Setting the Stage
Ever wondered why the features your favorite product promises often take longer than planned? Or why it sometimes feels like engineers deliver more promises than features? Considering how disappointing it feels, experiencing both sides of that letdown has taught me how crucial it is to deliver on time and with high quality.
Developer tooling is one of the core elements that impact delivery speed. The capacity of a developer is enhanced by great tools, such as the many hands of modern AI-powered workflows that enable us to accomplish more with less effort.
For frontend engineers, a core metric of their efficiency in replicating designs is how it looks on laptops, tablets, mobile devices, and large monitors: a phenomenon known as responsiveness. To achieve this, we define breakpoints: width thresholds that tell our layouts when to adapt.
Here's the catch, though: during implementation of a design, browser debugging tools don’t show which breakpoint is currently active. Developers have to cross-check window widths or manually inspect styles, a tiny task that makes each design review and QA cycle longer than necessary. This desire to maximize the efficiency of determining breakpoints sparked the inspiration to build Breakpoint Overlay: a small, yet effective widget that provides real-time responsiveness transparency.
From Frustration to Functionality
Once this gap was verified, I started looking for a way to increase productivity without interfering with my workflow. I wanted a tool that would be easy to use and integrate into my current workflow. Upon exploring existing options, it became clear that most required installing an entirely new browser just to work. That felt excessive. Switching tools comes with steep learning curves and uncertain trade-offs, so I aimed for minimal change and maximum impact.
That realization inspired me to build one myself, not just for me, but for others who care about speed, precision, and simplicity.
Once I had a clearer sense of how the tool should integrate, the next challenge was figuring out what it should feel like. I experimented with modal, sidebar, and persistent panel presentation models, but none of them felt light enough. I eventually settled on a badge overlay, a tiny, unobtrusive widget that quietly lives on top of your project without altering its flow.
The badge uses soft, muted colors to stay out of the way visually. In its collapsed state, it shows the active breakpoint, viewport size, and screen density. When expanded, it reveals a full list of user-defined breakpoints, a compact, focused display that respects the project’s aesthetic while delivering just enough information at a glance.
Once the design direction was set, I outlined functionality that would make it genuinely useful, not just visually informative. A small example is a keyboard shortcut to toggle the overlay’s imperative handlers, allowing developers to show or hide it instantly during workflow.
After settling on the idea and features, I turned my attention to the implementation specifics, which are what make a tool either a habit or a toy. In any setting, I wanted Breakpoint Overlay to be portable, dependable, and simple to use. A few guiding principles shaped this stage:
Core Concepts
- Zero dependencies: Keeping it dependency-free ensures the widget stays lightweight and avoids conflicts within complex build chains.
- Modularity: Each slice of implementation manages a distinct task, creating a unified system that is simple to test and expand.
- Layered testing: To guarantee that its behavior continuously complies with design intent, each significant module has specific test coverage.
Key Technical Decisions
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Resize Event vs. ResizeObserver: ResizeObserver does not alert users when the viewport height changes, despite being excellent for tracking content changes. To address this, I used a throttled
window.resizehandler, ensuring reliable breakpoint detection without performance loss. - Shadow DOM: Style and DOM leaks are common when multiple scripts share the same document tree. To avoid unintended collisions and maintain strict encapsulation, the widget renders inside its own Shadow DOM.
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requestAnimationFrame: For smooth and efficient updates, the overlay throttles resize computations using
requestAnimationFrame. Older updates are cancelled so the tool always reflects the most recent screen state, a simple but powerful performance win.
Each of these decisions reflects the same philosophy that started the project: efficiency through empathy, both for the developer’s workflow and the product’s integrity.
Reflections and Learnings
Charting unfamiliar territory always comes with unique challenges. Determining the minimum viable product (MVP) was a persistent problem for Breakpoint Overlay, just like similar projects.
The idea started simple: track the active breakpoint. But my curiosity got the better of me; I continued to experiment, adding other "cool-to-have" features, reporting container queries, and highlighting overflowing content. New user-experience choices, implementation specifics, and testing considerations arose with every addition. This pursuit for perfection can lead to an unending cycle of development, as was soon discovered.
Snapping out of that obsession was one of the most important lessons of the project. I discovered how to deliver a minimal version that addressed the correct issue first and to put impact ahead of complexity.
Beyond scoping features, there were challenges rooted in unfamiliar technologies. Setting up the project as a monorepo, a single repository managing multiple applications and their dependencies, was new to me. While leaving room for upcoming additions like documentation and integration examples, it was crucial for separating the widget's package, demo app, and configuration files.
These conflicting moments served as stepping stones. Every obstacle revealed a learning gap, and each gap led me back to documentation, community forums, AI research tools, and the open web—a reminder of how collaborative modern development really is.
Looking ahead, I envision Breakpoint Overlay evolving beyond its current functionality. Consider innovative adapters for popular design systems or a movable widget that can be positioned in any viewport corner. More than features, though, this project taught me that building well is about knowing what really matters and not just about adding more.
In the end, Breakpoint Overlay became more than a tool. It became a reflection of curiosity, restraint, and the constant pursuit of better ways to build.
Closing Thought
Every line of code in Breakpoint Overlay carries a lesson about design empathy, deliberate constraint, and the quiet power of developer tools.
Because sometimes, innovation isn’t about doing more; it’s about making what you already do feel effortless.
If you’ve ever wished for a simpler way to see which breakpoint your app is using, check out Breakpoint Overlay.
It’s open source, dependency-free, and available on both GitHub and npm. Feedback, suggestions, or contributions would be greatly appreciated, especially from engineers who share my passion for the developer experience.
Top comments (34)
You didn’t just build a random dev tool, you solved an actual everyday irritation in a way that fits into day-to-day workflow. The decisions around Shadow DOM, rAF, and staying dependency-free show you were thinking long term and not just hacking stuff together.
Developers who care about DX will understand the value of this immediately. Nice work!
Thank you so much my mentor, @bashy_io
I am glad you find this impressive!
This is actually awesome !!!
Thank you so much, you should consider testing it out and share your feedback too @varshithvhegde
Sounds like a great tool 🔥
However what I appreciated most about this article is the description of your choices and mindset. This is a great mentoring piece!
So many folks would only concentrate on the tool & tech chosen. Not why they were chosen.
Kudos!
Thank you for such an elaborate and kind feedback @john_harding_0d8e406f9b04
You did a great job
That is so kind of you @web_dev-usman
If you can, please share whatever improvements you think I need to make.
Hey bro, I'm sure you have noticed series increase in your views, because I have shared this ink with my squad
.
Thank you so much, @web_dev-usman
I really appreciate the gesture :)
Nice one! I code on mobile, so I’m wondering — will it support mobile users too? 🤗
Good work, @olawalethefirst.
Thank you @automatic_9a1a5b02ba0d308
I am curious, what do you mean by 'code on mobile'? But just so you know, as long as your application runs in the browser, this tool can be integrated into your framework.
I code directly on my phone using [Acode editor]. Cool to know it integrates with any browser-based framework — thanks for the clarification!
Just enable "Show media queries" in Chrome DevTools...
Oh, I agree you can do this @feketegy but it doesn't give a named definition of the media queries or the currently active query that our app configuration specifies. A value that breakpoint-overlay provides at its core.
Very interesting to read, amazing work
Thank you for dropping a review @nadeem_rider
I really do appreciate it.
awesome
Thank you @maulikevince
I don't understand the theme of your post but thanks for sharing it🥰
I am sorry you don't; @00rvn00
The summary of the write-up is: I developed a tool to make frontend developers more effective at their job.
This is a very interesting thought and implementation. I like the fact that you are settling for a badge overlay. And I can't wait to see this in its functional state
Thank you @cecey_diamond_a085cea65ba
You can check it out in its functional state by cloning a live example in the github repository. Thank you so much for your once again!