How to create an online test with answers and explanations

Grading tests by hand takes time, and students almost always get a score without understanding where they went wrong. An online test with an answer key solves the first part. The second part, understanding the mistake, depends on something few free tools offer: an explanation for every option, which students read as soon as they finish.

In this guide you will build a test like that on QuestioFlux, from scratch, and see exactly what students find in the answer key.

Who it is for

• Teachers who want to give exercises or practice tests without grading each one.
• Prep courses and schools that publish practice exams for students to train at home.
• Companies that run quick assessments after a training session.
• Self-learners who want to turn their own notes into a commented test.

Step by step

1. Choose "Online test (with answer key)"

Create your free account, click Create quiz and choose Online test. Fill in the cover: title, description, category, language and whether the test is public (it shows up in the site's search) or private (only people with the link can open it).

2. Write the questions and mark the right answer

In the editor, each question has a prompt and the options. The first option is always the right one, and it is highlighted in green. When people take the test, QuestioFlux shuffles the order, so the right answer is not always in the same place.

3. Add an explanation to each option

Under every option there is an Add explanation button, with up to 1,000 characters. The explanation is optional and stays hidden during the test: students only see it in the answer key, after submitting.

It is worth explaining the wrong options too, not just the right one. The wrong option is where you can address the most common mistake, the one the whole class tends to make.

4. Save it as a draft or finish it

You can save and continue another day: saving the questions does not publish the test. When it is ready, finish it. The test page shows its current state in a badge: Draft, Private or Public.

5. Share the link

Send the link to your class or embed the test on the school website. People taking it do not need an account: a student without one just types a name to show on the leaderboard.

What students see when they finish

As soon as a student submits, the answer key appears:

• the score and how many questions they got right;
• every question with its options, marking Your answer and the Correct answer, plus "Correct" or "Wrong" spelled out (not just a color);
• the explanations you wrote, on each option;
• filters to see only the wrong questions, only the right ones, or all of them.

After that, the student can retake the test or see the leaderboard with the class's times and scores. Anyone who does not want to appear on the leaderboard can hide their own activity in their account settings; the participation still counts toward the test total.

Sample questions with explanations

Math. What is 15% of 200?

• 30 (correct). Explanation: 10% of 200 is 20 and 5% is half of that, 10. Adding them up, 20 + 10 = 30.
• 15. Explanation: that is the percentage, not the value. 15% means 15 out of every 100, and 200 has two "100"s.
• 3. Explanation: the decimal point slipped here. 15% of 200 is 0.15 × 200 = 30, not 0.015 × 200.

Geography. What is the capital of Australia?

• Canberra (correct). Explanation: Canberra was planned to be the capital and sits between Sydney and Melbourne.
• Sydney. Explanation: it is the country's largest and best-known city, which is why the mix-up is so common.

Notice that the explanations of the wrong options do not just say "wrong". They show where the mistake comes from, and that is what students take into their next test.

Tips for a test that teaches

• One idea per question. Questions that mix two topics make the answer key confusing.
• Plausible options. An absurd option tests nothing; one that looks right at first glance tests understanding.
• Short explanations. Two or three sentences are enough. If you need more, the question probably covers too much.
• Review before finishing. Take the test yourself and read the answer key as if you were the student.

Free plan limits

Checked on October 28, 2026:

• Free: tests with up to 10 questions, up to 6 options per question, an explanation on every option, automatic grading, filters in the answer key, a leaderboard and sharing by link or embedding.
• Images on questions and options, more than 10 questions and more options require QuestioPlus ($2.50 per month) or a one-time pass ($1.99), which unlocks those features on one test. Once unlocked, the test stays editable even with no passes left.

Prices above are in US dollars. The site shows prices in Brazilian reais in Portuguese, and Spanish speakers can also pay in euros.

Frequently asked questions

Can students see the answers before finishing? No. The answer key and the explanations are only sent to the browser after the test is submitted.

Can I fix a question after the class has already answered? Yes, the test stays editable. Only changing the number of questions resets the leaderboard, because the old scores would no longer be comparable; the site warns you before saving.

Can the test be private? Yes. A private test does not show up in the site's search and only opens for people with the link.