Choosing between AI mock interview tools comes down to what you need reps in. For unlimited live voice interviews across coding, system design, and behavioral rounds, DevInterview.AI starts at $8.33 a month with the first interview free. Want a human FAANG interviewer? That is interviewing.io at roughly $180 to $340 a session. Need free? Exponent Practice (formerly Pramp) runs free peer mocks.
Disclosure: we build DevInterview.AI, and this is our blog. Every price below was checked against the vendor's own pages in August 2026, and the sources are linked at the bottom so you can verify. Where a competitor is the better choice, we say so.
Quick comparison
| Tool | Best for | Price | Free option |
|---|---|---|---|
| DevInterview.AI | Unlimited live voice SWE mocks | $19.99/mo, $49.99/qtr, $99.99/yr | First full interview, no card |
| interviewing.io | Human mocks with FAANG-level engineers | ~$180 to $340 per session | Free AI interviewer, limited peer mocks |
| Exponent Practice (Pramp) | Free peer-to-peer mocks | Free; $12 to $79/mo for full access | Yes |
| LeetCode Premium | Question bank with company tags | $35/mo or $159/yr | Large free tier |
| Hello Interview | System design self-study | $47/mo, $79/yr, $279 lifetime | Some free content |
| Final Round AI | Real-time interview copilot | From $25/mo | Limited free plan |
| Yoodli | Speech and delivery coaching | Free to $20/mo | 5 free sessions |
1. DevInterview.AI: best for unlimited live voice mock interviews
DevInterview.AI runs a full 30 to 45 minute session with a live voice AI interviewer: coding in a real editor with execution, system design on a diagram canvas, or behavioral with structured follow-ups. Problems are tagged by company, and every session ends with a detailed evaluation covering problem solving, code quality, language proficiency, and technical communication.
Pricing: $19.99 a month, $49.99 a quarter, or $99.99 a year. Every new account gets one free practice interview, no card required, and there is a 7-day money-back guarantee.
Where it wins: rep volume. Unlimited sessions means a mock every day costs less than one tenth of a single human session elsewhere. It is also one of the few tools that treats system design as a first-class voice interview, 45 minutes on a real canvas, rather than a text quiz.
Where it falls short: the interviewer is an AI. If you want hiring-manager judgment from a human who has run real loops, interviewing.io offers something we do not.
2. interviewing.io: best human mock interviews
Anonymous mock interviews with senior, staff, and principal engineers who make hiring decisions at FAANG and FAANG-adjacent companies. Feedback quality is the ceiling for the whole category, and the price reflects it. interviewing.io does not publish prices publicly, but 2026 third-party reviews consistently report roughly $180 to $340 per session depending on interviewer seniority, with multi-session coaching packages around $2,000. They also offer a free AI interviewer and a free peer-matching queue, though peer supply is limited.
Choose it when you are past the practice-volume stage and want one or two expert calibration sessions before a real onsite.
3. Exponent Practice, formerly Pramp: best free peer practice
Pramp merged into Exponent in July 2024, and its free peer-to-peer mocks now run as Exponent Practice. You get matched with another candidate and take turns interviewing each other over video with a shared editor. Free accounts get limited monthly credits; membership at $12 a month billed annually (or $79 month to month) removes the cap and unlocks Exponent's courses and question bank.
The tradeoff: your interviewer is another nervous candidate, not a trained interviewer. Feedback quality varies wildly, and every session needs a scheduled partner.
4. LeetCode Premium: the question bank, not a mock
LeetCode is not a mock interview tool, but it belongs in every comparison because it is where most people start. Premium at $35 a month or $159 a year adds company-tagged problems, timed mock assessments, and official solutions. Use it for volume drilling, and pair it with a voice tool: typing silently into an online judge teaches you nothing about explaining your approach out loud, which is the skill interviews actually test.
5. Hello Interview: best system design self-study
Strong written system design courses with guided practice and an AI tutor. Premium is $47 for a month, $79 for a year, or $279 lifetime, and none of the plans auto-renew, which is refreshingly honest billing. One important 2026 update: their live 1:1 mock interview and mentorship programs ended on May 31, 2026, so treat Hello Interview as a study resource now, not a mock interview service.
6. Final Round AI: a different category, the interview copilot
Final Round AI is best known for its Interview Copilot, which feeds you AI-generated answers in real time during actual interviews, and it also offers AI mocks and resume tools. There is a limited free plan, with paid subscriptions from $25 a month. Know what you are buying: using a copilot in a live interview violates most companies' interview policies, and detection keeps improving. As a pure mock practice tool it is serviceable, but that is not its center of gravity.
7. Yoodli: best for delivery, not content
Yoodli is an AI communication coach. It scores pacing, filler words, concision, and structure on any spoken answer. There is a free tier with 5 lifetime sessions, then Pro at $8 a month and Advanced at $20 a month, billed annually. It will not evaluate your algorithm or architecture, so use it as a supplement when the problem is how you talk rather than what you say.
How we evaluated
We checked every price against the vendor's own pricing page in August 2026 and linked each one in the sources below. Feature claims come from vendor documentation or our own testing. We build DevInterview.AI, so for the categories where a competitor is stronger, human calibration and peer practice, we said so directly.
What happened to Google Interview Warmup?
Google retired Interview Warmup in April 2026 with no announcement. The original URL now redirects to a generic interview-tips article. Plenty of older listicles still recommend it, which is a useful freshness test: if a guide lists Interview Warmup as a current option, it has not been fact-checked since spring 2026.
How to actually combine these tools
- Drill fundamentals on LeetCode. The free tier is enough for most people.
- Start voice mocks early. The most common failure mode we see is strong solvers who freeze when they have to think out loud. That skill only builds under realistic pressure, whether the interviewer is an AI or a human. Our guide on how to practice mock interviews with AI covers a week by week structure.
- Calibrate with a human one or two weeks before a real onsite if budget allows. This is where interviewing.io earns its price.
- Skip live copilots in real interviews. Beyond the ethics, depending on a tool under pressure is a plan that fails exactly when the stakes are highest.