Amazon Cookie Cleaner

About

Stop the "400 Bad Request - Request Header Or Cookie Too Large" error on Amazon and Seller Central in one click.

If you sell on Amazon or just shop there a lot, you've probably hit this error. Chrome suddenly refuses to load Amazon, showing a bare-bones "400 Bad Request" page. The standard fix is to delete all your Amazon cookies, which logs you out of every account and forces a full re-login. Then it happens again two weeks later.

Amazon Cookie Cleaner solves this surgically. It identifies the cookies your login session needs and keeps them. Everything else (tracking, advertising, analytics) gets deleted. The 400 error stops, you stay logged in, and you get back to work in seconds.

WHO THIS IS FOR

- Amazon sellers managing multiple accounts in Seller Central
- Power users running seller tool extensions like Helium 10, Keepa, Jungle Scout, RevSeller, Data Dive, Camelizer, or DS Amazon Quick View
- Anyone who has gotten tired of clearing all their Amazon cookies and re-logging in

HOW IT WORKS

The 400 Bad Request error happens when Chrome's request headers exceed the size limit Amazon's servers will accept. The biggest contributor is cookies. Amazon's tracking and advertising systems pile up dozens of cookies on your domain over time, and once you cross the threshold, every request gets rejected.

Most "fixes" tell you to clear all Amazon cookies, which works but logs you out of everything. This extension does the opposite. It keeps the cookies your login depends on:

- session-id, session-id-time, session-token
- at-main, ubid-main, x-main
- sess-at-main, lc-main, i18n-prefs
- Plus Seller Central session cookies

Then it deletes the rest. Tracking, advertising, analytics, and the various third-party cookies that pile up over time. The error stops happening because the request headers shrink back below the limit.

WHAT MAKES IT DIFFERENT

- Surgical, not nuclear: keeps your login, only removes tracking
- Source code is included so you can inspect exactly what it does
- No data collection, no analytics, no tracking
- No account required, no upsell, no subscription
- Works on amazon.com and sellercentral.amazon.com
- Built by Amazon sellers for Amazon sellers

HOW TO USE IT

1. Click the orange icon in your Chrome toolbar
2. Click "Preview" to see what would be cleaned without deleting anything
3. If the numbers look right, click "Clean Now"
4. The error stops happening, you stay logged in to Amazon

The extension shows you the date of your last cleanup so you can run it on whatever schedule works for you. Most users find weekly is plenty.

PRIVACY

This extension does not collect, transmit, or store any data outside of your browser. It does not phone home, log usage, or send your cookie data anywhere. The only data stored is the date of your last cleanup, kept locally so the popup can show "Last cleaned: [date]". You can verify all of this by reading the source code, which is included with the extension.

The only permission required is access to cookies on amazon.com domains, which is necessary to read and delete those cookies. The extension does not access cookies on any other site.

ABOUT THE BUILDER

Built by Welch Commerce Systems, an e-commerce automation consultancy for Amazon brands. We built this tool because we kept hitting the 400 error while managing client accounts and the existing solutions all required logging back into multiple Seller Central accounts every time.

Learn more at welchcommercesystems.com

SUPPORT

Found a bug? Have a feature request? Visit welchcommercesystems.com/tools/amazon-cookie-cleaner

The support page also includes a complete 6-step guide for preventing the 400 error from happening in the first place, so you can pair this extension with broader Chrome settings to stop the error completely.