Optional · bring your own key · browser-direct
AI capitalization, on your key.
Rules can't know that iPhone, eBay and McDonald's are cased that way — AI can. Paste your own Anthropic API key and your browser talks to the Claude API directly. This site has no server: we never see, store or pay for anything. You pay Anthropic; your key stays on your device.
How BYOK works
Your key, your browser, your call
Get a key
Create an API key at console.anthropic.com (a few cents of credit goes a very long way for text fixes).
Stored locally only
The key lives in your browser's localStorage on this device. It is never transmitted to us — there is no “us” server to transmit to.
Browser → Anthropic, direct
AI requests go straight from your browser to api.anthropic.com using Anthropic's documented direct-browser-access mode. Verify it in the network tab.
Remove anytime
One click deletes the key from your device. The rest of the site never needs it — everything else works fully offline.
FAQ
AI questions
Why do I need my own API key?
This site is free, has no accounts and no server. AI compute costs money, so the only honest model is: you bring your own key and pay Anthropic directly for exactly what you use. We never mark up, proxy or even see your usage.
What does it cost?
You pay Anthropic's standard API prices for the model you pick. Fixing the capitalization of a paragraph costs a fraction of a cent on Haiku and a few cents on Opus. There is no charge from this site, ever.
Is my text private when I use AI actions?
AI actions send your text to Anthropic's API under your key and their privacy policy — that's the trade for AI quality, and it only happens when you click an AI button. Everything else on this site (all 13 conversions, checker, slugs, counting) never leaves your browser.
Is putting an API key in a browser safe?
Use a dedicated key with a low spending limit for browser tools — you can create and revoke keys freely in the Anthropic Console. The key is stored only in this browser's localStorage; anyone with access to this device profile could read it, so don't use it on shared computers, and remove the key when done.