Short answer
Each MBB firm screens applicants with its own online test between the resume review and first interview. McKinsey sends Solve, two or three ecology-themed games. BCG usually sends Casey, a chatbot-led case of about 30 minutes. Bain sends a Sova or TestGorilla reasoning test of about 30 to 40 minutes. Your invitation email sets the exact format.
Key takeaways
- The online test is step two at all three firms: after the resume screen, before any case interview. Each firm uses a different test, so prep for one does not fully cover the others.
- Firms publish very little. BCG and Bain state test length and allowed tools, and McKinsey puts the length in your invitation. Question counts and pass rates come from prep sites, which estimate that only about 20 to 30 percent of Solve and Casey takers advance.
- Percentage math and chart reading are core to all three tests. Build those first, then add firm-specific practice in the order of your application deadlines.
In this article
- Where do online tests sit in MBB recruiting?
- Which online test does each firm use?
- McKinsey: Solve
- BCG: Casey and the alternatives
- Bain: Sova or TestGorilla
- How are McKinsey, BCG and Bain online tests different?
- Which MBB online test is the hardest?
- Do you need to prepare for MBB online tests?
- Test-day setup that applies to all three
- How long do MBB online test results take?
- Can you prepare for all three tests at once?
- How do you choose a consulting assessment prep tool?
- What has changed in MBB online tests?
- Top articles
- More articles
A consulting online assessment is the test McKinsey, BCG and Bain send between your application and your first interview. The three tests have little in common: McKinsey uses games, BCG a chatbot case and Bain a multiple-choice reasoning test. This hub shows where the test sits in the funnel, which one each firm sends, how they differ, how long results take and what to prepare first. Each test has its own full guide: the McKinsey Solve guide, the BCG Casey guide and the Bain online test guide.
- estimated share of Solve takers who advance (prep-site estimate)
- 20–30%
- Source: hackingthecaseinterview.com
Where do online tests sit in MBB recruiting?
At all three firms the online test is the second gate: you apply, your resume is screened, and then an email brings a test link. You meet a consultant only if the test and your application together clear the bar.
The firms describe the step in similar terms:
| Firm | What the firm says about the step | Source |
|---|---|---|
| McKinsey | Solve is "one of the exciting steps in our process for most consulting roles", and results are "taken into consideration together with the rest of your application and any other assessment results" | McKinsey; Solve FAQ |
| BCG | The Online Case Experience "simulates the Case Interview experience and evaluates your problem-solving and analytical skills" | BCG Mexico |
| Bain | A consulting application "typically consists of different steps – a digital assessment and then case interview(s)" | Bain |
Two consequences follow. First, the test is not pass/fail on its own. McKinsey's FAQ says it will not decide your candidacy on Solve results alone. Second, the test is where most applicants exit. No firm publishes a pass rate, but prep sites estimate that only about 20 to 30 percent of Solve takers advance (Hacking the Case Interview) and give the same range for Casey (Road to Offer).
Which online test does each firm use?
The invitation email names your test. Find it here, then go to the full guide.
| Firm | Test name in your email | Format | Length | Full guide |
|---|---|---|---|---|
| McKinsey | Solve (older names: Problem Solving Game, PSG, Imbellus) | 2 or 3 ecology-themed games | Set by your invitation; reported as 65, 85 or 95 minutes | McKinsey Solve guide |
| BCG | Casey, Online Case Experience (OCE) | Chatbot-led business case plus a short video answer | About 30 minutes (BCG) | BCG Casey guide |
| BCG (some offices, alongside or instead of Casey) | Consulting Career Assessment (CCA), cognitive test, Pymetrics | Aptitude and behavioral games or questions | CCA about 30 minutes (BCG Mexico); others vary | Casey vs CCA |
| Bain | Sova or TestGorilla | Multiple-choice reasoning and judgment | About 30 to 40 minutes (Bain) | Bain online test guide |
McKinsey: Solve
Solve is a gamified assessment set in natural environments. McKinsey's FAQ says it "does not require previous business knowledge or gaming experience", that each task begins with an untimed tutorial, and that the length "is outlined in your invitation email" (McKinsey FAQ). It runs only on a PC or Mac, in English, Spanish, Portuguese or Japanese.
McKinsey does not describe the games. Prep sites report that current invitations contain Redrock Study (data research, calculations and a short report, about 35 minutes) and Sea Wolf (choosing microbes whose averaged traits meet each ocean site's targets, about 30 minutes). Longer invitations add the Sustainable Futures Lab, a judgment game introduced in March 2026 (Hacking the Case Interview; StrategyCase). Drill-downs: the Sea Wolf averaging rule, the Sustainable Futures Lab, how Solve is scored and calculator rules.
BCG: Casey and the alternatives
BCG calls its main screen the Online Case Experience: "an interactive exercise where you solve a business case guided by Casey, a chatbot". It takes "approximately 30 minutes", is conducted in English, and the case "can cover any industry or practice area" (BCG Mexico). Candidates report about 6 to 10 locked, sequential questions (Road to Offer) that open with dataset selection and end with a 60-second recorded recommendation.
Casey is not always the only test. BCG Mexico has Associate candidates take the Consulting Career Assessment (CCA) as well as the OCE, and says the CCA is "currently exclusive to the Associate recruiting process". Prep sites report a proctored cognitive test in some offices and Pymetrics behavioral games in others, and say Casey replaced the older Potential Test (StrategyCase). If your email mentions a case, it is Casey.
Bain: Sova or TestGorilla
Bain runs its digital assessment on two platforms and says the email will tell you which one. It "takes approximately 30-40 minutes", and a pen, paper and calculator are allowed for the assessment but not for later interviews (Bain). For TestGorilla, Bain says "no preparation is needed". For Sova, it points you to the sample questions on Sova's Candidate Preparation Hub.
TestGorilla's own candidate FAQ says you cannot go back to a previous question and wrong answers carry no penalty (TestGorilla). Prep sites report strict section timers on TestGorilla, while Sova mixes reasoning, situational judgment and personality items (Hacking the Case Interview). The side-by-side is in Bain TestGorilla vs Sova, and the numerical section has its own guide in Bain Sova numerical reasoning tips.
How are McKinsey, BCG and Bain online tests different?
All three screen for problem solving and analytical skill, but the experience differs in ways that change how you should practice:
| Dimension | McKinsey Solve | BCG Casey | Bain (Sova / TestGorilla) |
|---|---|---|---|
| What you do | Play simulations and make decisions with data | Answer a chatbot's case questions, then record a video | Answer multiple-choice items |
| Business knowledge | Not required (McKinsey) | Case skills in "any industry" (BCG) | Business judgment items, reported |
| Navigation and timing | Each game on its own timer; unused time does not carry over, reported | Forward-only, reported | No going back on TestGorilla (TestGorilla) |
| Tools | Pen and paper; no apps, websites, AI tools, outside calculator or prepared notes (McKinsey) | As stated in your invitation | Pen, paper, calculator (Bain) |
| What counts | Answers and, per prep sites, how you work | Answers, written responses and the video, reported | Correct answers, which TestGorilla converts to a percentile |
| Main pressure | Unfamiliar interface | Case thinking at chat speed | Seconds per question |
On scoring: TestGorilla, one of Bain's two vendors, says its percentile scores factor in question difficulty and compare you with a reference group of others who took the same test (TestGorilla). McKinsey and BCG publish no scoring method. For a firm-by-firm breakdown of formats and difficulty, see BCG Casey vs Bain Sova vs McKinsey Solve. For the aptitude-style formats, see cognitive aptitude test formats.
Which MBB online test is the hardest?
No firm publishes pass rates, so "hardest" depends on your weak spot:
- If you have never practiced a case, Casey is likely to hurt most. It asks for structure, math and a spoken recommendation with no interviewer to steer you.
- If unfamiliar interfaces slow you down, Solve is the risk. Much of its difficulty is learning each game under time pressure, which is why McKinsey gives an untimed tutorial for every task.
- If your mental math is slow, Bain's TestGorilla version is the risk. Prep sites put the pace at about 60 to 90 seconds per question.
Do you need to prepare for MBB online tests?
The official advice differs more than the tests do, and it is often misread:
| Firm | Official line on preparation | What it means in practice |
|---|---|---|
| McKinsey | "There's no need to prepare—just approach it with curiosity and creativity" (McKinsey) | No business knowledge is needed. But every task has an interface to learn, and the untimed tutorials are the only official practice |
| BCG | The case "can cover any industry or practice area", so "extensive study and practice of business cases are essential" (BCG Mexico) | Prepare as for a live case interview, in a chat-style, forward-only format |
| BCG (CCA) | "No preparation is needed" (BCG Mexico) | Know the format, then rest |
| Bain (TestGorilla) | "No preparation is needed" (Bain) | Content is general reasoning, but the timers are strict. Timed math practice still helps |
| Bain (Sova) | Review the sample questions on Sova's hub (Bain) | Do every official sample, then practice the item types under time |
"No preparation needed" means no content to learn, not an easy first attempt. Prep sites argue that knowing the interface improves speed and, for Solve, the reported process score (Hacking the Case Interview). McKinsey's FAQ also says no two candidates get the same parameters, so practice method, not memorized answers.
Test-day setup that applies to all three
- Device. McKinsey says Solve runs only on a PC or Mac, after a tech check. Bain asks for a laptop or desktop with a stable internet connection.
- Room. Book a slot when you will not be interrupted. McKinsey and Bain both say this.
- Camera. Candidates report a recorded video answer at the end of Casey and webcam monitoring on TestGorilla, so test your camera and microphone first.
- Technical problems. McKinsey says to contact its support team when a problem happens. If you do not, it "cannot make any exceptions to allow for reset" (McKinsey FAQ).
- Accommodations. McKinsey and Bain both offer accommodations for disabilities. Ask your recruiter before you start, not after.
How long do MBB online test results take?
Timelines vary by office and cycle. Here is what each firm states, and what candidates report:
| Firm | When the test arrives | Time to complete | When you hear back |
|---|---|---|---|
| McKinsey | After the resume screen, by email (reported) | A window of about 3 to 7 days, reported (StrategyCase) | About 1 to 14 days, reported (StrategyCase) |
| BCG | Associate candidates in Mexico: "the weekend immediately after the application deadline" (BCG) | About 30 minutes of test time (BCG) | News of an interview "a few days later"; deadline to offer "usually takes two to three weeks" (BCG Mexico) |
| Bain | After you apply, by email naming Sova or TestGorilla (Bain) | 30 to 40 minutes of test time (Bain) | "Within 60 days" (Bain) |
The practical reading: by the time your application is in, it is too late to start preparing. BCG's Mexico timeline puts the test days after the deadline, and prep sites report McKinsey windows of under a week. Start at least three weeks before your first deadline. The consulting assessment timeline maps this across a recruiting year, and what to do if you failed McKinsey Solve covers the waiting period if a result goes against you.
Can you prepare for all three tests at once?
Partly. Two skills are core to every test: percentage math and chart reading. Build them once and they pay off three times. The formats do not transfer, so each firm then needs its own practice.
A worked example of the shared skill: a client's margin rises from 12% to 15%.
| Question wording | Correct answer | Common wrong answer |
|---|---|---|
| "By how many percentage points did margin rise?" | 15 − 12 = 3 points | 25% |
| "By what percentage did margin rise?" | (15 − 12) ÷ 12 = 25% | 3% |
| "Margin rises by 10%. What is the new margin?" | 12% × 1.10 = 13.2% | 22% |
Prep sites name the percentage-point trap as one of the most frequent errors in Redrock (Hacking the Case Interview), and the same wording appears in case math and aptitude items.
If you are applying to more than one firm, this four-week sequence is our recommendation. Order the firm-specific weeks by application deadline, not by which test seems hardest.
| Week | Focus | Why |
|---|---|---|
| 1 | Shared core: timed percentage and growth math, chart reading | Core to all three tests |
| 2 | Earliest-deadline test: full format practice | Its invitation arrives first |
| 3 | Second test's format; one timed mock of the first | Keeps the first format fresh |
| 4 | Third test, or case interviews if you are already past a screen | Interviews can follow within days |
Two rules keep this efficient. Do not practice Solve like an exam. Its games reward a consistent method, so repeat full games rather than isolated questions. Do not practice Casey silently. Say your recommendation out loud against a 60-second timer, because the video is the part people skip.
How do you choose a consulting assessment prep tool?
Quality varies more than prices. Judge any tool on five points:
- Format fidelity. Does it copy the mechanics that matter, such as locked questions for Casey, hard section timers for TestGorilla, or multi-step games for Solve?
- Original content. Tools should build their own scenarios, not reproduce leaked items. McKinsey says no two candidates get the same parameters, so memorized answers would not help anyway.
- Per-question feedback. A score alone does not tell you what to fix.
- Clear independence. A good tool says plainly that it is not affiliated with McKinsey, BCG or Bain.
- Free sample first. Try a full sample before paying.
Our comparisons go deeper: best consulting assessment prep platforms, free vs paid prep and McKinsey Solve prep tools compared.
DrillCase is one of those tools, so here is what it covers: 20+ McKinsey-style scenarios in the Solve simulator, 25+ Casey-style chatbot cases in the Casey simulator, and 450+ Bain-style questions in 20+ test sets in Bain test practice. There are also 550+ math, chart and market-sizing drills, and the 60+ case library is free. All of it is independent practice, not affiliated with any firm. Plans are on the pricing page.
What has changed in MBB online tests?
| When | Change | Status |
|---|---|---|
| 2024 | Bain adds TestGorilla alongside Sova | Bain now names both; the start year is reported (Hacking the Case Interview) |
| Mid-2025 | McKinsey's Ecosystem Building game phased out for most candidates | Reported (Hacking the Case Interview) |
| March 2026 | Sustainable Futures Lab added to longer Solve invitations; a rebuilt 30-minute version (95-minute invitations) reported later | Reported (Hacking the Case Interview; StrategyCase) |
| 2026 | BCG Potential Test, already replaced by Casey, described as no longer in use | Reported (StrategyCase; Online Case Secrets) |
We re-check these facts against firm pages and candidate reports and update the date when anything changes.
Top articles
- McKinsey Solve guide: Redrock, Sea Wolf and SFL. The games, scoring, timing by invitation and a 3-week plan.
- BCG Casey online case: the complete guide. Question types, the video, scoring and a 2-week plan.
- Bain online test guide: formats and prep. Sova vs TestGorilla, section by section, with sample items.
More articles
- BCG Casey vs Bain Sova vs McKinsey Solve: MBB assessment comparison
- Consulting assessment timeline by firm
- Cognitive aptitude test formats
- Best consulting assessment prep platforms
- Free vs paid consulting assessment prep
- McKinsey Solve prep tools compared
- How McKinsey Solve is scored
- Failed McKinsey Solve? What to do next
- BCG Casey vs BCG CCA
- Bain TestGorilla vs Sova
Frequently asked questions
Do all consulting firms use online tests?
Not always, and not for every candidate. McKinsey calls Solve a step in its process for most consulting roles. Bain says intern and full-time consulting applicants may be required to take a digital assessment. BCG uses Casey in most offices and adds or swaps in other tests in some. Smaller firms vary, so check your invitation.
Which MBB online test is the hardest?
It depends on your background, and no firm publishes pass rates. Candidates without case practice tend to struggle most with Casey. People who dislike unfamiliar interfaces find Solve harder. Slow calculators feel TestGorilla's hard timer most. Prep sites estimate Solve and Casey pass rates at about 20 to 30 percent each.
When do you take the MBB online test?
After your application passes the resume screen and before your first interview. BCG's Mexico office, for example, says Associate candidates take their assessments the weekend immediately after the application deadline and hear about interviews a few days later. McKinsey and Bain send the test link by email after you apply.
Can you prepare for all three MBB tests at once?
Partly. Percentage math, chart reading and timed decision-making carry across all three, so train those first. The formats themselves do not transfer: Solve is a set of games, Casey is a chat-based case with a video answer, and Bain's test is multiple choice. Add firm-specific practice in the order of your deadlines.
Can you use a calculator or AI during an MBB online test?
Bain allows pen, paper and a calculator but bans AI tools and outside help. McKinsey bans applications, websites, AI tools and prepared notes during Solve, and its integrity page also lists a calculator, so use pen, paper and the in-game tools. BCG's rules come with your invitation. Use AI to learn beforehand, never during a live test.
Can you retake an MBB online assessment?
Usually not in the same recruiting cycle. For McKinsey Solve, prep sites report waits of 6 to 12 months, with some candidates waiting up to two years. TestGorilla links work once, and any retry is at the hiring firm's discretion. If a technical problem hits during Solve, contact McKinsey support at that moment, or it cannot reset your link.
Sources
- McKinsey & Company: Interviewing at McKinsey (Solve section)
- McKinsey & Company: Solve FAQs, August 2025 (PDF)
- McKinsey & Company: Assessment Integrity Expectations
- BCG Careers, Mexico: Online Case Experience (OCE) and CCA
- Bain & Company: Digital assessment
- Bain & Company: Interviewing
- Sova: Candidate Preparation Hub
- TestGorilla Help Center: Understanding percentile scoring
- TestGorilla Candidate Help: Common questions about assessments and tests
- Hacking the Case Interview: McKinsey Solve complete guide
- StrategyCase: McKinsey Solve guide
- Road to Offer: BCG online case (Casey) guide
- StrategyCase: BCG online case guide
- Online Case Secrets: BCG online case
- Hacking the Case Interview: Bain TestGorilla assessment