Chrome Extensions Every Web Developer Should Know

Web development involves constant context switching — between code editors, browsers, DevTools, API testing tools, and documentation. The right Chrome extensions can reduce that friction by bringing essential tools directly into your browser. Here are four free extensions built specifically for web developers.

1. Pesticide for Chrome — CSS Layout Debugging

The problem: You are working on a layout and something is not aligned correctly. You open DevTools, hover over elements one by one, and try to figure out which element has unexpected margins or padding. This works, but it is slow and tedious for complex layouts.

The solution: Pesticide for Chrome overlays colored outlines on every HTML element on the page. With a single keyboard shortcut (Ctrl+Shift+P), you can see the boundaries of every element at once — headers, divs, paragraphs, spans, all of them.

This makes it immediately obvious where elements overlap, where unexpected spacing exists, and how the overall layout is structured. It is especially useful when working with CSS Grid or Flexbox layouts where element boundaries are not visually apparent.

When to use it:

• Debugging alignment and spacing issues
• Understanding unfamiliar layouts in existing projects
• Teaching or learning CSS layout concepts
• Quickly auditing a page's HTML structure

2. What the Font — Web Font Inspector

The problem: You see a font on a website that you want to identify. You could open DevTools, select the element, and dig through the computed styles to find the font-family, size, weight, and other properties. But this is multiple clicks and requires navigating the DOM tree.

The solution: What the Font lets you hover over any text on a page and instantly see its font properties — family, size, weight, line height, letter spacing, and color — all in a clean tooltip overlay.

This is significantly faster than the DevTools approach, especially when you need to check multiple elements or compare fonts across different sections of a page.

When to use it:

• Identifying fonts on client sites or design references
• Verifying that your CSS font rules are applied correctly
• Comparing typography across different pages or sections
• Quick font research without opening DevTools

3. Google PageSpeed Insights Report Recorder — Performance Testing

The problem: Performance testing with Google PageSpeed Insights requires navigating to the PageSpeed site, pasting your URL, waiting for results, and manually tracking scores over time. If you test frequently — which you should during optimization work — this workflow adds up.

The solution: Google PageSpeed Insights Report Recorder reduces the process to a single click. Click the extension icon, and it opens the current page in PageSpeed Insights. After the test completes, the score is automatically saved.

The extension maintains a history of all your test results, displayed as both a line chart (for visual trends) and a table (for details). This makes it easy to see whether your optimization efforts are actually improving performance.

When to use it:

• Running quick performance checks during development
• Tracking performance scores across multiple optimization iterations
• Comparing performance across different pages of a site
• Creating a historical record of performance improvements

4. Edit and Resend — API Request Debugger

The problem: You need to test an API endpoint with different parameters, headers, or request bodies. Typically, you would switch to a tool like Postman or curl, configure the request, send it, and then switch back to the browser. For quick tests during development, this context switch is unnecessary overhead.

The solution: Edit and Resend adds a dedicated tab to Chrome DevTools where you can capture, edit, and resend network requests directly. Select any fetch() or XHR request that the page has made, modify its URL, headers, body, or HTTP method, and resend it — all without leaving the browser.

This is particularly useful for testing edge cases, debugging authentication flows, or verifying that your API handles malformed requests gracefully.

When to use it:

• Testing API endpoints with modified parameters
• Debugging failed requests by tweaking headers or body
• Verifying error handling for different HTTP methods
• Quick API prototyping without setting up Postman

Putting It All Together

These four extensions cover common daily tasks for web developers:

All four are free, lightweight, and designed to integrate into your existing workflow without adding complexity. They do not require accounts, subscriptions, or configuration — install them and they are ready to use.

Browse all our developer and productivity extensions on extension.rocks.