iniciar sesión
verbCEFR B1
What does “iniciar sesión” mean in English?
to log in to a digital account or platform by entering credentials; antonym: cerrar sesión
Example sentences
Intenté iniciar sesión pero me bloquearon la cuenta después de tres intentos fallidos porque había olvidado la contraseña.
I tried to log in but my account was blocked after three failed attempts because I had forgotten my password.
Para mayor seguridad, la aplicación te pide que verifiques tu identidad cada vez que inicias sesión desde un dispositivo nuevo.
For extra security, the app asks you to verify your identity every time you log in from a new device.
Si alguien inicia sesión en tu cuenta desde un lugar desconocido, recibirás una notificación de seguridad en tu correo electrónico.
If someone logs into your account from an unknown location, you will receive a security notification in your email.
How to use it
Iniciar sesión is the standard native-Spanish phrase for 'to log in'. It is a verb phrase — the infinitive is iniciar sesión (two words, no hyphen, no article required in most contexts). The full verb phrase conjugates on iniciar: inicié sesión, he iniciado sesión. The informal anglicism loguearse is widespread in colloquial speech but avoided in formal and written Spanish. Iniciar sesión always implies a secure credential check; it contrasts with cerrar sesión (log out) and with acceder (to access, which does not necessarily imply credentials).
Common mistake
The phrase is iniciar sesión (not *iniciar la sesión — the article is normally omitted in this fixed phrase). Loguearse is heard constantly in informal speech in Spain and Latin America but is not appropriate in formal writing. Iniciar sesión refers specifically to authentication on a system — do not use it for simply opening a website (that would be entrar en / acceder a).