Learning with e-learning and online courses is more popular than ever, yet studies or comprehensive practical experience are scarce. We want to change that – and have analyzed thousands of online courses. One result: Length matters! We explain the exciting findings and provide practical tips for your online courses.
Today, online courses exist for a variety of applications: Usually, trainers either rely on blended learning or e-learning. The difference: An online course for blended learning is only part of a training session that includes both online and in-person components. E-learning is typically a standalone, self-contained online course. However, all online courses share one goal: they should convey knowledge.
But what is the right length for an online course to be practically successful?
In this article, you will learn
how our mini-study was conducted.
the key findings in brief.
our tips for your online courses.
how the results were generated (in detail for statistics enthusiasts).
1. Evaluation of successful E-Learning and online courses
We analyzed over 8,000 courses on our online learning platform blink.it to identify the success factors for good online courses.
Evaluation by hand + eye
The evaluation was not done by a computer: Each successful course was examined individually and categorized as “e-learning” or “blended learning” based on its content. Why these categories are important, you will learn later.
What does “successful” mean?
We speak of “success” when an online course not only has a certain quality in terms of content (which we cannot comprehensively assess in our study) but especially regarding the motivation of the participants: Did the participants actually view the content? Did they not only start the courses but also complete them until the end? Therefore, the definition of “successful” in the context of our evaluation is:
“Your course is successful if all participants have viewed all content!”
We define the key figure for success as the “course completion rate”: This number indicates how many content pieces the participants viewed on average.
Example of the course completion rate
A completion rate of 10%, for example, indicates that participants viewed, on average, 10% of the content. A perfect course has a completion rate of 100%: that means 100% of the content was viewed by all participants!
Enough math for now! Here are the results of our evaluation:
2. Results: How course length influences e-learning success
Note: In the following, “successful” means a course completion rate between 75% and 100%.
In the following graphic, you will see a simplified view of the results of our evaluation: We examined how much content the courses have, and what types of courses they represent (e-learning or blended learning)
Graphic 1: Results from our course study. Successful courses with a maximum of 25 contents are mostly blended learning courses; successful courses with 25-75 blinks are predominantly pure e-learning courses.
2 key learnings from our study:
The majority of successful courses with at most 25 contents are blended learning courses.
The majority of successful courses with more than 25 contents are pure e-learning courses.
Thus, you can see that successful blended learning courses manage with significantly fewer individual learning contents – whereas successful e-learning courses can also be very successful with more learning contents.
The key factor is not only the number of contents but also their structure. Successful courses often consist of many small, clearly defined learning units rather than a few extensive modules. This structure makes it easier for learners to get started, increases the likelihood that they will begin the course, and simultaneously boosts the completion rate.
3. Our tips for your online courses:
We have 3 tips for you that you can use this knowledge for your next online course:
Tip 1: Keep your blended learning courses short and concise!
A blended learning course is a companion to in-person events and can therefore be shorter than a pure e-learning course: Not all learning contents need to be presented online. It is important to clearly demonstrate the connection between online and in-person learning for the participants. A blended learning course can serve as preparation for a live session, a follow-up to seminar content, or a complete support (before and after the in-person session).
Consider which contents fit well into your blended learning course. For preparation, you could, for example, survey the current knowledge level of participants. As follow-up, exercises that reinforce knowledge over several weeks are useful. Photo protocols of the in-person sessions are also perfect content for a short accompanying online course.
Tip 2: E-learning courses can be comprehensive – if the content is right!
Most successful e-learning courses at blink.it have more than 25 contents. Many even have more than 50, some even 100 individual learning units! If that sounds like a lot to you, consider that each learning unit (in our case: a Blink) is only a few minutes long.
In a pure e-learning course, you should not overwhelm participants with pages of text or hours of learning videos. What’s more important is to break the extensive learning material into small pieces. You might know this principle by the term “microlearning”.
We recommend learning units that can be completed by participants in no more than 5 minutes. So be sure to divide the learning material well and use different media: With a mix of short texts, self-made learning videos, and exercises, you can convey even extensive knowledge understandably and diversely.
Tip 3: Choose the right format for blended learnings and e-learning courses!
One of the most exciting results from our course evaluation is that both e-learning and blended learning courses can be very successful! We cannot and do not want to give you a clear statement “use method x”. What’s important is that you choose the appropriate format for your content. Success does not only depend on length but obviously also on the content!
Consider before creating an online course:
Are the contents suitable for a pure online course?
Or is support through appropriate in-person sessions more sensible?
Which media properly support my content?
How can I divide the entire knowledge into small learning units?
Then decide based on these questions whether a short online support or a detailed e-learning course is better suited for your planned measure!
4. For statistics enthusiasts: How were the results generated?
If you are wondering how we arrived at the results, we have an answer for you below.
The study design in detail
A total of exactly 8,257 courses were evaluated as a random sample from the countless courses on the blink.it learning platform. All courses on the platform that had at least 5 active participants and 3 contents (“blinks”) at the time of the evaluation were included in the selection. There was no upper limit, so there were also courses with over 2,000 participants and 100 blinks included in the evaluation.
The evaluation of the over 8,000 blink.it courses took place in 3 steps:
First, all courses were examined,
then only the successful courses.
Finally, the courses were categorized by course type to identify relationships.
Step 1: Review of all courses
In the evaluation, the completion rate was considered in relation to the number of blinks (contents) in the courses. Overall, this looked simplified as shown in the following graphic. Each point represents a course, corresponding to the combination of completion rate and content quantity:
You can see that many of the evaluated courses contain fewer than 25 blinks. Only very few courses have more than 75 contents. And most courses have a completion rate between 25% and 75%.
Step 2: All successful courses
Since we are interested in the most successful courses in the second step, we set a minimum completion rate of 75%. With this filter, the following picture emerges:
Here, two quite distinct groups become evident: One half of the successful courses has a maximum of 25 blinks (Group 1). The other half of the successful courses has significantly more blinks – starting from 25 upwards (Group 2).
Step 3: Successful courses by course type (e-learning or blended learning)
In the final step, categorization was applied: The courses were classified into the categories “e-learning” or “blended learning” based on their content.
The result of the categorization clearly shows:
The courses that are very successful with fewer than 25 contents are mostly blended learning courses for the preparation or follow-up of in-person events.
The online courses that are successful with a lot of content are predominantly pure e-learning courses focused on knowledge acquisition.
Disclaimer: The results of the evaluation relate exclusively to courses created on the learning platform blink.it. Results from other learning management systems and learning platforms may vary. Additionally, not all courses on the blink.it platform were included in the evaluation: this is a large-scale random sample of 8,257 courses. If you have questions about the study design or data evaluation, we are happy to assist you.
Conclusion
The optimal length of an online course does not derive from a fixed number of minutes or modules, but from the appropriate structure for the specific learning goal.
Our analysis shows that blended learning courses work particularly well with a few, targeted online contents, while pure e-learning courses may also be more extensive – provided that the learning material is sensibly divided into small units.
For you as a course developer, this means mainly one thing: Do not plan the length of your course first, but its learning structure. When the content is clearly organized, short enough for the everyday life of your participants, and methodologically diverse, the likelihood increases that your course will indeed be completed to the end.
A successful online course is therefore not the shortest or longest – but the one that is consistently focused on learning motivation and practical application.
Updated on 06.03.2026
