you prefer to use console.log() statements rather than the JavaScript debugger because you find i... Read more