A Sandbox for Testing Before You Publish
Developer Mode gives you a safe way to try out an extension while you are still building it, checking how it behaves in a real browser before submitting it anywhere. It also lets you install internal tools or extensions shared by a colleague that were never meant for public distribution.
A Word of Caution
Because loading an unpacked extension skips the review process that store listings go through, only install code from a source you trust. An unpacked extension has broad access to your browser, so treat unfamiliar files the way you would any other unverified software.
Frequently Asked Questions
Does turning on Developer Mode make my browser less secure?
It does not weaken Chrome itself, but it does let you load any extension without a store review, so the safety of what you install depends entirely on trusting the source.
Can I remove an unpacked extension later?
Yes β go to the extensions page and click "Remove" on that extension, or simply turn Developer mode back off to hide it, though removing it fully is the cleaner option.