TEFL/TESL/TESOL vs CELTA Certifications: What’s The Difference?

ESL Certifications: What's the difference? You, probably.

When I first started looking for a job in Korea back in 2008, getting ESL certificated wasn’t on my radar. You didn’t need one to get a teaching position — in fact, I got a job at a public school in Seoul solely because I had a college degree and was a native English speaker. I had very little teaching experience, and certainly had no idea what I was getting into.

It wasn’t long after I arrived in Seoul that I decided to enroll in an online TEFL course. Standing in front of a room of 32 third graders who spoke literally zero English snapped me into reality — I couldn’t teach without any ESL education. It wasn’t fair to me or my students, and I suspected my professional life would be a LOT easier if I invested in some training.

Maybe your motivations for investing in a course are similar, or perhaps your school actually requires a certification. Fast forward to 2016 and a lot has changed for English teachers in South Korea. But where to start? If you spend just two minutes online you’ll find information about TEFL, TESOL, TESL, CELTA, and many more. Trust me, you’re not the first one to be confused! Now, let’s break it down: 

Course Length Don’t do anything less than 100 hours! Mix of online and in class. 4-5 weeks minimum,

up to 3 months. In class or online options available.

The Big, Wide World of ESL Qualifications

Let’s start with the basics and compare course costs, content and length, any pre-req’s you need, and of course, what all the acronyms mean.

Stands For: TEFL: Teaching English as a Foreign Language

TESOL: Teaching English to Speakers of Other Languages

TESL: Teaching English as a Second Language

Certificate in English Language Teaching to Adults

There are small nuances between the TEFL, TESOL and TESL, and for the most part they are used interchangeably these days. To employers overseas, they usually mean the same thing.

CELTA courses are affiliated with Cambridge University, and as a result, have a enjoyed a prestigious reputation in the ESL world for many years. CELTA has a major distinguishing factor from other certifications: Cambridge “external assessors” regularly monitor courses to ensure that teachers are following the syllabus, good training is being carried out, student assignments are on track and up to par, and that the grades being awarded are appropriate.

TEFL/TESOL/TESL are a dime a dozen these days, and could be anything from an easy 20-hour online course to a rigorous, month-long in-class course. Whether you choose online, in-class, or a course with supervised practice teaching, make sure you sign up for a minimum 100+ hours certification. Some schools may even require a 120 or 160 hour certification, so make sure you do your research before selecting a course.

If you crank out your CELTA full-time course at a certified CELTA Center, you should be able to get it done in just over one month. If you work on your CELTA part time at a CELTA Center, it will probably take you 2–3 months. There is also an Online CELTA course that combines online self-study with hands-on teaching practice.

100 or 120-hour TEFL/TESOL/TESL courses vary from a couple hundred dollars for an online course to $1,000+ for an in-class course. Be wary of any courses that cost less than $300 (like all those discounted courses on Groupon)… they say that you get what you pay for, and this is certainly the case in the world of online ESL certifications! If you’re going to invest in a course, do yourself the favor of choosing an accredited course that will actually help you in the classroom.

Average Cost $300 — Several thousand dollars $2,000+

CELTA courses are more expensive, but they’re typically much more in depth than a standard 100-120 hour online TEFL course. (And hey, you’ll be able to pay it back when you’re teaching abroad with no living expenses!)

Course Content 100+ course hours, plus practice teaching English Language Teaching to Adults

It really depends what kind of TEFL/TESOL/TESL course you choose. The more hours, the more in depth it will be. If you choose an only-online course, you’ll have between 12-15 modules to complete (with writing assignments and an online tutor). You may also have to prepare and “teach” a practice lesson. In class courses will be much more hands on, and may include some supervised teaching in an actual classroom.

A CELTA course will have 120 curriculum hours, plus you must complete 4 papers and teach for 6 hours (with teaching observation). More details on CELTA course content can be found here.



Varies Written task, phone interview, 18+, native English speaker

Some TEFL/TESOL/TESL courses will require a completed college degree, and most will require you to be 18 or older.

The CELTA application process includes a written grammar/vocab task, a 60-minute phone interview, and native English fluency.

Which ESL Course is Right For You?

Let’s be frank: only you can make this decision. You will have to spend time researching your options to find a course that works best for your budget and availability. The TEFL Shop was an amazing resource I used to help me filter through my options, and ultimately helped me find the 120-hour online Bridge TEFL course back in 2009. Everyone is different, so do lots of research on what you want to get out of your ESL certification and the kinds of schools you wish to be working with. Go forth and prosper!