As AI-powered apps and other technologies take the world by storm, the demand continues to rise for tech workers with these specialized skills. The number of job postings requesting AI skills is projected to increase by 297% during the next two years, according to Emsi Burning Glass, a market research firm. There were roughly 142,000 openings that listed AI skills as of January 2022, with median salaries of about $103,000, according to Dice.

Although the demand for these jobs continues to rise, there aren’t enough skilled workers to fill these positions. Only one in 10 workers report they have the education qualifications or career background to fill an AI job, a March 2023 report by Salesforce shows.

“There’s a disconnect between the skills companies are hiring for and those currently used by the workforce,” according to the study. “While four in five global workers report using digital skills in their day-to-day work, few report skills beyond collaboration technology, digital administration, and digital project management.”

While there are full-fledged AI degree programs—namely, a new master’s program in AI launched by the University of Texas-Austin—though some people may be more keen on a do-it-yourself route. If you’re interested in learning more about this in-demand field, several top tech firms and universities offer free online courses that serve as an introduction to AI technologies. Fortune has compiled a list of five online courses that are free to complete.

1. University of Pennsylvania: AI for Business

For someone who may be looking to break into AI or who wants to learn more about the applications of this new technology to different industries, the University of Pennsylvania offers a string of courses focused on artificial intelligence. The AI for Business specialization includes four courses: 

• AI Fundamentals for Non-Data Scientists
• AI Applications in Marketing and Finance
• AI Applications in People Management
• AI Strategy and Governance. 

These beginner courses take a total of about four months to complete and culminate in an applied learning project. Program participants complete peer-reviewed exercises to illustrate what they’ve learned about data analytics, machine learning tools, and people management. The specialization is taught by eight UPenn professors from the Wharton School, a top-ranked business school by Fortune, and other professors from the university. The courses are offered through online education platform Coursera, and students can earn a certificate that can be displayed on their LinkedIn profile.

2. Google: Google AI for Everyone

Google offers a beginner course for anyone who may be interested in how AI is being used in the real world. Google AI for Everyone, which is offered through online education platform EdX, is a self-paced course that takes about four weeks to complete, assuming you dedicate two-to-three hours per week to the course. Participants learn about both AI and machine learning principles and real-world applications of the technologies.

Google also covers what AI programming looks like and the process of teaching a computer how to learn. The course is taught by Laurence Moroney, who leads AI Advocacy at Google, and works on the Google Research into Machine Intelligence (RMI) team. Nearly 12,000 people have enrolled in this free online course, according to EdX.

3. University of California—Davis: Big Data, Artificial Intelligence, and Ethics

As part of its Computational Social Science specialization through Coursera, the University of California—Davis offers a course focused on AI: Big Data, Artificial Intelligence, and Ethics. During this four-week course, participants learn about big data and its limitations, the history of artificial intelligence, and research ethics. The entire course takes about 13 hours to complete.

The course is taught by Martin Hilbert, who is a professor at UC Davis and serves as a chair for computational social science. The course uses case studies to help participants learn AI concepts. So far, more than 23,000 participants have completed this course, and those who do earn a certificate that can be shared on LinkedIn.

4. Harvard University: Introduction to Artificial Intelligence with Python

If you’re one of the 4.3 million people who has taken Harvard University’s CS50 Introduction to Computer Science course through EdX, then the university’s introductory AI class might be the best option for you. CS50, which is one of the most popular free online courses of all time, is a prerequisite for Harvard’s Introduction to Artificial Intelligence with Python course.

This seven-week course covers AI algorithms, game-playing engines, handwriting recognition, and machine translation. Students have to commit between 10 and 30 hours per week to complete the course, which includes hands-on projects and lectures. The course is taught by David J. Malan, a renowned computer scientist and Harvard professor.

5. IBM: AI Foundations for Everyone

IBM, which is recognized as a revolutionary leader in emerging technologies, offers an AI Foundations for Everyone specialization through Coursera. The specialization includes three courses: 

• Introduction to Artificial Intelligence (AI)
• Getting Started with AI using IBM Watson
• Building AI Powered Chatbots Without Programming.  

The entire specialization takes about three months to complete, assuming you dedicate two hours per week to coursework. Students will learn the basics of what AI is, as well as its applications and ethical concerns. They’ll also hear from experts about starting a career in AI. The program is taught by Rav Ahuja and Antonio Cangiano, who work for IBM’s Skills Network. Participants earn a certificate upon completion.