Contact
Bugs, wrong numbers, tool ideas, or a privacy request — email me directly.
This is a one-person project, so replies are usually within a couple of days. Writing in English or Chinese is both fine.
Bug reports are the most useful email
If a calculator gives you a number that looks wrong, tell me the inputs you used and the result you expected. "Your fee calculator is off by a cent on a $24.99 sale" is worth more than a paragraph of praise — it directly turns into a fix.
Tool suggestions
If you're paying a subscription for something that takes ten seconds — merging PDFs, resizing an image, converting a CSV — describe the task and I'll consider building a free browser version of it.
Privacy and data deletion
Want your email address removed from the optional notification list, or your anonymous event data deleted? Email the address above and it will be done. See the Privacy Policy for what is and isn't collected.
Advertising and business
For anything related to advertising on this site, use the same address. QKitBox is not affiliated with eBay, Etsy, USPS, Shopify, Amazon, Pirate Ship, Meta or Google.