Zero Hour is the eBay sniper Chrome extension that runs entirely in your browser. It's the first major eBay sniper built as a true Chrome extension rather than a server-side service with a web dashboard. The difference matters: your eBay password never leaves your machine because the extension never asks for it.
Why a Chrome extension is the right architecture for sniping
For two decades, every eBay sniper has been a website. You'd visit gixen.com or esnipe.com, log in with credentials they collected, paste the eBay URL of the item you want, and trust them with the eBay login details you give them, stored on their servers. You don't have to risk your credentials to run auction snipes anymore.
A modern Chrome extension has everything a sniping tool actually needs without any of that risk:
- Your existing eBay session, carried natively by the browser tab that fires the bid. The extension never reads it, never stores it, never transmits it.
- Reliable scheduling with sub-second precision.
- Local storage, so your snipes live on your machine.
- System notifications that reach you across tabs.
- Content scripts, so the "Snipe this auction" button appears on every eBay listing.
None of those capabilities require a server. None of them require credentials. The first sniper to actually use them was Zero Hour.
What the Chrome extension does, end to end
1. Install
From the Chrome Web Store. Chrome shows two install warnings: access to your eBay sites, and permission to show notifications. The extension never asks for any login or signup.
2. Identity
The first time you open the popup, the extension generates a random ID for your install. That ID is used to check whether you are on Free or Pro. If you upgrade later, Stripe collects an email at checkout and your Pro plan is tied to that email, so you can activate Pro on another browser by typing the same email. The free tier needs nothing past the install ID.
3. Sniping
Two ways to add a snipe:
- On any eBay auction page: click the "Snipe this auction" pill that appears bottom-right. Item details load directly into the extension.
- From the extension itself: tap the plus (+) button, paste any eBay URL.
Either path lands you on the Add Snipe sheet: thumbnail, title, current price, end-time, max-bid input, and an advanced lead-time slider (default 6 seconds). Tap Save. The snipe slides into your Active list.
4. Firing
30 seconds before close, the extension wakes in the background. It opens (or reuses) a tab on the eBay listing so the page is loaded in its native context. At your configured lead time (default 6 seconds before close), the bid is submitted from the eBay tab. The result is displayed in the extension popup the next time you open it.
5. Notification
A system notification appears immediately: YOU WON. [item]. Final $X.
Permissions
At install, Chrome asks you to approve two things: access to your eBay sites (so the snipe button can appear on listings and the bid can fire), and permission to show notifications (so you know when a snipe wins, loses, or fails). The manifest declares a handful of additional narrow permissions that Chrome treats as silent (no install warning). The full breakdown of every line lives on the permissions page.
Source code transparency
Zero Hour ships unminified. Right-click the icon, choose Inspect popup, open Sources, and you're looking at the literal JavaScript executing on your machine. Variables have real names. Functions are commented.
This is rare. We think it should be the norm for any extension that touches sensitive accounts. A separately published GitHub repo can drift from what's actually shipped. The binary on your machine cannot.