Do I need the bitcoincash: prefix?

No. Paste the address with or without it; UseQR strips a duplicate prefix so wallets never see bitcoincash:bitcoincash:…

Are legacy addresses supported?

Yes — base58 addresses starting with 1 or 3 are accepted alongside modern CashAddr addresses starting with q or p.

Yes. Amount (up to 8 decimals), label, and message all ride along as BIP-21 parameters that wallets display before sending.

Nothing, forever — no signup, no watermark, no limit on how many codes you make or how large you export them.

CashAddr or legacy address, with an optional amount and label. Free forever — no signup, no watermark, generated entirely in your browser.

Do I need the bitcoincash: prefix?: No. Paste the address with or without it; UseQR strips a duplicate prefix so wallets never see bitcoincash:bitcoincash:…
Are legacy addresses supported?: Yes — base58 addresses starting with 1 or 3 are accepted alongside modern CashAddr addresses starting with q or p.
Can I add an amount and a note?: Yes. Amount (up to 8 decimals), label, and message all ride along as BIP-21 parameters that wallets display before sending.
What does it cost?: Nothing, forever — no signup, no watermark, no limit on how many codes you make or how large you export them.