Top 5 - Must Have Browser Extensions for Frontend Developers

Extensions can be great dev tools. If you are not using any then you are probably missing out on opportunities to boost your productivity.

They can be extremely useful when it comes to debugging, fast prototyping and designing.

But some might also assist you with SEO, speed and security of you your website. All of this together combined will make your work just better and more efficient.

Here are five extensions that I use and highly recommend. I hope you’ll find at least 1 that is useful for you as well.

Table of contents

∘ 1) Measure Everything
∘ 2) Web developer
∘ 3) Checkbot
∘ 4) CollorZilla
∘ 4) JSON Formatter
∘ Honourable mentions
∘ Conclusion

1) Measure Everything

Element distance measurement tool

Sometimes elements can be or appear to be slightly off and going through dev tools, paddings, and margin on the right wrapping element is just annoying.

A measuring tool is a no-brainer extension since it can save you so much time .

And for pixel-perfect or near-pixel-perfect designs a measuring tool is a must, in my opinion.

I’ve used some alternatives, like Page Ruler or Dimensions but Measure Everything worked the best for me.

Available for:

• Chrome
• Firefox

Alternatives: Page Ruler , Dimensions

2) Web developer

Adds a toolbar button with various web developer tools

This one I started using recently and I’ve been blown away by the huge amount of options.

It’s just too many of them to list so I’ll give you screenshots of each tab and you can see them for yourself.

1) Disable:

2) Cookies:

3) CSS:

4) Forms:

5) Images:

6) Information:

7) Miscellaneous:

8) Outline:

9) Resize:

10) Tools:

As you can see it has a tool for almost anything you can imagine.

Available for:

• Chrome
• Firefox

3) Checkbot

Seo, speed & security

Checkbot is basically helping you to adhere to best practices in SEO, speed and security. It scans your website, diagnoses it and warns you if something needs your attention and how you can improve it.

Checkbot has a Free and Pro version. 10$/month for yearly sub and 15$/month for monthly.

Companies like Amazon, Accenture, Binance, Discovery Channel, Merric Bank or even WinZip are using it so that doesn’t sound bad to me at all.

Some features are of course only available in the Pro version but the Free version has plenty of features if you want to use it.

This is how I would summarize their features.

Features:

SEO Auditing:

• Identifies common SEO issues: Duplicate titles, invalid HTML, poor mobile usability, broken links.
• Ensures optimization: Meta tags, functional links, and proper page indexing.

Speed Optimization:

• Analyzes website performance: Identifies ways to improve load times.
• Checks for issues: Uncompressed images, slow server responses, and inefficient CSS/JavaScript.
• Recommends improvements: Minifying resources, leveraging browser caching, and eliminating render-blocking resources.

Security Checks:

• Scans for vulnerabilities: Insecure HTTP headers, TLS/SSL issues.
• Provides recommendations: Implementing HTTPS, configuring security headers to prevent XSS and clickjacking.

Here is how the UI looks right after a scan (this is a scan of a Medium landing page).

Not a tool you would be using every single day but it’s definitely good to use before you go to production and then from time to time at least.

Available for:

• Chrome

4) CollorZilla

Advanced Eyedropper, Color Picker, Gradient Generator

One of those extensions that are just nice to have when you need a certain color from somewhere.

Finding that color in styles in dev tools can be annoying and eyedroppers can save you a decent amount of time and nerves.

Features:

• Eyedropper — Get the color of any pixel inside or outside the browser
• Webpage Color Analyzer — Get a color palette for any website
• Various sampling sizes — 1x1, 3x3, 5x5, 11x11 and 25x25 pixels
• Auto copy — Picked colors are copied to clipboard (multiple formats)
• Color History
• Gradient Generator

and some more.

ColorZilla is super easy to use and it has probably all the features you’ll need but also look at some alternatives if you find them more interesting.

Available for:

• Chrome
• Firefox

Alternatives: Color Picker — Eyedropper, Eye Dropper

4) JSON Formatter

Makes JSON easy to read | Open source

Unfortunately, Chrome doesn’t have a built-in JSON formatter so having some formatter is super helpful to have if you are working with JSON in a tab.

JSON Formatter is very easy to use and has probably most features you’ll need.

Features:

• Fast, even on very long JSON pages
• Syntax highlighting
• Collapsible trees
• Clickable URLs
• Dark mode
• Works on any valid JSON page
• Buttons for toggling between raw and parsed JSON

Available for:

• Chrome
• Firefox has a built-in JSON viewer

Alternative: JSON Formatter (has the same name)

Honourable mentions

SuperDev Pro

This is an interesting 14-in-1 tool which basically allows you to manipulate the DOM very easily and seems to be helpful for some rapid prototyping and testing.

It comes with a Free and Pro version which costs $80 for a lifetime licence.

So far I’ve only tried the free version which is not necessarily limited in features but those that seem quite interesting are in pro only.

You can check the demo of all the features on their website.

I’d say SuperDev Pro could be useful if you are a one-man show designing and building the website or for designers so they can see how the design changes affect the live website.

Available for:

• Chrome

Workspaces

Not a dev tool but one that

Conclusion

There are plenty of extensions out there that I haven’t mentioned but these are the ones I use and find interesting.

If you have some cool extensions or alternatives to these listed above share them in the comments for everyone.

I hope you found at least 1 extension that’s going to be helpful to you and makes your life a little bit easier.