Read a QR code without sending the image away
Choose a screenshot or image containing a complete QR square. The reader decodes it in your browser and shows the text inside. Authenticator QR images normally contain an otpauth:// setup link; ordinary QR codes may contain a website address or plain text.
What works best?
Use a sharp image with space around every edge of the code. If a photo fails, crop away unrelated content but leave the whole QR square visible. Files up to 12 MB are accepted. A clearer screenshot is usually easier to read than a photo taken at an angle.
Use an authenticator QR
After reading a TOTP setup QR, copy its setup link, open the authenticator and paste it into Authentication key. The decoded link can contain a setup secret, so treat its contents like the original QR.
About setup keysFormat reference: Google Authenticator key URI format.