A Google onsite is four or five 45-minute rounds, back-to-back. Most candidates prepare for it alone, grinding LeetCode in silence, and discover in round one that explaining a solution while you write it is a separate skill.
Mock interviews are the only prep that trains that skill. Someone watches you work, interrupts you, pushes on the weak spot and then tells you what they would have written in the feedback form. The six platforms below go about it in different ways, at prices from $0 to several hundred dollars a session.
The six at a glance
The short version: Prepfully for coaching tied to one company and role, interviewing.io for the hardest technical rounds, and Exponent when the budget is zero.
| Platform | Best for | Who interviews you | Price (USD) | Free option |
|---|---|---|---|---|
| Prepfully | Company and role specific loops: SWE, PM, data, TPM, EM | A coach from your target company | Mostly $89 to $189 an hour, $20 off the first | Question bank, interview guides, AI interviewer trial |
| interviewing.io | Coding and system design for engineers | An anonymous senior engineer | From $179 a session | One peer mock at sign-up |
| Exponent | High-volume practice, PM prep | Another candidate | About $144 a year for unlimited | 5 peer mocks a month |
| IGotAnOffer | PM and engineering manager loops | A coach picked by company and role | $100 to $250 an hour | Guides and YouTube mock interviews |
| Hello Interview | System design structure | Nobody (AI-guided practice) | $59 a month or $99 a year at list price | System design write-ups |
| Interview Query | Data science and ML roles | A data coach | $199 an hour (2024 price) | Coaching is paid only |
Prices were checked in October 2026. On the coach marketplaces every coach sets a rate, so treat the ranges as typical.
1. Prepfully
Prepfully is the best starting point for anyone interviewing at a named company. It has the widest coach roster on this list, and you can filter it by company and role at the same time. The site lists about 1,960 verified coaches across more than 1,600 companies, with close to 20,000 sessions completed.
That breadth matters more than it sounds. A Stripe engineering manager loop and a Meta data science loop have almost nothing in common, and a generic “ex-FAANG” interviewer can’t simulate both. On Prepfully you search for Product Manager plus Uber and get people who have worked in that role there.
What a session costs
Sessions run 60 minutes and each coach sets a price. Profiles sampled in October 2026 mostly fell between $89 and $189 an hour, with one outlier at $419. Prepfully itself puts the range at $50 to $300, averaging around $150.
- $20 off your first session
- Another 7 to 13 percent off when you book in bulk
- Sessions are anonymous
- The same coaches sell advice sessions and resume reviews, handy when you want to ask how a team’s hiring bar works before you practise against it
How to pick a coach
Every profile shows years of experience, review score, sessions completed and re-book rate. Use them. A coach with 39 sessions and an 87% re-book rate is a safer bet than one with a single review, however impressive the job title.
The free material
It’s better than you’d expect from a marketplace. There is a question bank fed by recent candidates, plus interview guides written for one company and one role at a time. If you have a Meta loop coming up, read Prepfully’s Meta software engineer interview guide before you book anything, so your first paid hour goes on practice instead of finding out what the rounds are.
Prepfully has also added an AI interviewer with a free trial. Treat it as a warm-up at 11pm when no human is available. It won’t replace a coach who has run the real loop.
Where it falls short
The weak points are the ones every marketplace has. Quality depends on who you pick, and some coaches have only a handful of sessions behind them. The bill grows quickly too: five mocks at $150 is $750. And if all you want is raw algorithm drilling with a senior engineer, the next platform is more specialised.
Best for candidates with a specific company and role in mind, especially PMs, data scientists, TPMs and engineering managers.
2. interviewing.io
interviewing.io is the most rigorous option here for software engineers. It runs anonymous technical mocks with senior and staff engineers from Google, Meta, Amazon and OpenAI, and it does very little else.
The anonymity is the point. You can bomb a graph problem in front of a Meta engineer and nobody knows who you are. Candidates who do well can also be introduced to hiring companies through the platform, which no other site on this list offers.
It is expensive
Single sessions start at $179 and pass $300 for some interviewers and topics, according to Lodely’s 2026 review, which also reports a dedicated coaching package at $2,000 for three sessions. There is a free peer mock when you sign up, and you earn more by interviewing other people.
Two limits
- It covers coding, system design, behavioural, machine learning and engineering management rounds. Product managers should look elsewhere.
- It tests you without teaching you. If you can’t yet solve a medium LeetCode problem in 25 minutes, a $200 session will only confirm that.
Best for engineers who are two or three weeks from an onsite and want a hard, honest read.
3. Exponent (which now includes Pramp)
Exponent is the cheapest way to get a lot of mock interviews, provided you accept that the person across from you is another candidate. It bought Pramp, the old free peer-practice site, and rebuilt it as Exponent Practice. If someone tells you to “just use Pramp”, this is where that advice now leads.
You get matched with a peer preparing for the same kind of round. For an hour you take turns as interviewer and candidate, then swap written feedback against a rubric. It covers coding, system design, SQL, behavioural and product management questions.
Free tier and pricing
Free accounts get five peer mocks a month. A subscription costs $79 monthly or about $144 for the year and unlocks unlimited sessions, the course library and company filters on the question bank, according to Lodely’s pricing breakdown. Take the annual plan. Two months of monthly billing costs more than twelve months of annual.
The ceiling on peer practice
Your partner has never sat on a hiring committee, so they can tell you that you rambled but not whether your answer would clear the bar for L5. Matches are hit and miss as well.
Exponent sells expert coaching too, starting at $200 or more an hour. At that price I’d book expert hours on Prepfully, where the average sits closer to $150, and keep Exponent for volume.
Who should use it
- Anyone in the first few weeks of prep
- Candidates on a tight budget
- Product managers, since PM interview content is where Exponent started
4. IGotAnOffer
IGotAnOffer is the closest thing to Prepfully on this list, a marketplace where you pick a coach by company and role and book an hour. It started in consulting prep, and that heritage shows in how structured its product management and behavioural coaching is.
Pricing runs on credits. One credit is $50 and an hour costs two to five of them depending on the coach, so $100 to $250, with volume discounts. Expect roughly 45 minutes of interview and the rest as feedback.
What it does well
- Free guides and YouTube mock interviews, particularly for PM and engineering manager loops. Watching someone else get grilled on a product sense question for 40 minutes is underrated prep.
- A refund if a session disappoints. Ask within 24 hours, limited to one session per user.
- Coaches are verified by ID check or a 30-minute call.
Why fourth and not second
IGotAnOffer splits its attention between tech, consulting and finance, while Prepfully is tech only and prints a re-book rate on every coach profile. For a TPM targeting Stripe or a data engineer targeting Netflix, that focus makes the search easier.
Best for PM, engineering manager and consulting-adjacent roles, and for anyone who wants a second marketplace to compare coaches against.
5. Hello Interview
Most lists still recommend Hello Interview for human mock interviews. That advice is out of date. The company ended its mock interview and mentorship programs on May 31, 2026.
It stays on this list because of Guided Practice, the best self-serve substitute for a system design mock. You work through a real question in stages and get feedback at each one:
- Requirements
- API
- Data model
- High-level design
- The hard parts
It now covers low-level design and AI-assisted coding rounds as well.
No subscription trap
Premium is a one-off payment that doesn’t auto-renew, listed at $59 for a month or $99 for a year, and usually discounted. The free system design write-ups are some of the best around.
But it isn’t a person
Nobody interrupts you halfway through your caching strategy to ask why you didn’t just use a queue, and that kind of interruption is most of what a system design round tests. Use it to get your structure solid, then pay for one or two human mocks elsewhere.
Best for senior engineers whose weak round is system design.
6. Interview Query
Interview Query is the specialist pick for data roles. Its coaches are data scientists, analysts and ML engineers at places like PayPal, Google and Databricks, and a session can run as a mock interview or as mentorship.
The last price it published was $199 for an hour or $549 for three. That figure dates from 2024, so confirm before you budget. Its real strength is the question bank, which goes deeper than any generalist site on:
- SQL
- Product metrics
- A/B testing
- Take-home case studies
Software engineers and PMs can skip it.
Best mock interview platform by interview type
Most engineering loops combine coding, system design and behavioural rounds. PM and data loops swap in their own. Pick for the round you’re weakest in.
| Interview type | Best paid pick | Best free or cheap pick |
|---|---|---|
| Coding and algorithms | interviewing.io | Exponent peer mocks |
| System design | interviewing.io | Hello Interview Guided Practice |
| Behavioural | A Prepfully or IGotAnOffer coach | Exponent peer mocks |
| Product sense and other PM rounds | A Prepfully coach from the target company | Exponent peer mocks |
| Data science, SQL and ML | Interview Query, or a Prepfully data coach | Prepfully’s question bank |
| Engineering manager and TPM | Prepfully | IGotAnOffer’s free guides |
Which one to book, and how many
Don’t start with a paid mock. Do three or four free peer sessions on Exponent first, so your $150 hour isn’t spent discovering that you forget to state assumptions out loud. A coach’s time should go on what a peer can’t see.
Then book an expert session about two weeks before the interview, which is earlier than feels comfortable. The first one always goes badly, and you need days to act on the feedback.
How many mocks you need
A common recommendation is five to eight mocks for a typical big-tech loop, spread across coding, system design and behavioural rounds. I’d make two or three of those paid and the rest peer or AI.
If two rounds worry you equally, spend the paid hour on the one where the company’s own style matters most. Amazon’s leadership principles and Meta’s product sense round are graded against house rubrics, and only someone who has used the rubric can tell you how you’d score.
Record everything
Record every session the platform lets you record. Hearing yourself say “so, basically” eleven times in one answer is unpleasant, and it works better than any written feedback.
Frequently asked questions
Are paid mock interviews worth the money?
Yes, for the two or three rounds where you need someone who has graded real candidates. Paying for every session is a waste, though, because a peer can catch the basic mistakes for free.
What is the best free mock interview platform?
Exponent. A free account gets five peer mocks a month across coding, system design, behavioural and PM questions, which covers most people’s first few weeks of prep.
Is Pramp still free?
Pramp no longer exists as a separate site. Exponent bought it and rebuilt it as Exponent Practice, where free accounts get five peer sessions a month.
Can an AI mock interview replace a human one?
No. AI interviewers are fine for getting reps in and tightening your structure, but they don’t interrupt you or push on a weak answer the way a person does. Use them as a warm-up and keep the human sessions for an honest read on where you stand.
How long does a mock interview last?
About an hour on most platforms. Prepfully sessions run 60 minutes, and IGotAnOffer splits the hour into roughly 45 minutes of interview with the rest as feedback.
How far ahead of the real interview should I start?
Start free peer sessions three or four weeks out, once you can solve problems on your own. Book the first paid mock about two weeks before the interview, so there are days left to fix what it turns up.
Do these platforms cover non-engineering roles?
Most do. Prepfully and IGotAnOffer have coaches for product managers, TPMs and engineering managers, Exponent is strong on PM practice, and Interview Query is built for data roles. interviewing.io is the exception and sticks to engineering.