Install a Chrome Extension From a ZIP (No Unzipping)

CRX Starter Team · Updated Oct 31, 2026 · 5 min read

Short answer

Chrome can’t install a Chrome extension from a ZIP directly; the standard route is to unzip it, turn on Developer Mode and click Load unpacked. With CRX Starter you skip all three: drop the .zip into the CRX Starter workbench, read the check, and click Allow and install. The ZIP must contain a Manifest V3 manifest.json.

Shelf Notes is a small side-panel notebook that its author only publishes on GitHub. There’s no store listing — just shelf-notes-0.9.2.zip on the Releases page. Chrome has no "install from ZIP" button, so the usual instructions start with "unzip it and turn on Developer mode".

You don’t need to. Here’s how to install the ZIP as it is, and see what it asks for before it runs.

Transcript

01This extension only ships as a ZIP on GitHub.
02The usual way is to unzip it, turn on Developer Mode, and load it unpacked. Here's a shorter way.
03Download the ZIP from the Releases page, not the source code.
04Don't unzip it. Drop the ZIP into CRX Starter.
05It only keeps its own settings. No sites, no browser features.
06Allow and install. Then open Chrome's side panel and pick CRX Starter: Shelf Notes is there.
07New release? Drop the new ZIP in. CRX Starter asks before replacing.
08CRX Starter. Read first, then install.

On this page

What you need
Steps
Which ZIP to download from GitHub
The Load unpacked way, for comparison
Updating to a new release
Questions

What you need

The extension’s .zip from the Releases page — not "Source code (zip)"
Chrome 120 or later
CRX Starter, free from the Chrome Web Store

Steps

1
Download the right ZIP
On the project’s GitHub Releases page, open the latest release and look under Assets. Download the file the author built for installing — here, shelf-notes-0.9.2.zip. The two "Source code" archives GitHub adds to every release are the raw repository, and often need a build step before they are an extension.
2
Open the CRX Starter workbench
Click the CRX Starter icon in the toolbar, then Open workbench. If you haven’t added CRX Starter yet, add it from the Chrome Web Store first — it takes a few seconds.
3
Drop the ZIP — don’t unzip it
Drag the .zip onto the slot, or click Choose file. CRX Starter looks for manifest.json inside the archive, including one folder down, which is how many release ZIPs are packed. If there isn’t one, you’ll see "This isn’t an extension package" and nothing is installed.
4
Read the check
Shelf Notes asks for storage and sidePanel, so both items sit under Its own settings only; Sites it can access and Browser features it uses both read "None." That’s what you’d expect from a notebook.
5
Allow and install
Click Allow and install. The workbench says where to find it: “It lives in the side panel: click Chrome’s side panel button in the toolbar and pick CRX Starter from the menu at the top.” Do that, and Shelf Notes opens in the side panel. Clicking the CRX Starter icon opens CRX Starter’s own popup, not the side panel.

Which ZIP to download from GitHub

A release usually lists three files: the author’s own ZIP (often named after the extension and version), "Source code (zip)" and "Source code (tar.gz)". Take the first. If the release has only the two source archives, open the README: some projects ship a ready-to-load folder in the source, others need npm run build first. If you drop an unbuilt source ZIP, CRX Starter tells you it isn’t an extension package rather than installing something half-made.

The Load unpacked way, for comparison

Chrome’s built-in route — loading the unpacked extension from a folder — still works. This is what each route asks of you:

	Load unpacked	CRX Starter
Steps	Unzip, open chrome://extensions, turn on Developer mode, Load unpacked, pick the folder	Drop the ZIP, read the check, Allow and install
Developer Mode	Must stay on	Off
Warning when Chrome starts	Possible — see the Developer Mode popup	No
See permissions before install	No	Yes
Unzipped folder to keep	Yes — delete it and the extension breaks	No

Updating to a new release

A ZIP has no update address, so it won’t update by itself. When a new release comes out, download its ZIP and drop it in. CRX Starter reads it, shows the check again — useful if the new version asks for more — and says "Installing this replaces Shelf Notes" before it swaps them. Curious why a .crx and a .zip behave differently? See how CRX and ZIP differ.

Your data on replace. Replacing clears the old version’s saved data. If the extension has an export option, use it before you drop in the new ZIP.

Have the ZIP already?

Add CRX Starter and drop it in as it is.

Add to Chrome — It's Free

Questions

My ZIP says "This isn’t an extension package". What now?

There’s no manifest.json in the archive. You probably downloaded "Source code (zip)" or a project that needs building first. Check the release assets or the README for a built version.

Do I need to build it first?

Only if the author ships source code. CRX Starter installs what is in the ZIP; it doesn’t run build tools. A release asset meant for users is normally ready to install.

Does it work with Microsoft Edge?

CRX Starter is on the Chrome Web Store first. Edge can install extensions from the Chrome Web Store, but we only test on Chrome for now.

Read next

Guide · 5 steps · 5 min readHow to Install a CRX File in Chrome (2026)Chrome refuses your .crx? Install it through CRX Starter in five steps — and read its permissions first.Guide · 4 steps · 6 min readHow to Load an Unpacked Extension in Chrome (and When to Skip It)Chrome’s Load unpacked route, step by step — the errors you’ll meet, and when a ZIP or CRX install is simpler.Note · 5 min readChrome Developer Mode Extensions: Why Chrome Asks You to Disable ThemDeveloper mode extensions are unpacked ones, and Chrome keeps warning about them. What they are, and how to stop the popup cleanly.Note · 7 min readWhat Is a CRX File? (CRX vs ZIP, and Is It Safe?)A .crx is a ZIP with a signed header in front. What the header holds, how it differs from a .zip, and when one is safe to install.