Exam prep for licensing and certification
Most practice questions tell you what's right. CoStudy tells you why.
CoStudy is exam prep for professional licensing and certification — FINRA, CPA, CFA, NCLEX, PMP, CompTIA, AWS and more — with flashcards, multiple-choice questions and full-length timed practice exams. Every multiple-choice answer comes with a written rationale: the rule that decides it, and why each wrong option fails. K-12, AP and literature decks live in the study app.
Free readiness diagnostic. 30 questions, a projected score against the pass mark, your weakest domains and a plan to exam day.
Free to sample — no account needed · Web + iOS · Ad-free · One-time credential unlocks
Which bond has the greatest price volatility to interest rate changes?
- ALow coupon, long maturityLong maturity and low coupon maximize duration, producing the largest price swing.Correct
- BHigh coupon, long maturityHigh coupon reduces duration.
- CLow coupon, short maturityShort maturity reduces duration.
- DHigh coupon, short maturityBoth high coupon and short maturity minimize sensitivity.
The idea
A right answer you can't explain is a guess that got lucky.
Licensing and certification exams rarely ask you to recite. They ask you to apply a rule to a situation you haven't seen before. An answer key teaches you one item; a rationale teaches you the rule, so the next question — worded differently — is one you already know how to reason through. That is why every multiple-choice item in CoStudy names the principle that decides it and says why each wrong option fails.
The whole catalogue, on the web and in the iOS app.
How it works
Three steps from “studying” to “ready.”
Pick your exam
Start from professional licensing, IT and cloud, and admissions banks that follow the published exam outline, chapter by chapter. School, AP and literature decks are in the app if you need them.
Learn it by chapter
Work through flashcards and multiple-choice questions mapped to the outline's domains. Miss one and the rationale shows the rule you needed — and why the option you picked was wrong.
Know you're ready
For the SIE and Series 7, 65 and 66, a readiness score projects your result against the pass mark, by domain — not one blended percentage that hides your weakest area — and plans each day to the exam. For every exam, sit full-length timed practice exams weighted like the real thing.
What's inside
From the Series 7 to Security+ — 224 question banks, one app.
Professionals studying for a license sit next to candidates prepping for the SAT or GRE. Every public bank here is organised by its exam's own chapters, with flashcards, multiple-choice questions and practice exams — and your progress follows you between the web and your iPhone.
Start with a flagship exam page — each one is crawlable HTML with exam format, domain weights, a study timeline, an FAQ, and sample questions:
Then a study guide that links back to the matching bank:
Why CoStudy
Every question bank gives you answers. CoStudy gives you the reasons.
A typical practice test
An answer key and a score
- You find out you were wrong, not why
- Questions from wherever, not mapped to the published outline
- Last year's fees and thresholds stated as this year's rules
- One blended percentage that hides your weakest domain
- Ads and upsells between questions
Studying with CoStudy
A rationale for every answer
- Every multiple-choice item explains the right answer and each wrong oneThe rule that decides it, not just the letter.
- Chapters mapped to the published exam outlineQuestion counts follow the published weights.
- Checked for the tells that let you guess rightBanks are audited for answer-letter clustering and answer-length bias.
- Readiness by domain, not one blended scoreA free diagnostic and daily plan for the SIE, Series 7, 65 and 66, and CPA FAR, AUD and REG.
- Ad-free, with one-time unlocks for professional certificationsThe same account on the web and on iOS.
Who it's for
Built for the exam in front of you.
Pass the exam that gates your career
Licensing and certification exams are expensive to sit and costly to retake. CoStudy is built to get you through the first time.
- CPA, CFA, NCLEX, Series 7, SIE, PMP, CompTIA, AWS and more
- Timed practice exams weighted to the published blueprint
- Rationales that name the rule the exam is actually testing
- Study on your phone, pick up where you left off on the web
CPA FAR · CFA Level I · Series 7 · AWS Architect · NCLEX-RN · PMP
Browse professional certifications → Open professional banks in the app →From grade school to grad school admissions
Coursework and the tests that gate the next stage of school, in the same explain-every-answer format.
- SAT, ACT, GRE, LSAT, MCAT and GMAT
- Public practice pages for the admissions tests that still have them
- K-12, AP and literature banks live in the study app
- The same written-rationale format as the professional banks
Learn it together. Own it for good.
Open any bank and read real questions with full rationales, free. When you're ready, pick up where you left off — on the web or on your iPhone.