Getting a TEFL, TESOL or other certification is always recommended. It definitely makes your application stand out, and could even help you qualify for a higher salary.
Online TEFL courses have improved a lot in the quality of programing offered, and many people enjoy the convenience of getting certified from the convenience of home, or at a coffee shop or internet cafe.
Here are two recommended options for quality online TEFL/TESOL certification from established program providers whose certificates are recognized and accepted around the world.
Brigde Linguatec, Inc is the largest TEFL provider in the United States and offers educational and insightful certification courses.
i-to-i TEFL is the largest online TEFL provider and offers exceptional courses with the option of doing 100% online, or combining the certification with online instruction and classroom teaching.