Which Sikh Guru introduced the Gurmukhi script in its standardized form?

Guru Angad introduced the Gurmukhi script in its standardized form.

Guru Angad, the second Sikh Guru, succeeded Guru Nanak in 1539 and led the community until 1552. He is traditionally credited with standardizing Gurmukhi, an abugida used to write Punjabi. The script made the Guru’s hymns more accessible to Punjabi-speaking followers and helped distinguish the Sikh literary tradition.

Gurmukhi means “from the mouth of the Guru.” It is written from left to right and uses a base line beneath which most letters are suspended. Punjabi written in Gurmukhi remains the principal script of Sikh scripture, although the Guru Granth Sahib also contains vocabulary and compositions from several linguistic traditions.

The script was not necessarily invented entirely by Guru Angad. Earlier related scripts existed in the region, and his historical role is best described as standardization and promotion. Gurmukhi is also used today for Punjabi literature, journalism, education, and official writing in the Indian state of Punjab.