Best Free AI Tools for Case Interview Prep (2026)

The best free AI setup for case interview prep pairs a general assistant (ChatGPT, Claude or Gemini) for role-play and math with one purpose-built case tool for a scored rep, because no single free tool does both. General assistants such as ChatGPT, Claude, and Gemini can support prompts, math, and role-play. Perplexity supports sourced research. Purpose-built case tools add fixed sequences and scored feedback. Choose by task, and verify current free limits before practice.

Free AI Case Interviews You Can Run Today

These four cases run with an AI interviewer that speaks, shows each exhibit when you reach it and scores your answer on every step.

Case (style, industry)	Quant difficulty	Qualitative difficulty	The math you run	Median time
UrbanBrew Coffee Margin Case (BCG, coffee chain). 6 (2 with math), 2 exhibits.coffee chainQuant difficulty mediumQualitative difficulty easy16 min· 117 voice runsTry free	medium	easy	Category gross margin, EBITDA recovery	16 min117 voice runs16 min, 117 voice runs	Try free
EV Charging Hub Profitability (McKinsey, energy and retail). 8 (3 with math), 3 exhibits.energy and retailQuant difficulty mediumQualitative difficulty medium17 min· 45 voice runsTry free	medium	medium	Segment profit bridge, percentage change	17 min45 voice runs17 min, 45 voice runs	Try free
HarborHealth Acquisition of MedLink Virtual Care (BCG, digital health). 8 (2 with math), 4 exhibits.digital healthQuant difficulty mediumQualitative difficulty hard27 min· 28 voice runsTry free	medium	hard	EV/EBITDA multiple, maximum justified offer	27 min28 voice runs27 min, 28 voice runs	Try free
Fruit Drink Turnaround (BCG, consumer packaged goods). 6 (1 with math), 1 exhibit.consumer packaged goodsQuant difficulty easyQualitative difficulty easy12 min· 25 voice runsTry free	easy	easy	Cost per pack gap, driver split	12 min25 voice runs12 min, 25 voice runs	Try free

Pick any row, then browse more in the case library.

How Can You Re-run the Same Test Across Tools?

Use this transparent protocol to compare current outputs yourself. Record the test date, plan, device, exact prompt, complete response, and any usage warning for every tool. Do not rank quality if a response or setting is missing.

1. Build an issue tree for a regional airline profit decline.
2. Read a simple exhibit and state the business implication.
3. Calculate the effect of a 5 percent volume decline when price and unit cost stay constant.
4. Give a final recommendation with evidence, one risk, and one next step.

Use the same instruction each time: reveal information one step at a time, do not give the answer early, and explain the grading method. Score each response only after you have saved the full transcript.

What Should the Re-run Record for Each Task?

Until that re-run preserves every transcript, choose a tool by its documented capability and your practice job. Do not treat this article as evidence that one tool produces better answers.

Which General AI Assistant Should You Use?

ChatGPT for spoken role-play

Use ChatGPT when you want to answer aloud and practice conversational pacing. Give it a strict interviewer role, ask it to reveal one fact at a time, and tell it not to rescue a weak answer.

Prompt: "Run an interviewer-led profitability case for a regional airline. Give one prompt, wait for my structure, and reveal data only when I request it. Challenge unsupported claims. At the end, separate evidence from opinion and review structure, math, analysis, and synthesis."

Do not describe free voice as unlimited. OpenAI's current Voice guidance, checked 2026-09-04, says free Live use is limited within a rolling 24-hour period and the limit can change.

Claude for long written context

Use Claude when you want to paste a longer prompt, compare two structures, or inspect a sensitivity chain. Ask it to preserve every case assumption and identify when it adds an assumption of its own.

Anthropic's current plan guidance, checked 2026-09-04, lists a limited Free plan. Do not rely on a named model or fixed message count unless the current plan page confirms it.

Gemini for a second explanation

Use Gemini when you want another explanation of a calculation or a fresh variation of a prompt. Ask it to show the equation, units, and business implication separately.

Google's Gemini limits guidance, checked 2026-09-04, says limits can change and free users can be limited first during high demand.

Perplexity for sourced industry context

Use Perplexity before a sector case when you need current, cited context. Ask for a small number of drivers and open the underlying sources. Keep outside research separate from the interviewer facts in the case.

Perplexity's official account guidance, checked 2026-09-04, says a free account includes five Pro Searches per day and three file uploads. These limits can change, so recheck the page before relying on them. Do not treat a sourced research answer as an interview score.

When Is a Purpose-Built Case Tool Better?

For solo practice, a general assistant is flexible because it generates the interviewer, case, and feedback from one prompt. That is useful for volume. It also means the evaluation can move when your wording changes.

A purpose-built platform can keep the prompt, sequence, exhibits, and scoring dimensions stable. Use that when you need a diagnostic you can turn into a next rep. Road to Offer combines full cases, targeted skill drills, and Learning Mode. Its score is training feedback. It does not predict a firm's hiring decision. To compare the purpose-built options side by side, see the best paid AI platforms for consulting prep ranking of six tools, and for the full practice method, how to practice case interviews with AI.

Which purpose-built AI case tools have a free trial?

Most purpose-built AI case tools let you try before paying, but the free part differs by pricing model: case-pack tools give a free try, subscription tools give a trial window, and Road to Offer gives one full case. Read what the free part includes and whether a card is needed before you start, because a trial window that opens on signup can expire before interview week.

The named tools, their prices and their case formats are compared in the AI case interview practice guide.

How Should You Judge AI Grading?

Before trusting any grade, ask five questions:

The strongest test is not whether an AI gives a precise number. It is whether the feedback identifies one observable behavior and the next rep shows whether that behavior changed.

Run one AI-graded case now. Put the result into the five checks above, then compare the feedback with the actual answer you wrote.

Try a real AI case interview for free

Consumer GoodsEasy

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Worked Examples From Real Practice Cases

Worked example: a coffee chain whose EBITDA halved

A BCG-style case: UrbanBrew, a regional coffee chain, saw EBITDA fall from $24M in 2023 to $12M in 2024 while revenue grew. The CEO wants the main cause and quick actions. This is the shape of an AI-graded rep: each step is scored, not just the final answer.

Clarifying question to ask: has the mix shifted toward lower-margin items, or is the pressure in labor and promotions? Traffic is stable, and sandwiches grew fastest.

Structure: revenue quality (traffic, mix, price), margin diagnosis (category gross margin), operating costs (labor, promotions), then a recovery plan with risks.

Key math from the exhibits:

Recommendation: go after labor productivity and promotion efficiency first, since labor is the largest headwind at $8M. Those two levers alone add $3.5M, reaching $15.5M. The $4M sandwich improvement is a supplied assumption, so test it in stores before counting it, and note that bakery also lost $4M of gross profit. Protect quality and traffic while you test.

The grader checks that you reconcile the bridge, avoid blaming sandwiches alone, and caveat the $4M. Run the full case with the interviewer asking each step.

Practice a real foodservice profitability case

FoodserviceEasy

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What Is a Seven-Day Free AI Prep Stack?

This schedule is a Road to Offer preparation plan example. Change it when your practice log shows a different weakness.

What Can AI Not Replace?

• Your recruiter instructions: The invitation defines the real format, office, and allowed tools.
• Human interaction: A practice partner lets you rehearse interruptions, rapport, and reactions that AI may not reproduce.
• Final-round judgment: Even human coaching cannot guarantee an offer. A score cannot guarantee how one interviewer will assess a recommendation.
• Truth checking: A fluent industry claim can still be wrong. Open primary sources and label assumptions.
• Your own synthesis: The candidate must decide which evidence matters and own the recommendation.

Which Exact Case Should You Run Next?

The EV Charging Hub case gives you a fixed profitability prompt, a full sequence, and scored feedback. Use it as the purpose-built case in the seven-day stack, then use the debrief to choose a matched structure, math, graph, brainstorming, or synthesis drill.

Practice a real energy profitability case

EnergyMedium

Start the free AI interview

Sources

• OpenAI Voice guidance, checked 2026-09-04
• Anthropic plan guidance, checked 2026-09-04
• Google Gemini limits, checked 2026-09-04
• Perplexity account guidance, checked 2026-09-04