If you are unable to unlock 1Password on some of your devices, special characters may be the culprit. The most reliable Master Passwords use standard Latin letters, numbers, and symbols.
What are the standard Latin (ASCII) characters?
space (entered by pressing Space bar)
Why shouldn’t I use accented letters or characters from other languages?
Standard Latin characters are understood by all computers and devices. This is not always true for letters with accents or characters from non-Latin scripts , such as Cyrillic, Arabic, or Chinese.
Even if all your devices support special characters, they may not interpret those characters in the same way. The letter
à may look the same to you no matter where you enter it, but your computer and phone might not recognize it as the same character.
For this reason, using a character in your Master Password may prevent you from unlocking 1Password on some of your devices.
The geeky details
1Password has full Unicode support for Master Passwords and is therefore indifferent to character set and character encoding choice. It will use whatever is passed to it. The difficulty is that different operating systems and environments can hand a different chunk of data to 1Password depending on the system it was entered on, even if it appears to be the same.
For example, the glyph
ö might be passed to 1Password in different ways by the input system. Sometimes keyboard combinations (Option-U then o on a Mac) will give different results than, say, a single key press on a German keyboard layout. The character looks the same on your screen in either case, but the various input systems might be giving a different sequence of bytes to 1Password.
Although we haven’t intentionally limited the input for Master Passwords to certain character encodings, there may be cases where what is entered is not what 1Password receives. Unless you stick to a single platform and keyboard layout, the only really safe bet is to stick with old-fashioned US-ASCII.