Barcode (EAN-13, UPC-A, Code 128, ITF-14) and QR code images, PNG or SVG. Docs in Portuguese.
GeraCode API is a free Development API that requires no API key, is served over HTTPS and supports CORS, so it can be called from the browser.
Gere EAN-13, Code 128, ITF-14 e QR Code por URL. Funciona no Google Planilhas, no Excel 365 e em qualquer sistema. Grátis e sem cadastro.
Details from geracodigo.com.br.

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The GeraCode API is provided by GeraCode (geracodigo.com.br). Gere EAN-13, Code 128, ITF-14 e QR Code por URL. Funciona no Google Planilhas, no Excel 365 e em qualquer sistema. Grátis e sem cadastro.
Yes. The GeraCode API is listed in the Development category of the public-apis directory, which only includes APIs that are free or have a free tier. Check its documentation for rate limits and paid plans.
No. The GeraCode API requires no authentication, so you can start making requests without signing up.
Yes. The GeraCode API supports CORS, so front-end JavaScript can call it directly.
Yes. The GeraCode API is served over HTTPS, so it's safe to use in production.