Pass your API inspector exam the first time.
Practice questions, flashcards and timed mock exams for the API 510, 570 and 653 inspector exams, built on the codes on each effectivity sheet. Your Readiness Score tells you when you're ready for exam day.
The real dashboard, shown with sample student data.
Your API 510, 570 and 653 prep, in 48 seconds
Diana walks you through the dashboard: practice by topic, timed mocks, weak-spot tracking, flashcards, study notes and the Pass Guarantee.
Learn the reasoning behind every answer
API exams reward inspectors who know which code paragraph applies and can work the numbers. Every explanation walks through the calculation or the code rule behind the answer, so you learn why, not just what.
- Original questions written to each exam's effectivity sheet and Body of Knowledge
- Trap answers called out, like subtracting the corrosion loss once instead of twice
- Practice by topic or mixed, with instant feedback
See your weak spots before the exam does
Your Readiness Score day by day, accuracy by topic with the weakest first, and every timed mock exam against the pass line. One click on a topic starts a drill on it.
- Topic accuracy updates after every question
- Mock exam scores plotted against your target line
- The Today list sends you to your weakest topic first
Remember it on exam day, not just tonight
Spaced repetition brings each card back right before you'd forget it. Cards you miss return in 10 minutes. Cards you know wait days or weeks.
- Formulas, interval limits and code values that get tested closed book
- 15 new cards a day, so reviews never pile up
- Mastery feeds straight into your Readiness Score
Turn every missed question into a point
Every question you get wrong is saved with its explanation. It only clears after you get it right twice in a row, so lucky guesses don't count.
- Re-test all your mistakes in one click
- See the right answer and the code rule behind it
- Shows how many you've cleared, to keep you going
Walk in having done it before
Timed mocks with no feedback until you submit, the way exam day works. The closed-book part gives you about 1.5 minutes per question, so pacing matters.
- Closed-book pace: 110 questions in 2.75 hours, about 1.5 minutes each
- Quick 25-question mocks for a lunch break
- Two full simulations count toward the Pass Guarantee
What do you inspect?
Pick where you are. We'll show the exam to prepare for and a free practice test for it.
Built for the real exam, kept up to date
Every API inspector exam. One plan per exam.
Try any exam free first. Upgrade when you're ready.
Premium Monthly
- One API exam of your choice: API 510, 570 or 653
- 3,000 practice questions + 6 full mock exams per exam
- 800 flashcards + 60 key notes per exam, by topic, plus mind maps
- Spaced repetition + mistakes bank
- Readiness Score & detailed reports
- Video lessons as they release
- Content updates during your access
- 5 bonuses: inspector formula sheet, code section finder, study planner and more
- Pass Guarantee: complete the prep, pass or 100% back
Renews monthly until you cancel. Cancel in two clicks from your account; you keep access until the end of the month you've paid for. No minimum term.
Premium Yearly
- One API exam of your choice: API 510, 570 or 653
- 3,000 practice questions + 6 full mock exams per exam
- 800 flashcards + 60 key notes per exam, by topic, plus mind maps
- Spaced repetition + mistakes bank
- Readiness Score & detailed reports
- Video lessons as they release
- Content updates during your access
- 5 bonuses: inspector formula sheet, code section finder, study planner and more
- Pass Guarantee: complete the prep, pass or 100% back
Renews once a year until you cancel. We email you before each renewal. Cancel any time from your account; you keep access until the end of the year you've paid for.
Included free with every plan
API Inspector Formula Sheet
The corrosion, interval, thickness and test-pressure formulas API 510, 570 and 653 test most, on one printable page.
Free with an accountDamage Mechanism Quick Reference
The API RP 571 mechanisms named on the 510, 570 and 653 effectivity sheets: who gets them, where, and how to find them.
Exam-Day Checklist
What to check before your Prometric test center appointment, and how to pace the closed- and open-book parts.
8- and 12-Week Study Planner
A week-by-week plan that fits around inspection work and shutdowns.
API Certification Path Guide
From eligibility to certificate: experience rules, applications, exam windows, fees and recertification.
Pass, or get 100% of your money back.
We're confident in the system, so we put our money on it. Do the work, and if you still don't pass, you don't pay.
- Answer every question in that exam's question bank (100% covered)
- Read every study-notes topic for that exam
- Complete at least 2 full timed simulations, with your latest one at or above the exam's pass mark
- Reach a Readiness Score of 80 or higher (shown on your dashboard)
- Sit the official exam while your access is active, and within 60 days of meeting the requirements above
- Email your official result notice within 30 days of your exam date
Questions before you buy
Can I try it before I pay?
Yes. Open the study dashboard free with no signup, or take any exam's free practice test. You only pay when you want the full question bank, timed simulations and every study tool.
What if I buy it and it's not for me?
Because you get the full question bank and study materials the moment you pay, all sales are final. Try the free test and the free dashboard first so you know it suits you. The one exception is the Pass Guarantee: complete the full prep, and if you still fail, we refund 100%.
What if I study and still fail?
That's what the Pass Guarantee is for. Answer every question in the bank, read every study topic, pass 2 timed simulations and reach a Readiness Score of 80, then sit your exam within 60 days. If you don't pass, send your result notice within 30 days and we refund 100%.
Is it a subscription?
Yes. Premium is $147 a month per exam (about $4.83 a day) and renews monthly until you cancel. You can cancel in two clicks from your account, and there's no minimum term. Most people study for 1 to 3 months. If you want a whole year for one exam, the yearly plan is $1,323 for 12 months (3 months free) and renews once a year until you cancel.
How long do I keep access?
For as long as your Premium subscription is active. Cancel any time from your account and you keep access until the end of the month you've paid for.
Are these real exam questions?
No one can legally sell the actual exam questions. Ours are original questions written to API's published Body of Knowledge and the codes on each effectivity sheet, at exam difficulty, with an explanation for every answer and the code rule or calculation behind it, so you can check our work.
Is the content up to date?
We check every exam page against API's published certification pages, fee schedule and the Publications Effectivity Sheet for each set of exam windows, and show the date it was last checked. In November 2026 that included the exam format (170 questions, 140 scored, 110 closed book and 60 open book over 7.5 hours), the 2026 and 2027 fees and windows, API 510 11th Edition with the 2025 ASME Code, API 570 5th Edition with B31.3-2024, and API 653 5th Edition with Addendum 4 and API 650 14th Edition for 2027.
Do I still need the code documents?
Yes. The API and ASME codes and standards on your exam's effectivity sheet are your core reading, and they're the PDFs you search in the open-book part. We're the extra practice: more questions, timed mock exams, flashcards and a Readiness Score so you know when you're ready.
Are you affiliated with API?
No. APIInspectorExam is an independent exam-prep company, not affiliated with or endorsed by the American Petroleum Institute. API, API 510, API 570 and API 653 are trademarks of the American Petroleum Institute, and ASME is a trademark of the American Society of Mechanical Engineers, used only to describe the exams we help you prepare for.
Every API inspector exam
Each exam has a free practice test and a study guide. Premium adds 3,000 practice questions, 6 full mock exams, 800 flashcards and 60 comprehensive key notes per exam, organized topic by topic.
API 510 Pressure Vessel Inspector Exam
The API certification exam for in-service pressure vessel inspectors, based on API 510 and the documents on the effectivity sheet.
API 570 Piping Inspector Exam
The API certification exam for in-service piping inspectors, based on API 570, ASME B31.3, ASME B16.5 and the other documents on the effectivity sheet.
API 653 Aboveground Storage Tank Inspector Exam
The API certification exam for aboveground storage tank inspectors, based on API 653, API 650 and the other documents on the effectivity sheet.
API exam guides, written for inspectors
API 510 exam guide (2026-2027)
The API 510 Pressure Vessel Inspector exam is a 7.5-hour, 170-question computer-based test at Prometric test centers.
How to become an API certified inspector (510, 570 or 653)
API 510 (pressure vessels), API 570 (piping) and API 653 (aboveground storage tanks) are the main inspector certifications in refining and petrochemicals.
Your certification is one exam day away.
Open the dashboard, pick your exam and answer your first question in under a minute. Free, no signup.
Start studying freeReady to go all in? See pricing · $147/month per exam, about $4.83 a day · Pass Guarantee