You may file Form I-539, Application to Extend/Change Non-immigrant Status, online if you are applying as a single applicant (without co-applicants, or legal or accredited representation) to extend your stay and you hold status as a:
B-1 temporary visitor for business;
B-2 temporary visitor for pleasure;
F-1 academic student with a specific status expiration date;
F-2 spouse or child of an academic student with a specific expiration date;
M-1 vocational student; or
M-2 spouse or child of an M-1 student.
For more information, read the USCIS news release.