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Why every Cool Easy extension lives in the Chrome side panel

Every Cool Easy extension opens in Chrome's side panel, not a popup or a new tab. That's a deliberate design choice, and it shapes everything about how the tools work.

The problem with popup extensions

Most Chrome extensions use a toolbar popup — a small window that appears when you click the extension icon and closes when you click anywhere else.

Popups work fine for quick, single-action tools: translate this word, copy this link, run this script. The tool does one thing, you get the result, the popup closes.

They work poorly for tools that need to stay open while you work. If your to-do list is in a popup, you have to re-open it every time you want to check it. If your research pinboard is in a popup, it closes every time you click on the page. The tool can't coexist with your content — it can only temporarily replace your attention.

The side panel solves this. It's a persistent panel that stays open alongside the current tab, visible while you browse, scroll, and interact with pages. You don't lose it when you click.

Why we built everything in the side panel

When we were designing the first Cool Easy extension, the choice between popup and side panel came down to a single question: does this tool need to coexist with what you're working on, or can it work in a burst?

For a to-do list alongside your work, you need coexistence. You need to see the list while you're in a document, a form, or a code editor. A popup that closes every time you click in the page is useless for that use case.

The same logic applies to every tool in the lineup:

The side panel makes all of these feel like tools that live in your workflow rather than interruptions to it.

What it means for local storage

The side panel architecture pairs naturally with local storage. A side panel tool that syncs to the cloud needs to be running a connection in the background, which requires broader permissions and increases complexity.

All Cool Easy extensions store data in Chrome's local extension storage. There's no account, no server connection, no sync. Your data stays on your machine. The side panel can read and write to local storage instantly — no latency, no offline handling required, no privacy concerns about what's being transmitted.

This also means the tools work exactly the same whether you're online or offline, on your home network or a coffee shop's. The browser is the environment; nothing beyond it is needed.

The full Cool Easy lineup

Every extension follows the same pattern: side panel, local storage, no account.

Common questions about side panel tools

"Will it conflict with other side panel extensions?" Chrome only shows one side panel at a time, but each extension independently opens its own panel when you click its icon. They don't conflict — you just switch between them by clicking different toolbar icons.

"Does it slow Chrome down?" Side panel extensions run their code while the panel is open. When closed, they're dormant. The performance impact is comparable to having a pinned tab open.

"Can I use it on every site?" Yes. The side panel is browser-level, not page-level — it opens alongside any tab, including internal Chrome pages.

FAQ

What is Chrome's side panel?

Chrome's side panel is a persistent panel that opens on the right side of the browser window, alongside the current tab. It was introduced as a stable API in Chrome 114 (2023). Extensions that use it can display content that stays visible while you browse — similar to how a sidebar works in a desktop app.

Why don't most extensions use the side panel?

The side panel API is relatively new, and many extensions were built before it existed. Toolbar popups are easier to build and work across more Chrome versions. The tradeoff is that popups close the moment focus moves to the page — which makes them poor fits for tools that benefit from persistent visibility.

Does the side panel take up too much screen space?

The side panel is resizable and can be closed with one click. For most monitors at 1440px+ width, a 300-400px side panel leaves plenty of room for page content. On smaller screens (laptops at 1280px), it's worth thinking about — but the panel closes fully when not needed, so it's only there when you want it.

Do all Cool Easy extensions use the same side panel, or different ones?

Each extension has its own side panel. Chrome allows one side panel per extension, and you open whichever one you want by clicking its toolbar icon. You can only have one side panel open at a time.