Ajax Quiz
Tests Ajax fundamentals — making asynchronous HTTP requests with fetch and XMLHttpRequest, working with JSON, promises and async/await, handling errors, status codes and CORS, and updating the page without reloads safely and accessibly. Pass to earn Ajax and Fetch SOA-AJAX.
- Beginner difficulty.No experience needed: fundamentals and clear reasoning.
- 15 scenario questions
- 15 minutes, timed
- 70% to pass · 90% for distinction
- Free no sign-up needed
- LinkedIn-ready · add it to your profile in one clickSee how ↓
What is the Ajax Quiz?
The Ajax Quiz is a free beginner-level, 15-minute skill test from Science of Apps. It tests Ajax fundamentals — making asynchronous HTTP requests with fetch and XMLHttpRequest, working with JSON, promises and async/await, handling errors, status codes and CORS, and updating the page without reloads safely and accessibly. Score 70% or more on its 15 questions to earn a verifiable Ajax and Fetch certificate (SOA-AJAX). Every question is based on published standards and research — including Using the Fetch API (MDN Web Docs), JavaScript reference (MDN Web Docs), Cross-Origin Resource Sharing (CORS) (MDN Web Docs) — and each answer is explained with its source.
Built for your job title
Front-end developer, Web developer, Junior developer, Full-stack developer and Student — and anyone who wants quick, verifiable proof of Ajax skills for a CV or LinkedIn.
- Front-end developer
- Web developer
- Junior developer
- Full-stack developer
- Student
What the quiz covers
Three skill areas with 5 questions each, drawn from a bank of 10 per area, so a retake brings questions you haven't seen.
- 01
Requests and Responses
33%- fetch and XHR
- HTTP methods
- JSON
- 02
Async Code and Errors
33%- Promises and async/await
- Status codes
- Error handling
- 03
Security, CORS and UX
33%- CORS
- Security
- Updating the page
Based on published standards
The questions are original scenarios, and each one names the public standard, official guide or research it draws on — shown under the question while you answer, and linked in your review. These are the sources behind this quiz:
- Using the Fetch APIMDN Web Docs9 questions
- JavaScript referenceMDN Web Docs7 questions
- Cross-Origin Resource Sharing (CORS)MDN Web Docs3 questions
- HTTPMDN Web Docs2 questions
- HTTP response status codesMDN Web Docs2 questions
- Response Times: The 3 Important LimitsNielsen Norman Group1 question
- Retry behavior in AWS SDKs and toolsAmazon Web Services1 question
- Cross Site Scripting (XSS)OWASP1 question
- Cross Site Request Forgery (CSRF)OWASP1 question
- OWASP Cheat Sheet SeriesOWASP1 question
- Web Content Accessibility Guidelines (WCAG) 2.2W3C1 question
- HTTP cachingMDN Web Docs1 question
Try a sample question
Ajax lets a web page
- run only on the server
- replace HTML with Flash
- request data in the background without a full reload
- work only with XML files
Show the answer
C. request data in the background without a full reload — Asynchronous requests. The real quiz has 15 questions like this.
How the quiz works
15 minutes, 15 questions
One question per screen, with a progress bar and a countdown. Your progress is saved on this device if you need to pause.
Graded on our server
Answers reach the page only after you submit, so the certificate can only be earned by passing.
Every answer explained
Pass or not, you see every question with the right answer, why, and the source behind it. Pass mark 70%, distinction 90%.
Your certificate
Founder-signed, with a QR code and credential ID. Download PDF or PNG, add to LinkedIn, and it's emailed to you.
What you earn

Pass, then add it to LinkedIn in one click
No typing. The Add to LinkedIn button opens your profile’s Licenses & certifications form already filled in: the certificate name, Science of Apps as the issuer, the issue date, your credential ID and a link recruiters can use to verify it.
- 1Take the 15-minute test
- 2Score 70% or more
- 3Click Add to LinkedIn

Ajax and Fetch
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Frequently asked questions
What is the Ajax Quiz?
The Ajax Quiz is a free beginner-level, 15-minute skill test from Science of Apps. It tests Ajax fundamentals — making asynchronous HTTP requests with fetch and XMLHttpRequest, working with JSON, promises and async/await, handling errors, status codes and CORS, and updating the page without reloads safely and accessibly. Score 70% or more on its 15 questions to earn a verifiable Ajax and Fetch certificate (SOA-AJAX). Every question is based on published standards and research — including Using the Fetch API (MDN Web Docs), JavaScript reference (MDN Web Docs), Cross-Origin Resource Sharing (CORS) (MDN Web Docs) — and each answer is explained with its source.
How do I take the Ajax Quiz for free?
Read the three skill areas on this page, then take the 15-minute quiz online — no fee, course or sign-up. You see every answer explained when you finish. Score 70% or more and you get a Ajax and Fetch certificate straight away, on screen, as a PDF and by email, with a credential ID anyone can verify.
Are the Ajax Quiz questions based on real standards?
Yes. The questions are original scenarios written by Science of Apps, and each one is based on a public source you can read: Using the Fetch API (MDN Web Docs); JavaScript reference (MDN Web Docs); Cross-Origin Resource Sharing (CORS) (MDN Web Docs); HTTP (MDN Web Docs); HTTP response status codes (MDN Web Docs); Response Times: The 3 Important Limits (Nielsen Norman Group). The source is shown under each question and linked in the answer review. Science of Apps doesn't copy questions from other tests.
What does the Ajax Quiz cover?
Three skill areas with five questions each, drawn from a bank of 10 per area so a retake brings new questions: Requests and Responses (fetch and XHR, HTTP methods and JSON); Async Code and Errors (Promises and async/await, Status codes and Error handling); Security, CORS and UX (CORS, Security and Updating the page). Every question is an original scenario based on a published standard, official documentation or research, named under the question.
Who should take the Ajax Quiz?
Front-end developer, Web developer, Junior developer, Full-stack developer and Student. It suits anyone who wants a quick, verifiable way to show Ajax skills, from students and career switchers to experienced professionals.
Can I use this for ajax interview questions, javascript fetch quiz or ajax practice questions?
Yes. The Ajax Quiz is free and covers all of these: 15 scenario questions in 15 minutes, each answer explained with the source it comes from, so it works as interview and exam practice. It isn't a full course, so use the areas you miss as your study list. Scoring 70% or more earns a verifiable certificate.
Can I take the Ajax Quiz from any country?
Yes. The quiz is online, in English and free everywhere — people take it from India, the US, the UK, Europe, Africa, Latin America and Asia-Pacific. Your certificate is dated with your own local date and can be verified from anywhere at scienceofapps.com/certification/verify/.
How long is the Ajax Quiz?
15 questions — 5 from each of 3 skill areas — with a 15-minute limit. You need 70% (11 of 15) to pass and 90% for distinction.
How hard is the Ajax Quiz?
We rate it Beginner: no experience needed: fundamentals and clear reasoning. It has 15 scenario questions — 5 from each of 3 skill areas — and a 15-minute limit. You need 70% (11 of 15) to pass and 90% for distinction.
How much do Science of Apps certifications cost?
Nothing. There is no fee to take a test, to receive the certificate, to have it emailed or to verify it, and no sign-up.
How are the tests graded?
On our server, not in your browser. The answers never reach the page until you submit, so a certificate can only be earned by passing. Each certificate gets a unique credential ID stored by Science of Apps.
What happens if I don't pass?
You see your score for each area and every question with the correct answer and why, with the published source behind it. You can retake after 30 minutes, and the retake draws questions you haven't seen yet.
Do the certificates expire?
No. Every certificate is dated, so it always shows when you passed. Retake a test any time for a newer date or a higher score.
Can I add the certificate to LinkedIn?
Yes. After you pass, Add to LinkedIn opens the Licenses & certifications form with the certificate name, Science of Apps as the issuer, the issue date, your credential ID and the verification link filled in. You can also download it as a PDF or PNG, and it's emailed to you as a PDF.
How can an employer verify my certificate?
Every certificate has a credential ID and a QR code. Scanning it, or entering the ID at scienceofapps.com/certification/verify/, shows the holder's name, the certification, the score and the issue date from our records.
Are these accredited qualifications?
No. They are Science of Apps' own assessments of applied skill. They aren't issued by a university or standards body, and they work best alongside a portfolio that shows the skills in real work.
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